From Flow Logic to static type systems for coordination languages

Coordination languages are often used to describe open-ended systems. This makes it challenging to develop tools for guaranteeing the security of the coordinated systems and the correctness of their interaction. Successful approaches to this problem have been based on type systems with dynamic checks; therefore, the correctness properties cannot be statically enforced. By contrast, static analysis approaches based on Flow Logic usually guarantee properties statically. In this paper, we show how the insights from the Flow Logic approach can be used to construct a type system for statically ensuring secure access to tuple spaces and safe process migration for an extension of the language Klaim.     

Exploration strategies based on multi-criteria decision making for searching environments in rescue operations

Some applications require autonomous robots to search an initially unknown environment for static targets, without any a priori information about environment structure and target locations. Targets can be human victims in search and rescue or materials in foraging. In these scenarios, the environment is incrementally discovered by the robots exploiting exploration strategies to move around in an autonomous and effective way. Most of the strategies proposed in literature are based on the idea of evaluating a number of candidate locations on the frontier between the known and the unknown portions of the environment according to ad hoc utility functions that combine different criteria. In this paper, we show some of the advantages of using a more theoretically-grounded approach, based on Multi-Criteria Decision Making (MCDM), to define exploration strategies for robots employed in search and rescue applications. We implemented some MCDM-based exploration strategies within an existing robot controller and we evaluated their performance in a simulated environment.     

Reliable regulation in centralized control systems

This paper addresses the design of a reliable control system for a linear, asymptotically stable plant. Specifically, the considered problem consists in finding a regulator which guarantees asymptotic stability, signal tracking and disturbance rejection when all the instrumentation is operational, and ensures that these properties are preserved, to the maximum possible extent, when an arbitrary number of sensors and/or actuators faults occur, that is, some of the feedback loops open. With reference to a centralized control structure and exogenous signals with multiple poles on the imaginary axis, the paper supplies a necessary and sufficient condition for the problem to admit a solution, and a possible least order regulator.     

Low-complexity FFT/IFFT IP hardware macrocells for OFDM and MIMO–OFDM CMOS transceivers

The paper presents an automated environment for fast design space exploration and automatic generation of FFT/IFFT macrocells with minimum circuit and memory complexity within the numerical accuracy budget of the target application. The effectiveness of the tool is demonstrated through FPGA and CMOS implementations (90 nm, 65 nm and 45 nm technologies) of the baseband processing in embedded OFDM transceivers. Compared with state-of-art FFT/IFFT IP cores, the proposed work provides macrocells with lower circuit complexity while keeping the same system performance (throughput, transform size and accuracy) and is the first addressing the requirements of all OFDM standards including MIMO systems: 802.11 WLAN, 802.16 WMAN, Digital Audio and Video Broadcasting in terrestrial, handheld and hybrid satellite-scenarios, Ultra Wide Band, Broadband on Power Lines, xDSL.     

The Internet’s impact on sexuality: A critical review of 15 years of research

The body of empirical research on Internet sexuality has grown steadily since 1993. The following paper provides an overview of the current state of research in this field in its full thematic breadth, addressing six areas of online sexuality: Pornography, sex shops, sex work, sex education, sex contacts, and sexual subcultures. Key research results are presented concerning Internet sexuality’s forms of manifestation, participant groups, opportunities, and risks. This paper shows that sexually related online activities have become routine in recent years for large segments of the population in the Western world. Internet sexuality also takes somewhat different forms based on the age, gender, and sexual orientation of the individual. Academic studies to date have focused overwhelmingly on the possible negative effects of Internet sexuality. By contrast, little research has been conducted on potential benefits. Consequently, a surprising number of gaps are evident in the scholarship on Internet sexuality.     

Enhancing augmented reality with cognitive and knowledge perspectives: a case study in museum exhibitions

ABSTRACT

In this paper, we present our results related to the definition of a methodology that combines augmented reality (AR) with semantic techniques for the creation of digital stories associated with museum exhibitions. In contrast to traditional AR approaches, we augment real-world elements by supplementing contents of a museum exhibition with additional inputs that provide new and different meanings. In this way we augment a cultural resource with respect to both its presentation and meaning. The methodology is framed in the cultural re-mediation theory and is grounded on a set of ontologies aimed at modelling a cultural resource and correlating it with external multimedia objects and resources. To provide an easy tool for the creation of museum narratives, the methodology makes use of a set of recognised practices widely adopted by museum curators that have been formalised through inference rules. The defined methodology has been experimented in a scenario related to Flemish paintings to validate the augmentation of cultural objects with two different approaches, the first basing on similarities and the second on dissimilarities.     

On the relation among answer set solvers

In this paper, we study the relation among Answer Set Programming (ASP) systems from a computational point of view. We consider smodels, dlv, and cmodels ASP systems based on stable model semantics, the first two being native ASP systems and the last being a SAT-based system. We first show that smodels, dlv, and cmodels explore search trees with the same branching nodes (assuming, of course, a same branching heuristic) on the class of tight logic programs. Leveraging on the fact that SAT-based systems rely on the deeply studied Davis–Logemann–Loveland (dll) algorithm, we derive new complexity results for the ASP procedures. We also show that on nontight programs the SAT-based systems are computationally different from native procedures, and the latter have computational advantages. Moreover, we show that native procedures can guarantee the “correctness” of a reported solution when reaching the leaves of the search trees (i.e., no stability check is needed), while this is not the case for SAT-based procedures on nontight programs. A similar advantage holds for dlv in comparison with smodels if the “well-founded” operator is disabled and only Fitting’s operator is used for negative inferences. We finally study the “cost” of achieving such advantages and comment on to what extent the results presented extend to other systems.     

Adaptive course generation through learning styles representation

This paper presents an approach to automatic course generation and student modeling. The method has been developed during the European funded projects Diogene and Intraserv, focused on the construction of an adaptive e-learning platform. The aim of the platform is the automatic generation and personalization of courses, taking into account pedagogical knowledge on the didactic domain as well as statistic information on both the student’s knowledge degree and learning preferences. Pedagogical information is described by means of an innovative methodology suitable for effective and efficient course generation and personalization. Moreover, statistic information can be collected and exploited by the system in order to better describe the student’s preferences and learning performances. Learning material is chosen by the system matching the student’s learning preferences with the learning material type, following a pedagogical approach suggested by Felder and Silverman. The paper discusses how automatic learning material personalization makes it possible to facilitate distance learning access to both able-bodied and disabled people. Results from the Diogene and Intraserv evaluation are reported and discussed.     

Design optimization of an enzymatic assay in an electrokinetically-driven microfluidic device

Microfluidic systems are increasingly popular for rapid and cheap determinations of enzyme assays and other biochemical analysis. In this study reduced order models (ROM) were developed for the optimization of enzymatic assays performed in a microchip. The model enzyme assay used was β-galactosidase (β-Gal) that catalyzes the conversion of Resorufin β-d-galactopyranoside (RBG) to a fluorescent product as previously reported by Hadd et al. (Anal Chem 69(17): 3407–3412, 1997). The assay was implemented in a microfluidic device as a continuous flow system controlled electrokinetically and with a fluorescence detection device. The results from ROM agreed well with both computational fluid dynamic (CFD) simulations and experimental values. While the CFD model allowed for assessment of local transport phenomena, the CPU time was significantly reduced by the ROM approach. The operational parameters of the assay were optimized using the validated ROM to significantly reduce the amount of reagents consumed and the total biochip assay time. After optimization the analysis time would be reduced from 20 to 5.25 min which would also resulted in 50% reduction in reagent consumption.