Trace Inclusion for One-Counter Nets Revisited

One-Counter nets (OCN) consist of a nondeterministic finite control and a single integer counter that cannot be fully tested for zero. They form a natural subclass of both One-Counter Automata, which allow zero-tests and Petri Nets/VASS, which allow multiple such weak counters. The trace inclusion problem has recently been shown to be undecidable for OCN. In this paper, we contrast the complexity of two natural restrictions which imply decidability. First, we show that trace inclusion between an OCN and a deterministic OCN is NL-complete, even with arbitrary binary-encoded initial counter-values as part of the input. Secondly, we show Ackermannian completeness of for the trace universality problem of nondeterministic OCN. This problem is equivalent to checking trace inclusion between a finite and a OCN-process

Utilization of casting ladle lining enthalpy for heating gas savings in the course of ladle preheating

During the long-term staying of steel in ladle within the period from the tap until the end of continuous casting takes place a great amount of heat accumulates in lining. For its utilization is necessary to optimize heat operation of ladle lining. The demanded enthalpy of ladle before tap and the real enthalpy of ladle as things stand are needed for heating gas savings during the preheating. The enthalpy changes of ladle lining are in the course of their cycling in steelworks solved by the model of lining thermal state. For that purpose were conducted the operation measurements to find out the ladle lining thermal field within the whole technological flow

The Parametric Ordinal-Recursive Complexity of Post Embedding Problems

Post Embedding Problems are a family of decision problems based on the interaction of a rational relation with the subword embedding ordering, and are used in the literature to prove non multiply-recursive complexity lower bounds. We refine the construction of Chambart and Schnoebelen (LICS 2008) and prove parametric lower bounds depending on the size of the alphabet.Comment: 16 + vii page

Integer Vector Addition Systems with States

This paper studies reachability, coverability and inclusion problems for Integer Vector Addition Systems with States (ZVASS) and extensions and restrictions thereof. A ZVASS comprises a finite-state controller with a finite number of counters ranging over the integers. Although it is folklore that reachability in ZVASS is NP-complete, it turns out that despite their naturalness, from a complexity point of view this class has received little attention in the literature. We fill this gap by providing an in-depth analysis of the computational complexity of the aforementioned decision problems. Most interestingly, it turns out that while the addition of reset operations to ordinary VASS leads to undecidability and Ackermann-hardness of reachability and coverability, respectively, they can be added to ZVASS while retaining NP-completness of both coverability and reachability.Comment: 17 pages, 2 figure

Supplementary data for the article: Ognjanović, M.; Stanković, D.; Ming, Y.; Zhang, H.; Jančar, B.; Dojčinović, B. P.; Prijović, Ž.; Antić, B. Bifunctional (Zn,Fe)3O4 Nanoparticles: Tuning Their Efficiency for Potential Application in Reagentless Glucose Biosensors and Magnetic Hyperthermia. Journal of Alloys and Compounds 2019, 777, 454–462. https://doi.org/10.1016/j.jallcom.2018.10.369

Supplementary material for: [https://www.sciencedirect.com/science/article/pii/S0925838818340684?via%3Dihub]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/361]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/2797

On the complexity of resource-bounded logics

We revisit decidability results for resource-bounded logics and use decision problems for vector addition systems with states (VASS) to characterise the complexity of (decidable) model-checking problems. We show that the model-checking problem for the logic RB+-ATL is 2EXPTIME-complete by using recent results on alternating VASS. In addition, we establish that the model-checking problem for RBTL is decidable and has the same complexity as for RBTL* (the extension of RBTL with arbitrary path formulae), namely EXPSPACE-complete, proving a new decidability result as a by-product of the approach. Finally, we establish that the model-checking problem for RB+-ATL* is decidable by a reduction to parity games, and show how to synthesise values for resource parameters

Weak Bisimulation Approximants

Bisimilarity ∼ and weak bisimilarity ≈ are canonical notions of equivalence between processes, which are defined co-inductively, but may be approached – and even reached – by their (transfinite) inductively-defined approximants ∼α and ≈α. For arbitrary processes this approximation may need to climb arbitrarily high through the infinite ordinals before stabilising. In this paper we consider a simple yet well-studied process algebra, the Basic Parallel Processes (BPP), and investigate for this class of processes the minimal ordinal α such that ≈ = ≈α. The main tool in our investigation is a novel proof of Dickson’s Lemma. Unlike classical proofs, the proof we provide gives rise to a tight ordinal bound, of ω n, on the order type of non-increasing sequences of n-tuples of natural numbers. With this we are able to reduce a long-standing bound on the approximation hierarchy for weak bisimilarity ≈ over BPP, and show that ≈ = ≈ω ω

Supplementary data for the article: Ognjanović, M.; Stanković, D.; Ming, Y.; Zhang, H.; Jančar, B.; Dojčinović, B. P.; Prijović, Ž.; Antić, B. Bifunctional (Zn,Fe)3O4 Nanoparticles: Tuning Their Efficiency for Potential Application in Reagentless Glucose Biosensors and Magnetic Hyperthermia. Journal of Alloys and Compounds 2019, 777, 454–462. https://doi.org/10.1016/j.jallcom.2018.10.369

Supplementary material for: [https://www.sciencedirect.com/science/article/pii/S0925838818340684?via%3Dihub]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/361]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/2797

Minimal Cost Reachability/Coverability in Priced Timed Petri Nets

Abstract. We extend discrete-timed Petri nets with a cost model that assigns token storage costs to places and firing costs to transitions, and study the minimal cost reachability/coverability problem. We show that the minimal costs are computable if all storage/transition costs are non-negative, while even the question of zero-cost coverability is undecidable in the case of general integer costs.