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We propose a new class of high-rate spatially coupled LDPC (SC-LDPC) codes based on the convolutional selforthogonal codes (CSOCs) first introduced by Massey. The SCLDPC codes are constructed by treating the irregular graph corresponding to the parity-check matrix of a systematic rate R=(n-1) / n CSOC as a convolutional protograph. The protograph can then be lifted using permutation matrices to ge
When the polar vortex meanders and shifts towards the equator, air masses from the tropics and subtropics can be transported towards the pole in so-called tropical-subtropical streamers. These large-scale structures are areas of low potential vorticity and high pressure, containing dry air with high ozone mixing ratios. The presence of these streamers can also be seen in changes in stratospheric o
Streaming applications are often described using dataflow actor models with a fixed network structure, allowing for static analysis and efficient hardware implementation. However, this fixed structure hinders scalability and design space exploration. This article investigates a representative dataflow toolchain, the StreamBlock compiler for the CAL actor language, along with its Actor Machine (AM)
2023 marks the year when the UIA World Congress Copenhagen event turns the Øresund Region into the epicenter of global debate on architecture’s capacity to reimagine the transformation of societies into sustainable living. Celebrating this manifestation, which will commence on both sides of the Sound, LAS23 will utilize the New European Bauhaus’ three concepts -- sustainability, aesthetics, inclus
Background noise makes listening effortful and may lead to fatigue. This may compromise classroom learning, especially for children with a non-native background. In the current study, we used pupillometry to investigate listening effort and fatigue during listening comprehension under typical (0 dB signal-to-noise ratio [SNR]) and favorable (+10 dB SNR) listening conditions in 63 Swedish primary s
We exhibit supercritical trade-off for monotone circuits, showing that there are functions computable by small circuits for which any small circuit must have depth superlinear or even super-polynomial in the number of variables, far exceeding the linear worst-case upper bound. We obtain similar trade-offs in proof complexity, where we establish the first size-depth trade-offs for cutting planes an
Gaseous ammonia, while influential in atmospheric processes, is critically underrepresented in atmospheric measurements. This limits our understanding of key climate-relevant processes, such as new particle formation, particularly in remote regions. Here, we present highly sensitive, online observations of gaseous ammonia from a coastal site in Antarctica, which allows us to constrain the mechanis
Annual Report LUND UNIVERSITY CENTRE FOR SUSTAINABILITY STUDIES (LUCSUS) | 2021 3LUCSUS ANNUAL REPORT 2021 Words from the Director Many activities took place in 2021 - from a distance. LUCSUS continued to develop sustainability in research and education. We continued to recruit new early career researchers and PhDs despite the continued Covid-19 situation. Staff continued to embrace and adapt to C
https://www.lucsus.lu.se/sites/lucsus.lu.se/files/2022-09/LUCSUS%20Annual%20report%202021.pdf - 2026-05-29
With the emergence of autonomous vehicles comes requirements on adequate and rigorous testing techniques, particularly as systems continuously adapt to changing environments. Scenario-based, simulated testing is one approach that has received attention, where deriving relevant scenarios from various sources is still a challenge. We therefore explore creating executable test scenarios from textual
Streaming applications, such as MPEG video encoders or sensor processing pipelines, are increasing in complexity as well as the diversity of platforms that they run on. The toolchains handling these applications must keep up with this increase at all levels of abstraction. The Actor Machine (AM) is an intermediate representation in the toolchain that we make use of. Large AMs are difficult to work
New particle formation (NPF) events substantially contribute to the number concentration of atmospheric particles and cloud condensation nuclei (CCN) which can further influence radiative balance and Earth's climate. Many short-term studies have found that sulfuric acid (H2 SO4) and highly oxygenated organic molecules (HOM) are critical compounds in the early steps of NPF. However, it is not fully
This article addresses the obstacle avoidance problem for setpoint stabilization tasks in complex dynamic 2-D environments that go beyond conventional scenes with isolated convex obstacles. A combined motion planner and controller is proposed that integrates the favorable convergence characteristics of closed-form motion planning techniques with the intuitive representation of system constraints t
Normalizing flows (NFs) have been shown to be advantageous in modeling complex distributions and improving sampling efficiency for unbiased sampling. In this work, we propose a new class of continuous NFs, ascent continuous normalizing flows (ACNFs), that makes a base distribution converge faster to a target distribution. As solving such a flow is non-trivial and barely possible, we propose a prac
Building on the progress in Boolean satisfiability (SAT) solving over the last decades, maximum satisfiability (MaxSAT) has become a viable approach for solving NP-hard optimization problems. However, ensuring correctness of MaxSAT solvers has remained a considerable concern. For SAT, this is largely a solved problem thanks to the use of proof logging, meaning that solvers emit machine-verifiable
Proof logging has long been the established method to certify correctness of Boolean satisfiability (SAT) solvers, but has only recently been introduced for SAT-based optimization (MaxSAT). The focus of this paper is solution-improving search (SIS), in which a SAT solver is iteratively queried for increasingly better solutions until an optimal one is found. A challenging aspect of modern SIS solve
Pseudo-Boolean proof logging has been used successfully to provide certificates of optimality from a variety of constraint- and satisifability-style solvers that combine reasoning with a backtracking or clause-learning search. Another paradigm, occurring in dynamic programming and decision diagram solving, instead reasons about partial states and possible transitions between them. We describe a fr
Modern subgraph-finding algorithm implementations consist of thousands of lines of highly optimized code, and this complexity raises questions about their trustworthiness. Recently, some state-of-the-art subgraph solvers have been enhanced to output machine-verifiable proofs that their results are correct. While this significantly improves reliability, it is not a fully satisfactory solution, sinc
One of the major open problems in complexity theory is proving super-logarithmiclower bounds on the depth of circuits (i.e., P⊈NC1). Karchmer et al. (Comput Complex 5(3/4):191–204, 1995) suggested to approach thisproblem by proving that depth complexity behaves “as expected”with respect to the composition of functions f◊g. They showedthat the validity of this conjecture would imply that P⊈NC1.Seve
Biological invasions are one of the leading causes of biodiversity loss worldwide. Given that eradication of invasive species is not usually a practical option, conservationists may attempt to limit their impacts through the designation and management of protected areas. Here, we investigate the effect of marine protected areas on the habitat suitability of an invasive species, the round goby (Neo
A non-adaptive quantitative group testing (GT) scheme based on sparse codes-on-graphs in combination with low-complexity peeling decoding was introduced and analyzed by Karimi et al.. In this work, we propose a variant of this scheme based on low-density parity-check codes where the BCH codes at the constraint nodes are replaced by simple single parity-check codes. Furthermore, we apply spatial co
