Seminari periodici
- SIA: Seminario Interdipartimentale di Algoritmi- GRoW IR: Group Reading on Web Information Retrieval
- Security Group Meetings
- Sm@rt
- Theory (Reading) Seminar
Seminari
| 21/03/2012 - 9:30 - Aula Alfa |
| Bussole, attrezzature e suggerimenti per il mondo del lavoro |
| abstract: Giornata dedicata a iniziative formative da parte di esperti del gruppo Shenker e di una sociologa del lavoro e consulente per la selezione del personale, Luciana D'Ambrosio Marri. Per consentire la massima partecipazione, la didattica sarà sospesa per il terzo anno della Triennale e per la Magistrale. Per maggiori informazioni consultare: |
| 21/03/2011 - 12:00 - Aula Alfa |
| InnovAction Lab |
| oratore: (vedi documento allegato) |
| abstract: InnovAction Lab e' il primo percorso formativo gratuito per diventare imprenditori le cui selezioni sono aperte a tutti gli studenti dei nostri corsi di laurea (triennali e magistrali). Per maggiori info: clicca qui |
| 13/01/2011 - 12:00 - Aula seminari |
| Programming in pictures |
| oratore: Prof. Nikolay Mirenkov - Università di Aizu (Giappone) |
| abstract: Programming in pictures (or filmification of methods) is an approach where pictures and moving pictures are used as (super-) characters to represent algorithms. Within this approach algorithms are considered as activities in 4-D space-time where some 'data space' is traversed by a 'front of computation' and necessary operations are performed during this traversal process. There are compound pictures to define algorithmic steps (called Algorithmic CyberFrames) and generic pictures to define the contents of compound pictures. Compound pictures are assembled into special series to represent predefined algorithmic features. A number of the series is assembled into an Algorithmic CyberFilm. In this presentation, the concept and fundamental features of CyberFilm programming technology will be explained and examples of programs will be demonstrated. An idea of programs as media for human (programmers) communication will also be discussed. |
| 12/11/2010 - 11:00 - Aula Alfa |
| Concrete mathematical incompleteness |
| oratore: Prof. Harvey Friedman |
| abstract: An unprovable theorem is a theorem about basic mathematical objects that can only be proved using more than the usual axioms for mathematics (ZFC = Zermelo Frankel set theory with the Axiom of Choice) - and that has been proved using standard extensions of ZFC generally adopted in the mathematical logic community. The highlight of the talk is the presentation of a new unprovable theorem concerning the structure of kernels in discrete and finite directed graphs. We first review some previous examples of unprovable theorems. (1)-(5) are unprovable in the weaker sense that any proof demonstrably requires some use of logical principles transcendental to the problem statement. These previous contexts include: (1) Patterns in finite sequences from a finite alphabet; (2) Pointwise continuous embeddings between countable sets of reals (or, more concretely, rationals); (3) Relations between f(n_1,...,n_k) and f(n_2,...,n_k+1); (4) Homeomorphic embeddings between finite trees; (5) Borel sets in the plane and graphs of one dimensional Borel functions. (6) Boolean relations between sets of integers and their images under integer functions. (7) Structure of Kernels in Digraphs. |
| 28/09/2010 - 9:30 - Auditorium del Goethe Institut, Via Savoia 15 |
| Lectio Magistralis: 'The quantitative analysis of user behavior online' |
| oratore: Dott. Prabhakar Raghavan |
| abstract: L'attività didattica della mattina del primo giorno di lezione 18 ottobre 2010 consisterà nella lectio magistralis del dott. Prabhakar Raghavan, direttore generale di Yahoo! Research e vice-presidente di Yahoo!, una figura tra le più carismatiche dell'informatica mondiale. Tutti gli studenti dei corsi di studio in Informatica, dal primo anno all'ultimo, sono invitati a partecipare. La locandina relativa all'evento è disponibile a questo link. |
| 24/06/2010 - 12:00 - DI, Aula Seminari |
| How hard is to compute the crossover distance? |
| oratore: Prof. Victor Mitrana |
| abstract: A basic problem in the area of combinatorial algorithms for genome evolution is to determine the minimum number of large scale evolutionary events (genome rearrangements) that transform a genome into another one. This talk is devoted to the algorithmic study of genome evolution by crossover/translocations. We consider chromosomes as being linear strings that exchange prefixes with each other in the crossover process. A few crossover distances are considered and some exact and approximation algorithms for computing them are discussed. |
| 13/06/2008 - 15:00 - Aula Riunioni - Dipartimento di Informatica |
| Maintaining Consistency in Layered Architectures and Composition and Independence of High-Level Net Processes |
| oratore: D.ssa Kathrin Hoffmann |
| abstract: We present a layered architecture for modeling workflows in Mobile Adhoc NETworks (manets) using algebraic higher order nets (AHO nets). Workflow in manets can be adequately modeled using a layers architecture, where the overall workflow, the team members activities and the mobility issues are separated into three di erent layers, namely the workflow layer, the mobility layer and the team layer. Dividing the AHO net model into layers consistency that mainly requires that the team layer is given by the mapping of the individual members' activities to the gluing of the workflow and the mobility layer. The main results concern the maintenance of the layer consistency when changing the workflow layer, the mobility layer and the team layer independently. Moreover, we give an adequate semantics for AHO nets. Based on the notion of processes for low-level Petri nets we analyse high-level net processes defining the non-sequential behaviour of high-level nets. In contrast to taking low-level processes of the well known flattening construction for high-level nets out concept of high-level net processes preserves the high-level structure. The main results are the composition, equivalence and independence of highlevel net processes under suitable conditions. Independence means that they can be composed in any order leading to equivalent high-level net processes which especially have the same input/output behaviour. Tutti gli interessati sono invitati a partecipare. |
| 05/06/2008 - 14:30 - Aula Riunioni - Dipartimento di Informatica |
| Euler Diagram Visualisation |
| oratore: Dr. Andrew Fish |
| abstract: Euler diagrams form the basis of many diagrammatic notations used to represent set theoretic relationships in a wide range of contexts including: file system information, statistical data representation, object-oriented modelling, logical specification and reasoning systems, and database search queries. We provide an overview of some of these modern applications and consider a problem essential to these applications - the Euler Diagram Generation Problem. That is, given an abstract description of a diagram can we automatically produce an appropriate diagram? Many factors can impinge on this question, such as which topological or geometric constraints are to be imposed on the diagrams (e.g. whether multiple curves can intersect at one point, whether curves are allowed to be concurrent, etc), and further extensions to the setup include adding requirements that the regions satisfy area proportionality constraints, for example. We discuss these issues and provide a solution to an instance of the Euler Diagram Generation Problem. |
| 07/04/2008 - 12:00 - Aula Alfa, Dipartimento di Informatica |
| Infinite Games |
| abstract: What would it mean to play a game that goes on forever? And how would we decide who wins such a game? What about questions like with perfect play, who wins this game? In this talk, we will make sure we understand the situation for finite games, and then go on to tackle infinite ones. |
| 20/02/2008 - 15:00 - Aula Seminari - Via Salaria 113 Rome, 3rd floor |
| Complete Minors in Huge Graphs |
| abstract: A classic theorem of Wagner completely characterizes graphs that cannot be contracted to K_5, the complete graph on five vertices. However, the structure of graphs which cannot be contracted to K_6 remains elusive. Jorgensen has conjectured that every 6-connected graph G either contains K_6 as a minor or there exists a vertex v in G such that G-v is a planar graph. In joint work with Matt DeVos, Rajneesh Hegde, Ken. Kawarabayashi, Serguei Norine, and Robin Thomas, we show that Jorgensen's conjecture is true with the additional assumption that the graph G is very large. The proof uses many of the tools and techniques of the Robertson Seymour graph minor series. We give a gentle introduction to these techniques before discussing how the methods relate to other problems on finding complete minors in a graph. |
| 31/01/2008 - 10:00 - Aula Alfa - Via Salaria, 113 |
| What's Ahead in Security? |
| abstract: Whitfield Diffie meets with Dipartimento di Informatica - Università di Roma 'La Sapienza' |
| 02/07/2007 - 15:00 - Aula Alfa, Via Salaria 113 DI |
| Specification of Domain Specific Visual Languages: From Single-View |
| abstract: Diagrammatic notations are pervasive in many engineering activities. In software engineering they are used in the planning, analysis and design phases as a means to specify, understand and reason about the system to be built. They range from general purpose languages (such as UML) to Domain Specific Visual Languages (DSVLs) oriented to a particular application domain. DSVLs provide high-level, powerful primitives, having the potential to increase the user productivity and result in higher-quality systems. DSVLs are at the core of recent software development paradigms, like Model Driven Development, where models are the primary asset from which code is generated. As systems become more complex, there is a need to split monolithic specifications into smaller, more comprehensible models, each describing an aspect of the system. Moreover, each characteristic can be described with a different notation. In this presentation, an overview of specification techniques for DSVL will be given, together with mechanisms for generating customized modelling environemnts for such languages. The specification takes into consideration syntax, semantics as well as interaction. In particular, the presentation will focus on meta-modelling and graph- transformation techniques for this purpose. Then, building on the concepts presented for (single-view) DSVLs, the presentation will move to the specification of Multi-View DSVLs, which are families of related notations (such as the UML) which can be used in combination. The presentation will address issues like specification of Multi-View DSVLs, syntactic consistency checking between different views, and semantic consistency. During the presentation, examples will be given with AToM3, a meta-modelling tool that implements these concepts. |
| 28/03/2007 - 16:00 - Aula Alfa - Dipartimento di Informatica - Via Salaria, 113 |
| ICT Transfer in Taiwan |
| abstract: The talk will describe the political situation of Taiwan, with particular reference to its relationship with China, and with the rest of the world. In this talk, will describe over current status of ICT industry and education. |
| 06/06/2006 - 9:00 - Roma |
| Privacy and Security |
| abstract: La sicurezza dei dati e delle reti in funzione del suo impatto sul sistema Paese, con particolare riferimento all’economia e alla sicurezza dei cittadini, è oramai diventata un tema centrale nel contesto della moderna Società dell’Informazione e della Comunicazione. In questo quadro si sono moltiplicate in tutto il mondo le iniziative mirate a stimolare attività di ricerca, sviluppo e innovazione nel campo della sicurezza informatica. Gli attori coinvolti in queste iniziative non sono solo le Accademie e gli istituti di ricerca ma anche soggetti privati e pubbliche amministrazioni interessate alla realizzazione di dispositivi e applicazioni che oltre ad innovare i processi produttivi tengano conto dei necessari requisiti di sicurezza. |
| 08/03/2006 - 14:30 - Aula Riunion Dip. Inf. |
| Termination Properties of Graph transformations |
| abstract: Abstract: Visual rewriting techniques, in particular graph transformations, are used increasingly to model transformations of systems specified through diagrammatic sentences. Although termination of graph rewriting is undecidable in general, there exist approaches, which exploit some form of control mechanisms for rewriting systems, such that termination can be proven for a restricted class of processes. In this lecture an overview of the current results in solving the termination problem for rewriting systems will be given. Moreover, some new work taking negative application conditions and inhibitors for non-deleting rules into account will be presented. This work was partially supported by the European Training and Mobility of Researches Network SegraVis. |
| 13/07/2005 - Aula Riunioni del Dipartimento di Informatica |
| Model transformation: application and theoretical issues. |
| abstract: Model transformation, of which refactoring constitutes an instance, is gaining importance in the software oriented community, especially with reference to the Model Driven Architecture, and the diffusion of software environment providing different tools for project management and evolution. Some fundamental problems arise as regards maintenance of consistent models under transformation, coherent updating of information distributed among models, specified with different languages, properties of the transformations, such as termination of chains of transformations. The seminar will give an overview of work going on in the Department on these themes, in connection with the Chair of software Engineering and in cooperation with two foreign visitors and one undergraduate student. Programme: Introduction, by Paolo Bottoni Rules and constraints, by Lars Schaps (University of Bremen) Keeping consistency among models, by Simone Pulcini Properties of transformations, by Kathrin Hoffmann (Technical University of Berlin). |
| 08/07/2005 - Aula Alfa, Dipartimento di Informatica |
| Recent Developments in MILS systems |
| abstract: Current commercial products and approaches to security do not meet the requirements for high-threat / high-value-asset environments. An emerging design paradigm for safety-critical and security-critical systems: Multiple Independent Levels of Security/Safety (MILS), based on high-assurance separation kernels and middleware currently under development by several vendors, will provide a modular, dependable, and certifiable basis for future high-assurance national security and critical infrastructure systems. We are developing a separation kernel to be certified at the highest levels of security and safety, designing high-assurance subsystems, and investigating an integrated formal development approach for MILS systems. The practical construction of MILS systems calls upon the collective advancements of recent years in the fields of hardware, computer security, avionics safety, software engineering, and formal methods, as well as highlighting the need for additional research. |
| 10/03/2005 - Aula Seminari, Dipartimento di Informatica |
| A Robust Watermarking System based on SVD |
| abstract: Speaker: Maria Calagna, PhD student Nowadays, digital images are widely distributed over the Internet. Due to the easy duplication and manipulation of these images, there is a great concern about protection of digital images. A new technology, digital watermarking, provides a promising way to protect digital images from illicit copy and manipulation. In this talk, a new image watermarking system based on the block-based SVD compression is introduced. Before watermark embedding, the cover image is divided into blocks and the SVD is applied to each block. To ensure the security of this scheme, more watermarks are embedded in the high-contrast regions and less in the low-contrast regions. The novelty of this watermarking scheme is to embed watermarks by making use of properties of block-based SVD compression. The watermark is embedded in all the singular values in the rank of each block according to the local features of the cover image so as to balance embedding capacity with distortion. The watermarking system is robust against typical attacks, including low-pass and high-pass filtering. In addition, our scheme is comparable to Cox's scheme regarding to robustness against the JPEG compression and the AWGN attacks, and is more robust against the histogram equalization, the intensity adjustment and the clipping attacks. |
| 09/07/2004 - Aula Alfa |
| George Fernandez (RMIT): "WebTutor: towards an automated e-tutor environment" |
| abstract: Teaching and learning by automatic generation and assessment of problems and quizzes for students to solve (called formative assessment in the research literature) has been used with significant success. However, the real challenge to support students' learning with an automated environment is to mimic what a human instructor would do when teaching: provide guided learning. To this end, we argue that at any stage of a student's learning session the automated system should take into account his/her demonstrated cognitive level and react accordingly, in this way challenging the students to make higher-level cognitive contributions as they progress through their learning. We say that an automated system that works by continuously generating and assessing a sequence of ever-increasing testing instruments implements adaptive learning by adaptive formative assessment. This seminar will present a possible framework for on-line, student-centred learning, and some initial considerations for the implementation of WebTutor, a prototype e-tutor environment in RMIT University based on this notion of adaptive learning. |
| 28/04/2004 - Dip. di Informatica - Aula Seminari |
| Power of communication in cooperative exploration of graphs |
| abstract: Speaker: Andrzej Pelc, Universite du Quebec en Outaouais, Gatineau, Canada We consider the task of exploring finite anonymous graphs by teams of mobile agents (modeled as finite automata) that have no a priori knowledge of the topology of the graph or of its size. Each edge has to be traversed by at least one agent. Information exchange between agents is crucial for performing such cooperative exploration. Our goal is to compare the strength of two communication scenarios from the point of view of feasibility of exploration: one is the local model in which agents can exchange information only when they meet at a node of the graph, and the other is the global model in which all agents can exchange all information available to them at each step of the exploration. We show that the global model is strictly stronger than the local model: there exists a family of graphs that cannot be explored by any finite team of agents in the local model but can be explored by just two agents in the global model. We also show that three agents are strictly stronger than two agents in the global model but no team of three agents can explore all graphs. |
