Wide-audience Scientific Seminars of
- 9th of July
Sensors: If a few can do so
much for so many, imagine what a network can do!
by Rui Rocha
Perhaps the first and most thorough concretization of Mark Weiser's
vision of Ambient Intelligence is the Wireless Sensor Network concept.
Indeed, such approach is based on the idea that computing is
pervasively integrated in the environment, becoming indistinguishable
from it. Moreover, underlying this concept is the assumption that
sensing a range of physical phenomena, rather than just data input,
becomes a key aspect of small, embedded computers that
communicate with each other to organize and coordinate their actions.
This talk will address the major challenges and opportunities
concerning Sensor Networks, presenting and discussing the key issues
that characterize this type of networks and what new networking
paradigms are involved in its design, deployment and operation.
[ECPS] Deborah Estrin, David Culler, Kris Pister and Gaurav Sukhatme;
Connecting the Physical World with Pervasive Networks; IEEE Pervasive
Computing, Vol. 1, No. 1, pp. 59-69.
25th of June
Quantum bits and their
by Yasser Omar
Quantum Information Theory is a new area of Physics and Information
Science that explores the strange properties of Quantum Mechanics to
encode, transmit, store and process information [D,BB]. Over the last
understood how to take advantage of these properties for revolutionary
applications, such as teleportation of quantum states, communications
protected against eavesdropping in a completely secure way or computers
astonishingly faster than the current ones (but for the time being
limited to a small number of quantum bits!). This rapid progress in the
field happened both at the theoretical and at the experimental level
contributed to improve our understanding of Quantum Mechanics. In this
talk I will try to present the essential ideas behind these
as well as the challenges for this new area of Science.
[D] D. Deutsch, Quantum theory,
Church-Turing principle and the universal quantum
computer, in Proc. R.
Soc. A 400, 97 (1985).
[BB] C. H. Bennett and G. Brassard, Quantum
key distribution and coin
tossing, in Proc. IEEE
Conference on Computers, Systems, and Signal
Processing, IEEE, New
York, 175 (1984).
11th of June
This "Seminário Seminal" revisits the original Tomasulo's paper
about his hardware algorithm [T]. Although it was proposed forty years
ago to exploit the existence of multiple execution units in old
computers, it is still a quite an important algorithm in nowadays
powerful general purpose processors. This algorithm associates simple
common data busing with a register tagging scheme to allow simultaneous
execution of independent instructions, while preserving the essential
precedences inherent in programs. It has played a central role to take
advantage of the exponential growing number of transistors available in
a chip (Moore law). The seminar is also a single tribute to the memory
of Dr. Tomasulo, recently deceased.
is so special in the
Tomasulo Hardware Algorithm?
[T] R. M. Tomasulo, An Efficient Algorithm for Exploiting
Multiple Arithmetic Units, IBM Journal, 25-33 (1967).
28th of May
When probabilities take the
leading role in finances
In 1997 Robert Merton and Myron Scholes won the Nobel Prize in
Economic Sciences, with their work on valuation of stock options, in
collaboration with Fischer Black, who died in 1995.
The famous Black-Scholes model is very interesting and rich, also
in math terms, as it in a certain way combines stochastic differential
equations and parabolic differential equations.
In this seminar we talk about this model, in the context of option
pricing. We will see why in this strange world we have strange
like Wiener processes, martingale measures, Itô integrals, ...;
After an excursion in this lunatic world, we will give two
particular examples of applications, different from option
Namely we will present, very briefly, the problem of relocation of
large companies and the investment in high speed rate services (like
the polemic investment in the TGV, in Portugal) using this kind of
At the end, the audience will have a clue of how brokers and big
investment companies price their services and assets!
[BS] F. Black, M. Scholes, The Pricing of Options and Corporate
Liabilities, Journal of Political Economy, 81 (3): 637-654
[M] R. Merton, Theory of Rational
Option Pricing, Bell Journal of Economics and Management
Science, Vol. 4: 141-183 (1973).
- 14th of May
and Nanotechnology of Thin Magnetic Films
The development of
artificial magnetic structures at the nanometric scale, and in
particular of thin films and multilayered systems, is related to the
new phenomena that were discovered in the last years, such as giant
magnetoresistence [*], interlayer magnetic coupling, magnetic tunnel
effect or spin dependent transport. The characterization of
structural, magnetic and transport properties by a set of techniques of
physics and material engineering has had a relevant role in the
research for new systems and phenomena and for their technological
This talk will present both the standard principles and the current
practice in the deposition of various magnetic nanostructures and its
spectroscopic characterization by nuclear resonance methods, and will
highlight the state of the art, the difficulties, and the current and
[*] M. N. Baibich,
J. M. Broto, A. Fert, F. Nguyen Van Dau, F.
Petroff, P. Eitenne, G. Creuzet, A. Friederich and J. Chazelas, Giant magnetoresistance of (001)Fe/(001)Cr
magnetic superlattices, Physical Review Letters, vol. 6, num. 21
[*] G. Binasch, P.
Grünberg, F. Saurenbach and W. Zinn, Enhanced magnetoresistence in layered
magnetic structures with antiferromagnetic interlayer exchange,
Physical Review Letters, vol. 39, num. 7 (1989).
Interpretation: The Genie inside Compiler Data Flow Analysis
por Pedro Diniz
Abstract interpretation is the basic technique at the core of
all static data-flow analyses used in advanced compilers today.
It allows compiler to reason at compile time about values computed
at run-time. Despite its inherent limitations, the results of these
enable compilers to perform sophisticated transformations that
lead to increased program performance metrics while guaranteing the
fundamental cornerstone of any compiler transformation: correctness.
In this talk we will show through a simple example the use of abstract
interpretation and motivate its generalized use in the definitions of
data-flow analysis frameworks.
Cousot and R. Cousot, Abstract interpretation: a unified lattice model
for static analysis of programs by construction or approximation of
fixpoints, In Conference Record of the Sixth Annual ACM SIGPLAN-SIGACT
Symposium on Principles of Programming Languages, (1977), 238--252.
Carbon Based Servers and Organizational Self-Awareness
por José Tribolet
Individual Self-awareness is a
effective action, decision-making and learning processes. Self-aware
know who they are, how they do things and what they (and others) are
any particular moment. Whereas innate in individual human beings,
self-awareness in organizations must be built and maintained by
interactions among their members. Although currently supported by a
IS/IT tools, organizational self-awareness is typically fragmented,
inconsistent and most of all, outdated. The use of organizational
a promising means in achieving this end. However, this is a challenging
requiring the integration of several approaches and the definition and
implementation of model acquisition mechanisms.
From our point of view,
enterprise models are an
essential communication tool in supporting and enhancing organization’s
self-awareness. Organizational modeling has a long tradition in
and management sciences. In these fields, the main goal is to provide
thinking about the organization and to produce management principles
theories based on these ways of thinking. These models, described in
language and with a high level of abstraction, are limited to human use
lead to different interpretations.
Computer Science and
Engineering have also addressed
organizational modeling activities. These models are commonly referred
Enterprise Architectures or Enterprise Ontologies and aim at
design and implementation of Information Systems and Technologies
aligned with organizations. IS/IT models are mainly used as
Consequently, they are described using more formal syntax and
enabling its processing by automated agents and reducing inconsistent
interpretations. However, current enterprise representations are
restricted to concerns relevant for participants and stakeholders of
development, acquisition or implementation projects. Moreover, these
assume a rather static, mechanistic and deterministic view of the
Modeling the organization
for its self-awareness is a
much more challenging task. It requires integrating approaches coming
organizational and IS fields, to capture: (1) structural and dynamic
(2) formal (hard) and informal (soft) sides and (3) different
levels of details of organizations. Moreover, it entails capturing
A first step in achieving
this end is the definition of a
conceptual framework to enable the construction of several types of
of representing organizational routines, as well as deliberation and
processes. This conceptual framework must also allow the mapping
The new field of
Organizational Engineering attemtps to provide
solid scientific basis for such an holistic, integrated and dynamic
frework, capable of supporting the emerging bionic properties of the
Organizations of the XXI Century, which are truly semantic webs of
(i.e. Humans) and silicon-based servers (i.e. Computers), dinamically
through their transactions the enactment of the organizational
The Library of Babel --
Information and Entropy
The books of the library of Babel [B] contain every possible
of just a few basic characters (letters, spaces and punctuation marks).
Though the majority of the books in this universe are pure gibberish,
the library also must contain, somewhere, every coherent book ever
written, or that might ever be written, and every possible permutation
or slightly erroneous version of every one of those books.
not all characters appear with the same probability, the probability is
defined by the corresponding language in which we write or read the
book. The corresponding probability can be represented by the
information, known as information entropy, which is usually expressed
average number of bits needed for storage. Bit, introduced 1944 is the
smallest information unit corresponding as quantity of yes-or-no
answers. We can represent each character by some bits. Each bit must be
stored in a state of some physical system.
The real physical world gives
us the ability to represent superposition of bits, the so
called qubits. It means a one and a zero exist at the same time and
can be manifested in two different (physical) worlds. Qubits give us a
way to represent the library of Babel in form of a book.
The book represents the superposition of all possible books. We can
increase our chance of accessing a more meaningful book in our own
world with the aid of Unitary operators which manipulate the
[B] J. L.
Borges, La biblioteca de
Babel, in Ficciones
12th of March -- Opening
Geometry and Topology
by Miguel Abreu
The last 25 years have seen
plenty of mathematical developments where
the word "symplectic" shows up, i.e. where a "skew-symmetric
non-degenerate bilinear form" determines the questions under
Some of these developments are said to be part of Symplectic Geometry,
while others are said to be part of Symplectic Topology.
For example, questions related with the "moment map" and the
"Atiyah-Guillemin-Sternberg convexity theorem" (cf. [A] and [GS]) are
usually considered as part of Symplectic Geometry, while questions
related to "holomorphic curves" and "Gromov's compactness theorem"
(cf. [G]) are usually considered as part of Symplectic Topology.
The first part of this seminar will be an introduction to symplectic
mathematics. In the second part the Geometry/Topology dichotomy will
be illustrated through the discussion of the following two problems:
- Geometry: study of "symplectic toric manifolds";
- Topology: study of the "symplectomorphism group" of a
The meaning of all the expressions under quotes in this abstract will
explained during the seminar.
[A] M. F. Atiyah, Convexity and
commuting Hamiltonians, Bull. London Math. Soc. 14 (1982), 1-15.
[GS] V. Guillemin and S. Sternberg, Convexity
properties of the moment mapping, Invent. Math. 67 (1982),
[G] M. Gromov, Pseudo holomorphic
curves in symplectic manifolds, Invent. Math. 82 (1985),
If you would like to contribute with a presentation or sugest a speaker
to be invited, contact ana.matos@ist ...