Abstract Response-Time Analysis: A Formal Foundation for the Busy-Window Principle (Artifact)

This artifact provides the means to validate and reproduce the results of the associated paper "Abstract Response-Time Analysis: A Formal Foundation for the Busy-Window Principle". In this artifact we demonstrate how to compile the source code and automatically check the proofs of each theorem. We also provide references to all key results claimed to be proven in the paper (including Abstract RTA and all eight instantiations), so that readers may confirm that no proofs have been omitted

Abstract Response-Time Analysis: A Formal Foundation for the Busy-Window Principle

This paper introduces the first general and rigorous formalization of the classic busy-window principle for uniprocessors. The essence of the principle is identified as a minimal set of generic, high-level hypotheses that allow for a unified and general abstract response-time analysis, which is independent of specific scheduling policies, workload models, and preemption policy details. From this abstract core, the paper shows how to obtain concrete analysis instantiations for specific uniprocessor schedulers via a sequence of refinement steps, and provides formally verified response-time bounds for eight common schedulers and workloads, including the widely used fixed-priority (FP) and earliest-deadline first (EDF) scheduling policies in the context of fully, limited-, and non-preemptive sporadic tasks. All definitions and proofs in this paper have been mechanized and verified with the Coq proof assistant, and in fact form the common core and foundation for verified response-time analyses in the Prosa open-source framework for formally proven schedulability analyses

Results of determining the agrotechnical indicators of a flat cutter for fine tillage

In modern conditions, most soils are exposed to erosion processes. In this regard, it is necessary to control the amount of dust particles in the surface layer of the soil. Fine tillage with flat-cutting working bodies solves this issue by creating a finely cloddy soil structure of the upper fertile layer. The article considers the developed original design of a flat cutter for fine tillage. The results of experimental studies on the determination of agrotechnical indicators for the treated background and untreated stubble background are presented. In the course of the research, such indicators were established as: the average actual working depth, the standard deviation of the working depth from the given one, the coefficient of variation in the working depth, crumbling of the soil by the working bodies, the moisture content inside the reservoir, the number of erosion-dangerous particles in the surface soil layer. As a result of the research, it was found that the flat cutter qualitatively performs the specified depth of tillage with an acceptable deviation, the ridge size is in the range of 3.6-3.9 cm, which is allowed by agrotechnical requirements, the number of lumps up to 25 mm in size after the passage of the working body is 82-85% . With shallow tillage with a flat cutter, the removal of wet layers to the soil surface is not observed. The flat cutter can function qualitatively on an untreated stubble background as part of a combined unit that is not equipped with disk working bodies

Oxidation of Nb(110): atomic structure of the NbO layer and its influence on further oxidation.

NbO terminated Nb(110) and its oxidation are examined by scanning tunneling microscopy and spectroscopy (STS). The oxide structures are strongly influenced by the structural and electronic properties of the underlying NbO substrate. The NbO is terminated by one-dimensional few-nanometer nanocrystals, which form an ordered pattern. High-resolution STS measurements reveal that the nanocrystals and the regions between the nanocrystals exhibit different electronic characters. Low-dosage oxidation, sufficient for sub-monolayer coverage of the NbO, with subsequent UHV annealing results in the formation of resolved sub-nanometer clusters, positioned in-between the nanocrystals. Higher dosage oxidation results in the formation of a closed Nb2O5-y layer, which is confirmed by X-ray photoelectron spectroscopy measurements. The pentoxide is amorphous at the atomic-scale. However, large scale (tens of nanometers) structures are observed with their symmetry matching that of the underlying nanocrystals

Step bunching with both directions of the current: Vicinal W(110) surfaces versus atomistic scale model

We report for the first time the observation of bunching of monoatomic steps on vicinal W(110) surfaces induced by step up or step down currents across the steps. Measurements reveal that the size scaling exponent {\gamma}, connecting the maximal slope of a bunch with its height, differs depending on the current direction. We provide a numerical perspective by using an atomistic scale model with a conserved surface flux to mimic experimental conditions, and also for the first time show that there is an interval of parameters in which the vicinal surface is unstable against step bunching for both directions of the adatom drift.Comment: 17 pages, 10 figure

Strong magnon-photon coupling with chip-integrated YIG in the zero-temperature limit

The cross-integration of spin-wave and superconducting technologies is a promising method for creating novel hybrid devices for future information processing technologies to store, manipulate, or convert data in both classical and quantum regimes. Hybrid magnon-polariton systems have been widely studied using bulk Yttrium Iron Garnet (Y$_{3}$Fe$_{5}$O$_{12}$, YIG) and three-dimensional microwave photon cavities. However, limitations in YIG growth have thus far prevented its incorporation into CMOS compatible technology such as high quality factor superconducting quantum technology. To overcome this impediment, we have used Plasma Focused Ion Beam (PFIB) technology -- taking advantage of precision placement down to the micron-scale -- to integrate YIG with superconducting microwave devices. Ferromagnetic resonance has been measured at millikelvin temperatures on PFIB-processed YIG samples using planar microwave circuits. Furthermore, we demonstrate strong coupling between superconducting resonator and YIG ferromagnetic resonance modes by maintaining reasonably low loss while reducing the system down to the micron scale. This achievement of strong coupling on-chip is a crucial step toward fabrication of functional hybrid quantum devices that advantage from spin-wave and superconducting components.Comment: 10 pages, 6 figure

The change in the surface topography of magnesium under high-flux C ion irradiation

The topography of the surface of the magnesium sample after irradiation by the high-intensity pulsed ion beam of a TEMP-4M accelerator was studied. The irradiation causes the formation of a regular comb structure and the creation of craters, their depth reaches 1-1.5 μ

Magneto-hydrodynamic interaction in a vertical slot filled with ferrofluid

Convection flow in a vertical layer of ferrofluid heated from a side and subject to the transverse magnetic field is studied. A stability map is computed and compared with experimental flow visualizations. It is shown that the excitation of magneto-convection leads to the formation of vertically aligned rolls. The interaction of thermo-gravitational and thermo-magnetic motions results in roll and wave patterns of various spatial orientations. A new thermo-magnetic wave instability mechanism is found to exist for sufficiently large values of magnetic Grashof number

Foundational Response-Time Analysis as Explainable Evidence of Timeliness

The paper introduces foundational response-time analysis (RTA) as a means to produce strong and independently checkable evidence of temporal correctness. In a foundational RTA, each response-time bound calculated comes with an auto-generated certificate of correctness - a short and human-inspectable sequence of machine-checked proofs that formally show the claimed bound to hold. In other words, a foundational RTA yields explainable results that can be independently verified (e.g., by a certification authority) in a rigorous manner (with an automated proof checker). Consequently, the analysis tool itself does not need to be verified nor trusted. As a proof of concept, the paper presents POET, the first foundational RTA tool. POET generates certificates based on Prosa, the to-date largest verified framework for schedulability analysis, which is based on Coq. The trusted computing base is hence reduced to the Coq proof checker and its dependencies. POET currently supports two scheduling policies (earliest-deadline-first, fixed-priority), two preemption models (fully preemptive, fully non-preemptive), arbitrary deadlines, periodic and sporadic tasks, and tasks characterized by arbitrary arrival curves. The paper describes the challenges inherent in the development of a foundational RTA tool, discusses key design choices, and reports on its scalability