scholarly journals cpalockator: Thread-Modular Analysis with Projections

Author(s):  
Pavel Andrianov ◽  
Vadim Mutilin ◽  
Alexey Khoroshilov

AbstractOur submission to SV-COMP’21 is based on the software verification framework "Image missing" and implements the extension to the thread-modular approach. It considers every thread separately, but in a special environment which models thread interactions. The environment is expressed by projections of normal transitions in each thread. A projection contains a description of possible effects over shared data and synchronization primitives, as well as conditions of its application. Adjusting the precision of the projections, one can find a balance between the speed and the precision of the whole analysis.Implementation on the top of the "Image missing" framework allows combining our approach with existing algorithms and analyses. Evaluation on the sv-benchmarks confirms the scalability and soundness of the approach.

2013 ◽  
Vol 731 ◽  
pp. 223-258
Author(s):  
Francis Fendell ◽  
Paritosh Mokhasi

AbstractIn the early 1970s, George Carrier and coworkers undertook a modular approach to modelling the internal thermofluid-dynamics of tropical cyclones of tropical-depression-or-greater intensity. A novel, relatively simplistic, approximate analysis of the vortex, idealized as axisymmetric, was carried out in the asymptotic limit of large Reynolds number, so that inviscid and diffusive subdomains of the structure were distinguished. Little subsequent work has followed this line of investigation. The indifference has proven problematic because accurate prediction of tropical-cycling intensity remains a challenge for operational forecasting, despite decades of effort at direct integration of comprehensive boundary/initial-value formulations. A contributing factor is that, to achieve solution in real time, such computational treatment of the entire vortex invariably resorts to coarse gridding, and key features remain inadequately resolved. Accordingly, here the modular approach is revisited, with the assistance of: recent observational insights; greatly enhanced computer-processing power; and convenient computational software, which facilitates implementation of a semi-analytic, semi-numerical methodology. Focus is largely, but not exclusively, on the dynamics and energetics occurring in the nominally kilometre-thick, ocean-surface-contiguous boundary layer, especially on influx to the boundary layer and efflux therefrom. The modular approach not only permits the boundary layer, which develops its own highly significant substructure under the high-speed portion of the inviscid vortex, to be well-resolved, but also allows the layer to be investigated in the context of the other tropical-cyclone-structure subdivisions.


1992 ◽  
Vol 21 (391) ◽  
Author(s):  
Søren Christensen ◽  
Laure Petrucci

The use of different High-level Petri net formalisms has made it possible to create Petri net models of large systems. Even though the use of such models allows the modeller to create compact representations of data and action, the size of models has been increasing. A large model can make it difficult to handle the complexity of the modelling as well as the analysis of the total model. It is well-known that the use of a modular approach to modelling has a lot of advantages. A modular approach allows the modeller to consider different parts of the system independently of one another and also to reuse the same module in different systems. A modular approach to analysis is also attractive. It often dramatically decreases the complexity of the analysis task. In this paper, we present modular CP-nets. They are not intended to be used for practical modelling purposes, but they constitute a formal and general framework for discussing different ways of composing individual CP-nets called modules. Modular CP-nets allow us to study composition without restricting the structure of the individual modules. Modular CP-nets are quite simple and do not include syntactical sugar which is convenient and often necessary when modelling in practice. Instead, they have only a few but very general composition constructs. The main result of the paper is the possibility of composing analysis results of the individual modules, in order to obtain results which are valid for the entire modular CP-net. For this purpose, we introduce place invariants at the level of modular CP-nets and we show how such place invariants can be obtained from those of the individual modules. The reader of this paper is assumed to be familiar with the basic definitions of CP-nets and the concept of place invariants. But it is not necessary to be familiar with hierarchical CP-nets.


Author(s):  
B. B. Zvyagin ◽  
D. Yu. Pushcharovsky

AbstractThe modular approach (MA) is applied to the system composed of Ca


2017 ◽  
Vol 27 (02) ◽  
pp. 1750001 ◽  
Author(s):  
Panagiota Fatourou ◽  
Yiannis Nikolakopoulos ◽  
Marina Papatriantafilou

Shared data object implementations that allow non-blocking concurrent operations are useful for in-memory data-processing, especially when they support consistent bulk operations like iterations. We propose an algorithmic implementation for concurrent iterators on shared double-ended queues (deques), building on and complementing a known lock-free deque implementation by M. Michael. The proposed construction is linearizable and wait-free. Moreover, it is read-only, so it does not execute expensive synchronization primitives and it does not interfere with update operations.


2019 ◽  
Author(s):  
Victor Bloemendal ◽  
Floris P. J. T. Rutjes ◽  
Thomas J. Boltje ◽  
Daan Sondag ◽  
Hidde Elferink ◽  
...  

<p>In this manuscript we describe a modular pathway to synthesize biologically relevant (–)-<i>trans</i>-Δ<sup>8</sup>-THC derivatives, which can be used to modulate the pharmacologically important CB<sub>1</sub> and CB<sub>2</sub> receptors. This pathway involves a one-pot Friedel-Crafts alkylation/cyclization protocol, followed by Suzuki-Miyaura cross-coupling reactions and gives rise to a series of new Δ<sup>8</sup>-THC derivatives. In addition, we demonstrate using extensive NMR evidence that similar halide-substituted Friedel-Crafts alkylation/cyclization products in previous articles were wrongly assigned as the para-isomers, which also has consequence for the assignment of the subsequent cross-coupled products and interpretation of their biological activity. </p> <p>Considering the importance of the availability of THC derivatives in medicinal chemistry research and the fact that previously synthesized compounds were wrongly assigned, we feel this research is describing a straightforward pathway into new cannabinoids.</p>


2018 ◽  
Author(s):  
Yaroslav Boyko ◽  
Christopher Huck ◽  
David Sarlah

<div>The first total synthesis of rhabdastrellic acid A, a highly cytotoxic isomalabaricane triterpenoid, has been accomplished in a linear sequence of 14 steps from commercial geranylacetone. The prominently strained <i>trans-syn-trans</i>-perhydrobenz[<i>e</i>]indene core characteristic of the isomalabaricanes is efficiently accessed in a selective manner for the first time through a rapid, complexity-generating sequence incorporating a reductive radical polyene cyclization, an unprecedented oxidative Rautenstrauch cycloisomerization, and umpolung 𝛼-substitution of a <i>p</i>-toluenesulfonylhydrazone with in situ reductive transposition. A late-stage cross-coupling in concert with a modular approach to polyunsaturated side chains renders this a general strategy for the synthesis of numerous family members of these synthetically challenging and hitherto inaccessible marine triterpenoids.</div>


2015 ◽  
Vol 2 (2) ◽  
pp. 22-30
Author(s):  
Lokanadham Naidu Vadlamudi ◽  
◽  
Srinivasulu Asadi ◽  

2020 ◽  
Vol 17 (6) ◽  
pp. 847-856
Author(s):  
Shengbing Ren ◽  
Xiang Zhang

The problem of synthesizing adequate inductive invariants lies at the heart of automated software verification. The state-of-the-art machine learning algorithms for synthesizing invariants have gradually shown its excellent performance. However, synthesizing disjunctive invariants is a difficult task. In this paper, we propose a method k++ Support Vector Machine (SVM) integrating k-means++ and SVM to synthesize conjunctive and disjunctive invariants. At first, given a program, we start with executing the program to collect program states. Next, k++SVM adopts k-means++ to cluster the positive samples and then applies SVM to distinguish each positive sample cluster from all negative samples to synthesize the candidate invariants. Finally, a set of theories founded on Hoare logic are adopted to check whether the candidate invariants are true invariants. If the candidate invariants fail the check, we should sample more states and repeat our algorithm. The experimental results show that k++SVM is compatible with the algorithms for Intersection Of Half-space (IOH) and more efficient than the tool of Interproc. Furthermore, it is shown that our method can synthesize conjunctive and disjunctive invariants automatically


Sign in / Sign up

Export Citation Format

Share Document