Decision Procedures for Several Properties of Reactive System Specifications

Author(s):  
Noriaki Yoshiura
2012 ◽  
Vol 43 (2) ◽  
pp. 109-122 ◽  
Author(s):  
O. V. Sharypov ◽  
I. S. Anufriev

2019 ◽  
Author(s):  
Rebecca Lindsey ◽  
Nir Goldman ◽  
Laurence E. Fried ◽  
Sorin Bastea

<p>The interatomic Chebyshev Interaction Model for Efficient Simulation (ChIMES) is based on linear combinations of Chebyshev polynomials describing explicit two- and three-body interactions. Recently, the ChIMES model has been developed and applied to a molten metallic system of a single atom type (carbon), as well as a non-reactive molecular system of two atom types at ambient conditions (water). Here, we continue application of ChIMES to increasingly complex problems through extension to a reactive system. Specifically, we develop a ChIMES model for carbon monoxide under extreme conditions, with built-in transferability to nearby state points. We demonstrate that the resulting model recovers much of the accuracy of DFT while exhibiting a 10<sup>4</sup>increase in efficiency, linear system size scalability and the ability to overcome the significant system size effects exhibited by DFT.</p>


2019 ◽  
Author(s):  
Jonas Landsgesell ◽  
Oleg Rud ◽  
Pascal Hebbeker ◽  
Raju Lunkad ◽  
Peter Košovan ◽  
...  

We introduce the grand-reaction method for coarse-grained simulations of acid-base equilibria in a system coupled to a reservoir at a given pH and concentration of added salt. It can be viewed as an extension of the constant-pH method and the reaction ensemble, combining explicit simulations of reactions within the system, and grand-canonical exchange of particles with the reservoir. Unlike the previously introduced methods, the grand-reaction method is applicable to acid-base equilibria in the whole pH range because it avoids known artifacts. However, the method is more general, and can be used for simulations of any reactive system coupled to a reservoir of a known composition. To demonstrate the advantages of the grand-reaction method, we simulated a model system: A solution of weak polyelectrolytes in equilibrium with a buffer solution. By carefully accounting for the exchange of all constituents, the method ensures that all chemical potentials are equal in the system and in the multi-component reservoir. Thus, the grand-reaction method is able to predict non-monotonic swelling of weak polyelectrolytes as a function of pH, that has been known from mean-field predictions and from experiments but has never been observed in coarse-grained simulations. Finally, we outline possible extensions and further generalizations of the method, and provide a set of guidelines to enable safe usage of the method by a broad community of users.<br><br>


2013 ◽  
Vol 833 ◽  
pp. 125-129
Author(s):  
Hao Zhang ◽  
Zhong Min Zhao ◽  
Long Zhang ◽  
Shuan Jie Wang

By introducing (CrO3+Al) high-energy thermit into (Ti+B4C) system and designing adiabatic temperature of reactive system as 3000°C,3200°C, 3400°C, 3600°C and 3800°C respectively, a series of solidified TiC-TiB2were prepared by combustion synthesis in ultrahigh gravity field with the acceleration 2000 g. XRD, FESEM and EDS results showed that the solidified TiCTiB2were composed of a number of TiB2primary platelets, irregular TiC secondary grains, and a few of isolated Al2O3inclusions and Cr-based alloy. Because of the enhanced Stokes flow in mixed melt with the increased adiabatic temperature, Al2O3droplets were promoted to float up and separate from TiC-TiB2-Me liquid while constitutional distribution became more and more uniform in TiC-TiB2-Me liquid, resulting in not only the sharply-reduced Al2O3inclusions in the solidified ceramic but also the refined microstructure and the improved homogeneity in the ceramic, and ultrafine-grained microstructure with a average thickness of TiB2platelets smaller than 1μm began to appear in near-full-density ceramic as the adiabatic temperature exceeded 3600°C, so the densification, fracture toughness and flexural strength of the ceramic were enhanced with the increased adiabatic temperature of the reactive system.


1991 ◽  
Vol 15 (3-4) ◽  
pp. 255-274
Author(s):  
Rohit Parikh

We study monotonic and non-monotonic Logics of Knowledge, giving decision procedures and completeness results. In particular we develop a model theory for a non-monotonic Logic of Knowledge and show that it corresponds exactly to normal applications of a non-monotonic rule of inference due to McCarthy.


2021 ◽  
Vol 184 ◽  
pp. 469-475
Author(s):  
Mohamed Nahri ◽  
Azedine Boulmakoul ◽  
Lamia Karim ◽  
Ahmed Lbath
Keyword(s):  

1993 ◽  
Vol 18 (2-4) ◽  
pp. 163-182
Author(s):  
Alexander Leitsch

It is investigated, how semantic clash resolution can be used to decide some classes of clause sets. Because semantic clash resolution is complete, the termination of the resolution procedure on a class Γ gives a decision procedure for Γ. Besides generalizing earlier results we investigate the relation between termination and clause complexity. For this purpose we define the general concept of atom complexity measure and show some general results about termination in terms of such measures. Moreover, rather than using fixed resolution refinements we define an algorithmic generator for decision procedures, which constructs appropriate semantic refinements out of the syntactical structure of the clause sets. This method is applied to the Bernays – Schönfinkel class, where it gives an efficient (resolution) decision procedure.


Author(s):  
Robert C. Schmidt

AbstractIn this short paper, I look back at the early stages of the Corona crisis, around early February 2020, and compare the situation with the climate crisis. Although these two problems unfold on a completely different timescale (weeks in the case of Corona, decades in the case of climate change), I find some rather striking similarities between these two problems, related with issues such as uncertainty, free-rider incentives, and disincentives of politicians to adequately address the respective issue with early, farsighted and possibly harsh policy measures. I then argue that for complex problems with certain characteristics, it may be necessary to establish novel political decision procedures that sidestep the normal, day-to-day political proceedings. These would be procedures that actively involve experts, and lower the involvement of political parties as far as possible to minimize the decision-makers’ disincentives.


2007 ◽  
Vol 258 (2) ◽  
pp. 115-124 ◽  
Author(s):  
Bastian Schmid ◽  
Michael Döker ◽  
Jürgen Gmehling

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