Search results for "SAND"
showing 10 items of 2366 documents
Recursive and bargaining values
2021
Abstract We introduce two families of values for TU-games: the recursive and bargaining values. Bargaining values are obtained as the equilibrium payoffs of the symmetric non-cooperative bargaining game proposed by Hart and Mas-Colell (1996). We show that bargaining values have a recursive structure in their definition, and we call this property recursiveness. All efficient, linear, and symmetric values that satisfy recursiveness are called recursive values. We generalize the notions of potential, and balanced contributions property, to characterize the family of recursive values. Finally, we show that if a time discount factor is considered in the bargaining model, every bargaining value h…
Cryptanalysis of Knapsack Cipher Using Ant Colony Optimization
2018
Ant Colony Optimization is a search metaheuristic inspired by the behavior of real ant colonies and shown their effectiveness, robustness to solve a wide variety of complex problems. In this paper, we present a novel Ant Colony Optimization (ACO) based attack for cryptanalysis of knapsack cipher algorithm. A Cipher-text only attack is used to discover the plaintext from the cipher-text. Moreover, our approach allows us to break knapsack cryptosystem in a minimum search space when compared with other techniques. Experimental results prove that ACO can be used as an effective tool to attack knapsack cipher.
An abstract inf-sup problem inspired by limit analysis in perfect plasticity and related applications
2021
This paper is concerned with an abstract inf-sup problem generated by a bilinear Lagrangian and convex constraints. We study the conditions that guarantee no gap between the inf-sup and related sup-inf problems. The key assumption introduced in the paper generalizes the well-known Babuška–Brezzi condition. It is based on an inf-sup condition defined for convex cones in function spaces. We also apply a regularization method convenient for solving the inf-sup problem and derive a computable majorant of the critical (inf-sup) value, which can be used in a posteriori error analysis of numerical results. Results obtained for the abstract problem are applied to continuum mechanics. In particular…
UnipaBCI a novel general software framework for brain computer interface
2017
The increasing interest in Brain Computer Interface (BCI) requires new fast, reliable and scalable frameworks that can be used by researchers to develop BCI based high performance applications in efficient and fast ways. In this paper is presented "UnipaBCI", a general software framework for BCI applications based on electroencephalogra-phy (EEG) that can fulfill these new needs. A visual evoked potentials (VEP) application has also been developed using the proposed framework in order to test the modular architecture and the overall performance. Different types of users (beginners and experts in BCI) have been involved during the "UnipaBCI" experimental test and they have exhibited good and…
Learning paths on elementary university courses in Finnish as a second language
2015
Along with the growing degree of internationalisation, Finnish university education needs to address issues related to learning and teaching Finnish as a second language. From the perspective of teaching Finnish and related pedagogical development, it is essential to recognise when, where and for which purposes learners need Finnish at the various stages of the language acquisition process. This article focuses on the learning paths of three international students who studied Finnish on a one-term elementary course at the University of Jyvaskyla Language Centre. The article is based on a socio-cultural and ecological view on language learning and teaching. The data consist of learning diary…
”CodeInnova”: A Unified Framework for Teaching Programming and Computational Thinking In Primary Schools
2021
Teaching programming and computational thinking (CT) in primary schools have become more common in the last decade. However, there has been little international consensus on what teaching the topics encompass. We present CodeInnova, a framework developed jointly between four partnering countries for teaching programming and CT in K–9. In this paper, we present the curriculum for teaching CT and the accompanying teaching materials developed in CodeInnova. We also discuss preliminary results of testing the developed resources in classrooms.
An Exploration of Issues and Challenges Faced by Students in Distance Learning Environment
2019
This paper investigates the issues and challenges encountered by students obtaining distance education in Pakistan. We conducted interviews with students obtaining distance education and they were enrolled in different study programs. Qualitative interviews were conducted to understand the perception of the study participants regarding the issues and challenges faced by them in learning. Students from five distance learning programs were selected and five participants from each study program were interviewed in this study. The findings reveal that distance learning students encounter impediment in their learning due to their personal circumstances, teachers’ related issues, and due to asses…
Perspectives and reflections on teaching linear algebra
2020
Abstract This paper presents ‘expert opinions’ on what should be taught in a first-year linear algebra course at university; the aim is to gain a generic picture and general guiding principles for such a course. Drawing on a Delphi method, 14 university professors—called ‘experts’ in this study—addressed the following questions: What should be on a first-year linear algebra undergraduate course for engineering and/or mathematics students? How could such courses be taught? What tools (if any) are essential to these two groups of students? The results of the investigation, these experts’ opinions, mainly concern what should be in a linear algebra course (e.g. problem-solving and applications)…
The cone of gaze
2011
Gaze direction is an important cue that regulates social interactions. Although humans are very accurate in determining gaze directions in general, they have a surprisingly liberal criterion for the presence of mutual gaze. We first established a psychophysical task to measure the cone of gaze, which required observers to adjust the eyes of a virtual head to the margins of the area of mutual gaze. Then we examined differences between 2D, 3D, and genuine real life gaze. Finally, the tolerance for image distortions when the virtual head is not viewed from the proper vantage point was investigated. Gaze direction was remarkably robust toward loss in detail and distortion. Important lessons for…
Comparing Tangible and Fully Virtual Haptic Systems for HMI Studies in Simulated Driving Situations
2019
International audience; The contribution of tangible and intangible feedback is compared for virtual tactile car Human-Machine Interfaces (HMI) design, to measure their performance both in static conditions and while driving. A subjectively calibrated transparent glass provides tangible passive haptics, and visual cues are used to study sensory substitution-based intangible interactions. The results show that the performance of the subjects was significantly improved in driving conditions as they interacted faster, more accurately and with a higher satisfaction. In addition, our findings highlight that the contribution of tangible systems is significantly lower in driving conditions, raisin…