Raising the Achievement of all Learners in Inclusive Education Project: Rosmini and Sereni

Scientific Conference (2016, December)

Global converegence properties of a consensus protocol on the n-sphere

in Proceedings of the 55th IEEE Conference on Decision and Control (2016, December)

This paper provides a novel analysis of the global convergence properties of a well-known consensus protocol for multi-agent systems that evolve in continuous time on the n-sphere. The feedback is ... [more ▼]

This paper provides a novel analysis of the global convergence properties of a well-known consensus protocol for multi-agent systems that evolve in continuous time on the n-sphere. The feedback is intrinsic to the n-sphere, i.e., it does not rely on the use of local coordinates obtained through a parametrization. It is shown that, for any connected undirected graph topology and all n>1, the consensus protocol yields convergence that is akin to almost global consensus in a weak sense. Simulation results suggest that actual almost global consensus holds. This result is of interest in the context of consensus on Riemannian manifolds since it differs from what is known with regard to the 1-sphere and SO(3) where more advanced intrinsic consensus protocols are required in order to generate equivalent results. [less ▲]

An Empirical Analysis of Vulnerabilities in OpenSSL and the Linux Kernel

in 2016 Asia-Pacific Software Engineering Conference (APSEC) (2016, December)

Vulnerabilities are one of the main concerns faced by practitioners when working with security critical applications. Unfortunately, developers and security teams, even experienced ones, fail to identify ... [more ▼]

Vulnerabilities are one of the main concerns faced by practitioners when working with security critical applications. Unfortunately, developers and security teams, even experienced ones, fail to identify many of them with severe consequences. Vulnerabilities are hard to discover since they appear in various forms, caused by many different issues and their identification requires an attacker’s mindset. In this paper, we aim at increasing the understanding of vulnerabilities by investigating their characteristics on two major open-source software systems, i.e., the Linux kernel and OpenSSL. In particular, we seek to analyse and build a profile for vulnerable code, which can ultimately help researchers in building automated approaches like vulnerability prediction models. Thus, we examine the location, criticality and category of vulnerable code along with its relation with software metrics. To do so, we collect more than 2,200 vulnerable files accounting for 863 vulnerabilities and compute more than 35 software metrics. Our results indicate that while 9 Common Weakness Enumeration (CWE) types of vulnerabilities are prevalent, only 3 of them are critical in OpenSSL and 2 of them in the Linux kernel. They also indicate that different types of vulnerabilities have different characteristics, i.e., metric profiles, and that vulnerabilities of the same type have different profiles in the two projects we examined. We also found that the file structure of the projects can provide useful information related to the vulnerabilities. Overall, our results demonstrate the need for making project specific approaches that focus on specific types of vulnerabilities. [less ▲]

Discrete Pompeiu problem on the plain

Presentation (2016, December)

Sociability-Driven User Recruitment in Mobile Crowdsensing Internet of Things Platforms

in IEEE Global Communications Conference (GLOBECOM), Washington, DC, USA, 2016 (2016, December)

The Internet of Things (IoT) paradigm makes the Internet more pervasive, interconnecting objects of everyday life, and is a promising solution for the development of next- generation services. Smart ... [more ▼]

The Internet of Things (IoT) paradigm makes the Internet more pervasive, interconnecting objects of everyday life, and is a promising solution for the development of next- generation services. Smart cities exploit the most advanced information technologies to improve and add value to existing public services. Applying the IoT paradigm to smart cities is fundamental to build sustainable Information and Communication Technology (ICT) platforms. Having citizens involved in the process through mobile crowdsensing (MCS) techniques unleashes potential benefits as MCS augments the capabilities of the platform without additional costs. Recruitment of participants is a key challenge when MCS systems assign sensing tasks to the users. Proper recruitment both minimizes the cost and maximizes the return, such as the number and the accuracy of accomplished tasks. In this paper, we propose a novel user recruitment policy for data acquisition in mobile crowdsensing systems. The policy can be employed in two modes, namely sociability-driven mode and distance-based mode. Sociability stands for the willingness of users in contributing to sensing tasks. Furthermore, we propose a novel metric to assess the efficiency of any recruitment policy in terms of the number of users contacted and the ones actually recruited. Performance evaluation, conducted in a real urban environment for a large number of participants, reveals the effectiveness of sociability-driven user recruitment as the average number of recruited users improves by at least a factor of two. [less ▲]

Norms, Polycentricity, and Polylanguaging on Social Media

in Duncker, Dorthe; Perregaard, Bettina (Eds.) Creativity and Continuity: Perspectives on the Dynamics of Language Conventionalisation (2016)

This contribution examines adolescent language use, interaction, and acts of identification on social media sites. Our approach is sociolinguistic, and we show how the understanding of language users ... [more ▼]

This contribution examines adolescent language use, interaction, and acts of identification on social media sites. Our approach is sociolinguistic, and we show how the understanding of language users today needs to break free from previously well-established sociolinguistic notions such as languages as countable units. In the following we argue that hybridity in language use is not intrinsically deviant, that language users may have multiple belongings and identifications, and that linguistic ideology must be accounted for by researchers. We also demonstrate how notions such as registers, polycentricity, and (poly)languaging enable us to address the relationships between language users, language form, social goals, and normativity. The data come from three linguistically heterogeneous European settings, and all focus on hybridity and ethnicity. [less ▲]

The influence of superposition and eccentric loading on the bearing capacity of shallow foundations

in Computations and Materials in Civil Engineering (2016), 1(3), 121-131

In 1920 Prandtl published an analytical solution for the bearing capacity of a centric loaded strip footing on a weightless in-finite half-space. Reissner (1924) extended this solution for a surrounding ... [more ▼]

In 1920 Prandtl published an analytical solution for the bearing capacity of a centric loaded strip footing on a weightless in-finite half-space. Reissner (1924) extended this solution for a surrounding surcharge and Keverling Buisman (1940) for the soil weight. Terzaghi (1943) wrote this as a superposition of three separate bearing capacity components for the cohesion, surcharge and soil-weight. The first question is to what ex-tent the currently used components are correct. The second question is to what extent the superposition is correct, because the failure mechanisms for these three components are not the same. A number of finite element calculations show that there is indeed an error, which is luckily not too large and leads to predictions on the safe side. Meyerhof (1953) extended the equation of Terzaghi with correction factors for the shape of the footing and the inclination of the load. For eccentric loading however, there are no correction factors. The common practice is to reduce the contact area of the foundation such that its centroid coincides with that of the load, which means that, the area of the foundation outside the effective area, is completely neglected. Therefore the third question is, if this reduction of the foundation area is an accurate method to describe the reduction of the bearing capacity due to eccentric loading. A number of finite element calculations show that this is indeed the case. [less ▲]

A three-dimensional movement analysis of the spike in fistball

in Sports (2016), 4(4), 1-12

Due to its relevancy to point scoring, the spike is considered as one of the most important skills in fistball. Biomechanical analyses of this sport are very rare. In the present study, we performed a ... [more ▼]

Due to its relevancy to point scoring, the spike is considered as one of the most important skills in fistball. Biomechanical analyses of this sport are very rare. In the present study, we performed a three-dimensional kinematic analysis of the fistball spike, which helps to specify performance parameters on a descriptive level. Recorded by four synchronized cameras (120 Hz) and linked to the motion capture software Simi Motion® 5.0, three female fistball players of the second German league (24–26 years, 1.63–1.69 m) performed several spikes under standardized conditions. Results show that the segment velocities of the arm reached their maximum successively from proximal to distal, following the principle of temporal coordination of single impulses. The wrist shows maximum speed when the fist hits the ball. The elbow joint angle performs a rapid transition from a strong flexion to a (almost) full extension; however, the extension is completed after the moment of ball impact. In contrast, the shoulder joint angle increases almost linearly until the fistball contact and decreases afterward. The findings can be used to optimize the training of the spike. [less ▲]

Towards Integration on Colored Supermanifolds

in Banach Center Publications (2016, December), 110

The European Association for Data Science, its main goals and tasks

Presentation (2016, December)