39 research outputs found
Polarized x-ray absorption spectra of CuGeO3 at the Cu and Ge K edges
Polarized x-ray absorption near edge structure (XANES) spectra at both the Cu
and the Ge K-edges of CuGeO3 are measured and calculated relying on the
real-space multiple-scattering formalism within a one-electron approach. The
polarization components are resolved not only in the unit cell coordinate
system but also in a local frame attached to the nearest neighborhood of the
photoabsorbing Cu atom. In that way, features which resist a particular
theoretical description can be identified. We have found that it is the
out-of-CuO4-plane p_{z'} component which defies the one-electron calculation
based on the muffin-tin potential. For the Ge K-edge XANES, the agreement
between the theory and the experiment appears to be better for those
polarization components which probe more compact local surroundings than for
those which probe regions with lower atomic density. Paper published in Phys.
Rev. B 66, 155119 (2002) and available on-line at
http://link.aps.org/abstract/PRB/v66/e155119.Comment: 15 pages, 6 figures. Published in Physical Review B, abstract
available on-line at http://link.aps.org/abstract/PRB/e15511
SAMo: experimenting a social accountability web platform
The need for transparency and quality control of public services is crucial for a sustainable development of underserved communities. Information and data collection play a significant role in the efforts that NGOs, governments and international institutions are carrying out in this direction. In this paper we describe a platform to conduct assessment campaigns of the quality of public services and its experimentation in the rural district of Moamba, Mozambique
Localized and itinerant character of electron states in the photoemission from CuGeO3
It is shown that electron correlation among Cu d-electrons explains the photoemission data of CuGeO3 and is responsible for the insulating behaviour and of the observed complex satellite structures. The analysis and interpretation of the experiments require the use of a multi-band Hamiltonian which explicitly includes both on site electron correlation and a detailed description of the single-particle band states
An Adaptive Learning with Gamification & Conversational UIs: The Rise of CiboPoliBot
Gamification in the era of chatbots is a novel way to engage users with the chatbot application. When developing a gamified chatbot system, there are factors related to user types (ages, gender and others) that we should consider to effectively integrate the game elements into the chatbot while targeting the right audience. In this study, we discuss the development of an educational chatbot game 'CiboPoli', that's specialised in teaching children about healthy lifestyle through an interactive social game environment. The presented game is based on a paper prototype that we developed to teach primary school students about healthy diet and food waste management. The current approach will be more engaging and pose AI capabilities. This is still a work in progress and we plan to improve its design by incorporating additional components, such as dialog management module, user-specific knowledge module or machine learning module. Future work will be devoted to integrating machine learning to automatically identify learners emotions and provide personalised suggestions. Moreover, we tested the initial prototype with school students and found that it outperforms the paper version. Future work will focus on applying it to other domains and demographics
Formal Specification and Analysis of an e-Voting System. In:
Abstract-Electronic voting systems are a perfect example of security-critical computing. One of the critical and complex parts of such systems is the voting process, which is responsible for correctly and securely storing intentions and actions of the voters. Unfortunately, recent studies revealed that various evoting systems show serious specification, design, and implementation flaws. The application of formal specification and verification can greatly help to better understand the system requirements of e-voting systems by thoroughly specifying and analyzing the underlying assumptions and the security specific properties. This paper presents the specification and verification of the electronic voting process for the Election Systems & Software (ES&S) system. We used the ASTRAL language to specify the voting process of ES&S machines and the critical security requirements for the system. Proof obligations that verify that the specified system meets the critical requirements were automatically generated by the ASTRAL Software Development Environment (SDE). The PVS interactive theorem prover was then used to apply the appropriate proof strategies and discharge the proof obligations
Specification of the Control Logic of an eVoting System in UML: the ProVotE experience
The ProVotE project aims at actuating art. 84 of law 2 - 5/3/2003 of the Autonomous Province of Trento (Italy), which promotes the introduction of e-voting systems for the next provincial elections. The goals of the project are building an e-voting system and defining the related process and certification issues in order to deliver a solution which is compliant with the italian electoral law, that is trusted and usable by the voters, and that implements the security and dependability requirements of the best international practices and experiences. This paper presents some of the issues and challenges we faced during the development of the e-voting prototype which was tested by about 8500 voters in three different trials held during the elections for the local representatives. In particular we show how we integrated UML in the development process of the e-voting machine. We also highlight how we extended existing tools to support the formal verification of the UML specifications and how we automated the generation of a critical component of the e-voting machine using UML statecharts
Maputo Living Lab Summer School of ICTs: An Experience Report
This paper presents our experience with the organization of the Summer School of ICTs (SSICT) of Maputo Living Lab. SSICT is a free 1-month course for 3rd and 4th year undergraduate students that provides practical training on the management, design and development of software projects that can have an impact on the local society. The School has been organized for 2 editions in 2011 and 2012 in Maputo, Mozambique and it is part of the larger Maputo Living Lab project
Formal Specification and Verification of an e-voting System: An experience Report.
We have seen that several currently deployed e-voting systems share critical failures in their design and implementation, which
render their technical and procedural controls insuļ¬cient to guarantee trustworthy voting. The application of formal methods
would greatly help to better address problems associated with assurance against requirements and standards. More speciļ¬cally, it
would help to thoroughly specify and analyze the underlying assumptions and security speciļ¬c properties, and it would improve the
trustworthiness of the ļ¬nal systems. In this article, we show how such techniques can be used to model and reason about the security
of one of the currently deployed e-voting systems in the USA named ES&S. We used the ASTRAL language to specify the voting
process of ES&S machines and the critical security requirements for the system. Proof obligations that verify that the speciļ¬ed
system meets the critical requirements were automatically generated by the ASTRAL Software Development Environment (SDE).
The PVS interactive theorem prover was then used to apply the appropriate proof strategies and discharge the proof obligations.
We also believe that besides analyzing the system against its requirements, it is equally important to perform an analysis under
malicious circumstances where the execution model is augmented with attack behaviors. Thus, we extend the formal speciļ¬cation
of the system by specifying attacks that have been shown to successfully compromise the system, and we then repeat the formal
veriļ¬cation. This is helpful in detecting missing requirements or unwarranted assumptions about the speciļ¬cation of the system.
In addition, this allows one to sketch countermeasure strategies to be used when the system behaves diļ¬erently than it should and
to build conļ¬dence about the system under development. Finally, we acknowledge the main problem that arises in e-voting system
speciļ¬cation and veriļ¬cation: modeling attacks is very diļ¬cult because the diļ¬erent types of attack often cut across the structure
of the original behavior models, thus making (incremental or compositional) veriļ¬cation very diļ¬cult