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A piezoelectric micro mass flow controller (MMFC) for liquid fuel injection into a mini-HCCI-motor for power generation is introduced. Piezoelectric actuation ensures negligible power consumption for fuel injection allowing self-sustaining operation. A pressurized fuel tank is connected to the MMFC which is designed like a normally-closed, on-/off-operating valve. Integrated piezoresistors are use
This work has focused on studying the in-cylinder pressure fluctuations caused by rapid HCCI combustion and determine what they consist of. Inhomogeneous autoignition sets up pressure waves traversing the combustion chamber. These pressure waves induce high gas velocities which causes increased heat transfer to the walls or in worst case engine damage. In order to study the pressure fluctuations a
Response time is a measure of quality of service in com- puter systems. Estimation techniques, suitable for support systems for mobile phone systems, are explored. These sys- tems are complex queueing systems with large databases. The trac generated by users and system adminstrators changes rapidly, some loads can be measured other cannot. Attempts to capture all details give models that are not s
The anesthetic drug propofol is commonly used to control hypnotic depth (suppression of awareness) in patients undergoing surgery or intensive care. In addition to manual titration, a model-based open-loop feed-forward strategy called target-controlled infusion (TCI) has attained some clinical popularity. Research on closed-loop control, with awareness estimates derived from an electroencephalogra
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
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
Hur går det till när besluts fattas om huruvida, när och vart ett barn eller en ungdom ska placeras i samhällsvård och vad händer med detta beslutsfattande när ärendetrycket ökar på organisationen? Den brittiske barnavårdsforskaren Nigel Parton (1998), bland andra, har hävdat att när trycket ökar och resurser blir färre inom människobehandlande organisationer som Socialtjänsten, är en vanlig reakt
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)
In the last column, we promised to return to one of the inevitable challenges that vibe coding leaves us with. At the AI Engineer World’s Fair 2025, OpenAI’s Sean Grove claimed that whoever writes the specification is now the programmer since AI can take it from there. Sounds amazing, but what gets lost along the way? To explore this, I’m joined by Jan-Philipp Steghöfer, a researcher at XITASO and
Reconfigurable scan networks (RSNs) provide efficient and flexible access to on-chip logic, such as instruments for test and diagnostics, throughout a semiconductor’s lifetime. Test instruments are powerful, as they provide high controllability and observability. The availability of a high number of test instruments, as well as the standardized and easy access, makes RSNs a valuable target for an
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
The hardware accelerated ray-tracing pipeline presents many opportunities to implement more advanced rendering algorithms than earlier rasterization based approaches. However, one particular aspect of the pipeline still remains a bit too costly to use in practice: The AnyHit-shader. Opacity Micromaps were introduced to alleviate this issue, but the central problem of calling arbitrary shader code
We show that a generalization of the DAG-like query-to-communication lifting theorem, when proven using sunflowers over non-binary alphabets, yields lower bounds on the monotone circuit complexity and proof complexity of natural functions and formulas that are better than previously known results obtained using the approximation method. These include an nΩ(k) lower bound for the clique function up
A proof system P is said to be automatable in time f(N) if there exists an algorithm that given as input an unsatisfiable formula F outputs a refutation of F in the proof system P in time f(N), where N is the size of the smallest P-refutation of F plus the size of F. Atserias and Bonet (ECCC 2002), observed that tree-like k-DNF resolution is automatable in time Nc·k log N for a universal constant
