Opin vísindi
Opin vísindi er varðveislusafn vísindaefnis og doktorsritgerða í opnum aðgangi á vegum íslenskra háskóla og Landsbókasafns Íslands - Háskólabókasafns.
Opinn aðgangur að rannsóknaniðurstöðum er í samræmi við 10. gr. laga nr. 3/2003 um opinberan stuðning við vísindarannsóknir sem og kröfur innlendra og erlendra rannsóknasjóða. Markmiðið með opnum aðgangi er að niðurstöður rannsókna séu aðgengilegar sem flestum óhindrað og án endurgjalds á rafrænu formi. Vistun í varðveislusafninu er varanleg og ætlað að tryggja aðgang að vísindaefni íslenskra háskóla í opnum aðgangi um ókomna tíð. Varðveislusafnið Opin vísindi er tengt við rannsóknagáttina IRIS og rannsóknaniðurstöður í opnum aðgangi sem eru skráðar í IRIS eru um leið vistaðar og gerðar aðgengilegar til framtíðar í varðveislusafninu. Með því að safna þessu efni saman í eitt safn verður aðgangur að því einfaldur og þægilegur fyrir alla sem vilja kynna sér það og geta þannig notið þess öfluga vísindastarfs sem fram fer í háskólum landsins.
Varðveislusafnið er OpenAIRE / OpenAIREplus samhæft og samrýmist kröfum sem gerðar eru um birtingu rannsóknaniðurstaðna úr verkefnum sem styrkt eru úr evrópsku rannsóknaáætlununum FP7 og H2020.
Varðveislusafnið notar opna hugbúnaðinn DSpace.
Opinn aðgangur að rannsóknaniðurstöðum er í samræmi við 10. gr. laga nr. 3/2003 um opinberan stuðning við vísindarannsóknir sem og kröfur innlendra og erlendra rannsóknasjóða. Markmiðið með opnum aðgangi er að niðurstöður rannsókna séu aðgengilegar sem flestum óhindrað og án endurgjalds á rafrænu formi. Vistun í varðveislusafninu er varanleg og ætlað að tryggja aðgang að vísindaefni íslenskra háskóla í opnum aðgangi um ókomna tíð. Varðveislusafnið Opin vísindi er tengt við rannsóknagáttina IRIS og rannsóknaniðurstöður í opnum aðgangi sem eru skráðar í IRIS eru um leið vistaðar og gerðar aðgengilegar til framtíðar í varðveislusafninu. Með því að safna þessu efni saman í eitt safn verður aðgangur að því einfaldur og þægilegur fyrir alla sem vilja kynna sér það og geta þannig notið þess öfluga vísindastarfs sem fram fer í háskólum landsins.
Varðveislusafnið er OpenAIRE / OpenAIREplus samhæft og samrýmist kröfum sem gerðar eru um birtingu rannsóknaniðurstaðna úr verkefnum sem styrkt eru úr evrópsku rannsóknaáætlununum FP7 og H2020.
Varðveislusafnið notar opna hugbúnaðinn DSpace.
Nýlega bætt við
Clock Distribution with Gradient TRIX
(Association for Computing Machinery, 2025-06-13) Srinivas, Shreyas; Lenzen, Christoph; Department of Computer Science
Gradient clock synchronization (GCS) algorithms minimize the worst-case clock offset between the nodes in a distributed network of diameter D and size n. They achieve optimal offsets of ⊙(log D) locally, i.e., between adjacent nodes [14] and ⊙(D) globally [2]. A key open problem in this area is to achieve fault tolerance at minimal edge replication overhead.In this work, we achieve this goal under the assumption of an average-case distribution of faults, i.e., nodes fail with independent probability p ϵ o(n-1/2). In more detail, we present a self-stabilizing GCS algorithm for a grid-like directed graph with in- and out-degrees of 3. Note that even for tolerating a single fault, this degree is necessary, and if p was larger, it would not hold with probability 1 - o (1) that each node has at most one faulty in-neighbor. Our algorithm achieves asymptotically optimal local skew of ⊙(log D) with probability 1 - o(1); this holds under general worst-case assumptions on link delay and clock speed variations, provided they change slowly relative to the speed of the system.On the one hand, our results are of practical interest. As we discuss, the fault model is suitable for synchronously clocked hardware. Since our algorithm can simultaneously sustain a constant number of arbitrary changes due to faults in each clock cycle, it achieves sufficient robustness to dramatically increase the size of synchronously clocked systems.On the other hand, our results are of a theoretical interest. We show that for a worst-case distribution of f faulty nodes within our fault model's locality constraints, our algorithm achieves local skew O(5f log D). With probabilistically distributed faults, this becomes O(log D). Moreover, our work opens up avenues for further investigation of fault-tolerant synchronization, in particular trade-offs between fault distribution and edge density.
The Case of the Curious Robot : On the Social Viability of Curious Behavior in Non-Human Agents
(Association for Computing Machinery, Inc, 2024-12-26) Weatherwax, Kevin; Dooley, Doug; Carstensdottir, Elin; Takayama, Leila; Department of Computer Science
Curiosity is increasingly being looked at to develop interactive nonhuman agents capable of lifelong learning, particularly in the space of Ai driven agents. However, the way a non-human agent’s mental state is described could prime expectations in human counterparts as well as alter perceptions of an agent’s behavior. We conducted an online experiment examining people’s perceptions of four levels of curious behavior portrayed by a robot agent and whether this behavior matched people’s expectations when primed to anticipate a “curious” vs. “learning” vs. “autonomous” robot agent. As curiosity increased, the ratings of the robot agent’s thinking ability also increased. This was juxtaposed by a decrease in the robot’s ratings as an effective worker and social agent. Further, we captured a unique trajectory of expectation matching showing that agents’ internal mental states should be matched with analogous external behaviors. Our findings have implications for the design and development of non-human agents that engage in learning modeled on forms of human cognition.
GRandLine : Adaptively Secure DKG and Randomness Beacon with (Log-)Quadratic Communication Complexity
(Association for Computing Machinery, Inc, 2024-12-09) Bacho, Renas; Lenzen, Christoph; Loss, Julian; Ochsenreither, Simon; Papachristoudis, Dimitrios; Department of Computer Science
A randomness beacon is a source of continuous and publicly verifiable randomness which is of crucial importance for many applications. Existing works on randomness beacons suffer from at least one of the following drawbacks: (i) security only against static (i.e., non-adaptive) adversaries, (ii) each epoch takes many rounds of communication, or (iii) computationally expensive tools such as proof-of-work (PoW) or verifiable delay functions (VDF). In this work, we introduce GRandLine, the first adaptively secure randomness beacon protocol that overcomes all these limitations while preserving simplicity and optimal resilience in the synchronous network setting. We achieve our result in two steps. First, we design a novel distributed key generation (DKG) protocol GRand that runs in O(?n2 logn) bits of communication but, unlike most conventional DKG protocols, outputs both secret and public keys as group elements. Here, ? denotes the security parameter. Second, following termination of GRand, parties can use their keys to derive a sequence of randomness beacon values, where each random value costs only a single asynchronous round and O(?n2) bits of communication. We implement GRandLine and evaluate it using a network of up to 64 parties running in geographically distributed AWS instances. Our evaluation shows that GRandLine can produce about 2 beacon outputs per second in a network of 64 parties. We compare our protocol to the state-of-the-art randomness beacon protocols OptRand (NDSS ‘23), BRandPiper (CCS ‘21), and Drand, in the same setting and observe that it vastly outperforms them.
Together in the Mikrokosmos : Exploring Disabled Embodied Experiences in Designed Sociotechnical Worlds
(2024-11-08) Ringland, Kathryn E.; Carstensdottir, Elin; Tung, Matthew; Seetharaman, Bhavani; Eagle, Tessa; Baltaxe-Admony, Leya Breanna; Weatherwax, Kevin; Department of Computer Science
For geographically dispersed communities, including professional, academic, hobbyist, and fandom communities, in-person events and meetups play a crucial role in the function and health of the whole community. Building off prior literature, we take a nuanced look at large scale community events that blend online and offline interactions across digital and physical embodied experiences in order to build understanding of how this knowledge can be leveraged to build more accessible hybrid modalities for community events. Building on this foundation, this paper presents a comprehensive study using ethnographic methods to examine large scale community events, specifically stadium music concerts of varying modalities (e.g., in-person, live-streamed). Using a disability lens, we explore how such community events are experienced and technologically mediated, as well as how the community and individuals design and construct their own sociotechnical worlds across multiple modalities and embodied experiences. By centering the disabled embodied experience, we examine how community members navigate the concert environment, time, and the social experience of concert attendance. Based on our findings, we highlight the nuanced complexities of inclusive community-centered large scale, multi-modal events.
Stability Analysis of Switched Linear Systems via Numeric Computations of Continuous Piecewise Affine and Continuous Piecewise Quadratic Lyapunov Functions
(University of Iceland, School of Engineering and Natural Sciences, Faculty of Physical Sciences, 2026-11-20) Andersen, Stefania; Sigurður Hafstein; Faculty of Physical Sciences (UI); Raunvísindadeild (HÍ); School of Engineering and Natural Sciences (UI); Verkfræði- og náttúruvísindasvið (HÍ)
In this dissertation we present numerical methods for computing continuous piecewise affine (CPA) and continuous piecewise quadratic (CPQ) Lyapunov functions via linear programming (LP) for switched linear systems. We discuss the application of these methods to both arbitrary switching signals and signals subject to average dwell-time (ADT) constraints. Further, we discuss the challenges of computing the minimum average dwell-time (MADT) and present a search algorithm for its computation. Finally, we discuss our approach to computing CPQ functions via LP, rather than semidefinite programming (SDP).
Flokkar í Opnum vísindum
Veldu flokk til að skoða.
- University of Iceland
- University of Akureyri
- Bifröst University
- Hólar University College
- IRIS
- Agricultural University of Iceland
- National and University Library of Iceland
- Iceland University of the Arts