scholarly journals Minimal Coverability Tree Construction Made Complete and Efficient

2020 ◽  
pp. 237-256 ◽  
Author(s):  
Alain Finkel ◽  
Serge Haddad ◽  
Igor Khmelnitsky
Keyword(s):  
Petri Net ◽  
Execution Time ◽  
The Other ◽  
Maximal Elements ◽  
Simple Modification ◽  
Tree Algorithm ◽  
Tree Construction ◽  
The One ◽  
Additional Space ◽  
Additional Memory

AbstractDownward closures of Petri net reachability sets can be finitely represented by their set of maximal elements called the minimal coverability set or Clover. Many properties (coverability, boundedness, ...) can be decided using Clover, in a time proportional to the size of Clover. So it is crucial to design algorithms that compute it efficiently. We present a simple modification of the original but incomplete Minimal Coverability Tree algorithm (MCT), computing Clover, which makes it complete: it memorizes accelerations and fires them as ordinary transitions. Contrary to the other alternative algorithms for which no bound on the size of the required additional memory is known, we establish that the additional space of our algorithm is at most doubly exponential. Furthermore we have implemented a prototype which is already very competitive: on benchmarks it uses less space than all the other tools and its execution time is close to the one of the fastest tool.

THE APPLICATION OF PETRI NETS TO WORKFLOW MANAGEMENT

1998 ◽  
Vol 08 (01) ◽  
pp. 21-66 ◽  
Author(s):  
W. M. P. VAN DER AALST
Keyword(s):  
Petri Nets ◽  
Petri Net ◽  
Business Processes ◽  
State Of The Art ◽  
Workflow Management ◽  
Explicit Representation ◽  
The Other ◽  
Application Domain ◽  
Analysis Techniques ◽  
The One

Workflow management promises a new solution to an age-old problem: controlling, monitoring, optimizing and supporting business processes. What is new about workflow management is the explicit representation of the business process logic which allows for computerized support. This paper discusses the use of Petri nets in the context of workflow management. Petri nets are an established tool for modeling and analyzing processes. On the one hand, Petri nets can be used as a design language for the specification of complex workflows. On the other hand, Petri net theory provides for powerful analysis techniques which can be used to verify the correctness of workflow procedures. This paper introduces workflow management as an application domain for Petri nets, presents state-of-the-art results with respect to the verification of workflows, and highlights some Petri-net-based workflow tools.

Concurrency Control Protocol for Real-Time Database and the Analysis Base on Petri Net

2010 ◽  
Vol 143-144 ◽  
pp. 12-17
Author(s):  
Jun Chen ◽  
Yu Fen Wang ◽  
Jian Ping Wang
Keyword(s):  
Real Time ◽  
Petri Net ◽  
Concurrency Control ◽  
The Other ◽  
Time Limits ◽  
Control Protocol ◽  
Other Hand ◽  
Congestion Problems ◽  
Real Time Database ◽  
The One

In the article a new concurrency control protocol for real-time database (RTCC) is proposed. The protocol based on the traditional speculative concurrency control protocol (SCC). It dynamically establish the maximum of shadow to reasonably use the resources of system and add the quasi-commit phase to avoid many unnecessary restarting and enhance the concurrency of transaction. The theory of Petri net proof and results of experiment show that this protocol is feasible and effective , and it can meet the needs of real-time transaction. Speculative Concurrency Control is suitable especially for real-time database[1]. On the one hand, SCC is similar to PCC, to detect potentially harmful conflict as early as possible, so as to start a replacement schedule, thereby increasing the opportunities for transactions to meet time limits. On the other hand, SCC is similar to OCC, it allows the concurrency of conflict transaction and, therefore, avoids unnecessary matters that may affect the timely submission of delay. As a result, it alleviates the congestion problems and PCC restart OCC's problems, in order to better meet the transaction deadline. Based on the fact above mentioned, we propose a suitable real-time database concurrency control protocol [2,3] (RTCC: Concurrency Control protocol for Real-Time). The protocol of the SCC protocol on the traditional basis with a series of improvements can avoid a large number of unnecessary transaction restart and improve concurrency. Finally, by Petri net theory it can be proved feasible and correct.

scholarly journals Coloured Petri Nets Extended with Place Capacities, Test Arcs and Inhibitor Arcs

1992 ◽  
Vol 21 (398) ◽  
Author(s):  
Søren Christensen ◽  
Niels Damgaard Hansen
Keyword(s):  
Petri Nets ◽  
Petri Net ◽  
The Other ◽  
Coloured Petri Nets ◽  
Basic Properties ◽  
New Concepts ◽  
Special Cases ◽  
The One ◽  
Net Framework ◽  
Informal Description

In this paper we show how to extend Coloured Petri Nets (CP-nets), with three new modelling primitives - place capacities, test arcs and inhibitor arcs. The new modelling primitives are introduced to improve the possibilities of creating models that are on the one hand compact and comprehensive and on the other hand easy to develop, understand and analyse. A number of different place capacity and inhibitor concepts have been suggested earlier, e.g. integer and multi-set capacities and zero-testing and threshold inhibitors. These concepts can all be described as special cases of the more general place capacity and inhibitor concepts defined in this paper. We give an informal description of the new concepts and show how the concepts can be fonnally defined and integrated in the Petri net framework keeping the basic properties of CP-nets. In contrast to a number of the previously suggested extensions to CP-nets the new modelling primitives preserve the concurrency properties of CP-nets. We show how CP-nets with place capacities, test arcs and inhibitor arcs can be transformed into behaviourally equivalent CP-nets without these primitives. From this we conclude that the basic properties of CP-nets are preserved and that the theory developed for CP-nets can be applied to the extended CP-nets. Finally, we discuss how to generalise the analysis methods of CP-nets to cover the place capacities, test arcs and inhibitor arcs.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

Stories and the Self

2020 ◽  
Vol 32 (2) ◽  
pp. 47-58 ◽  
Author(s):  
Stefan Krause ◽  
Markus Appel
Keyword(s):  
Meta Analysis ◽  
The Self ◽  
The Other ◽  
Lower Degree ◽  
Contrast Effects ◽  
Self Perception ◽  
Self Perceptions ◽  
Other Hand ◽  
The One ◽  
Implicit And Explicit

Abstract. Two experiments examined the influence of stories on recipients’ self-perceptions. Extending prior theory and research, our focus was on assimilation effects (i.e., changes in self-perception in line with a protagonist’s traits) as well as on contrast effects (i.e., changes in self-perception in contrast to a protagonist’s traits). In Experiment 1 ( N = 113), implicit and explicit conscientiousness were assessed after participants read a story about either a diligent or a negligent student. Moderation analyses showed that highly transported participants and participants with lower counterarguing scores assimilate the depicted traits of a story protagonist, as indicated by explicit, self-reported conscientiousness ratings. Participants, who were more critical toward a story (i.e., higher counterarguing) and with a lower degree of transportation, showed contrast effects. In Experiment 2 ( N = 103), we manipulated transportation and counterarguing, but we could not identify an effect on participants’ self-ascribed level of conscientiousness. A mini meta-analysis across both experiments revealed significant positive overall associations between transportation and counterarguing on the one hand and story-consistent self-reported conscientiousness on the other hand.

Radioimmunotherapy for treatment of acute myeloid leukaemia and myelodysplastic syndrome

2005 ◽  
Vol 44 (03) ◽  
pp. 107-117
Author(s):  
R. G. Meyer ◽  
W. Herr ◽  
A. Helisch ◽  
P. Bartenstein ◽  
I. Buchmann
Keyword(s):  
Acute Myeloid Leukaemia ◽  
Myeloid Leukaemia ◽  
Primary Tumour ◽  
The Other ◽  
Haematopoietic Stem Cell ◽  
Other Hand ◽  
Primary Reduction ◽  
The One ◽  
Acute Myeloid

SummaryThe prognosis of patients with acute myeloid leukaemia (AML) has improved considerably by introduction of aggressive consolidation chemotherapy and haematopoietic stem cell transplantation (SCT). Nevertheless, only 20-30% of patients with AML achieve long-term diseasefree survival after SCT. The most common cause of treatment failure is relapse. Additionally, mortality rates are significantly increased by therapy-related causes such as toxicity of chemotherapy and complications of SCT. Including radioimmunotherapies in the treatment of AML and myelodyplastic syndrome (MDS) allows for the achievement of a pronounced antileukaemic effect for the reduction of relapse rates on the one hand. On the other hand, no increase of acute toxicity and later complications should be induced. These effects are important for the primary reduction of tumour cells as well as for the myeloablative conditioning before SCT.This paper provides a systematic and critical review of the currently used radionuclides and immunoconjugates for the treatment of AML and MDS and summarizes the literature on primary tumour cell reductive radioimmunotherapies on the one hand and conditioning radioimmunotherapies before SCT on the other hand.

Das Ende der Postdemokratie, den Pessimismus überwinden.

2017 ◽  
Vol 47 (188) ◽  
pp. 487-494
Author(s):  
Daniel Mullis
Keyword(s):  
Political Thought ◽  
Social Dynamics ◽  
Social Conditions ◽  
The Other ◽  
Economic Decline ◽  
Far Right ◽  
Windows Of Opportunity ◽  
Political Events ◽  
Political Struggles ◽  
The One

In recent years, political and social conditions have changed dramatically. Many analyses help to capture these dynamics. However, they produce political pessimism: on the one hand there is the image of regression and on the other, a direct link is made between socio-economic decline and the rise of the far-right. To counter these aspects, this article argues that current political events are to be understood less as ‘regression’ but rather as a moment of movement and the return of deep political struggles. Referring to Jacques Ranciere’s political thought, the current conditions can be captured as the ‘end of post-democracy’. This approach changes the perspective on current social dynamics in a productive way. It allows for an emphasis on movement and the recognition of the windows of opportunity for emancipatory struggles.

Tolerance is theoretical and practical principles

1996 ◽  
pp. 13-23
Author(s):  
Mykhailo Babiy
Keyword(s):  
Religious Diversity ◽  
The Other ◽  
Nodal Points ◽  
Characteristic Features ◽  
The One ◽  
Ukrainian Society

Political ideological pluralism, religious diversity are characteristic features of modern Ukrainian society. On the one hand, multiculturalism, socio-political, religious differentiation of the latter appear as important characteristics of its democracy, as a practical expression of freedom, on the other - as a factor that led to the deconsocialization of society, gave rise to "nodal points" of tension, confrontational processes, in particular, in political and religious spheres.

The Salvage of Ideas: Schumpeter and the Core Problems Still Confronting Economics

2003 ◽  
pp. 15-26
Author(s):  
P. Wynarczyk
Keyword(s):  
The Other ◽  
The Core ◽  
Other Hand ◽  
The One

Two aspects of Schumpeter' legacy are analyzed in the article. On the one hand, he can be viewed as the custodian of the neoclassical harvest supplementing to its stock of inherited knowledge. On the other hand, the innovative character of his works is emphasized that allows to consider him a proponent of hetherodoxy. It is stressed that Schumpeter's revolutionary challenge can lead to radical changes in modern economics.

Hidden “holes” in the capital of banks and the supply of credit to the real sector of economy

2018 ◽  
pp. 49-68 ◽  
Author(s):  
M. E. Mamonov
Keyword(s):  
Credit Risk ◽  
The Other ◽  
Real Sector ◽  
Capital Management ◽  
Loan Loss ◽  
Short Term ◽  
The Real ◽  
Ex Post ◽  
The One

Our analysis documents that the existence of hidden “holes” in the capital of not yet failed banks - while creating intertemporal pressure on the actual level of capital - leads to changing of maturity of loans supplied rather than to contracting of their volume. Long-term loans decrease, whereas short-term loans rise - and, what is most remarkably, by approximately the same amounts. Standardly, the higher the maturity of loans the higher the credit risk and, thus, the more loan loss reserves (LLP) banks are forced to create, increasing the pressure on capital. Banks that already hide “holes” in the capital, but have not yet faced with license withdrawal, must possess strong incentives to shorten the maturity of supplied loans. On the one hand, it raises the turnovers of LLP and facilitates the flexibility of capital management; on the other hand, it allows increasing the speed of shifting of attracted deposits to loans to related parties in domestic or foreign jurisdictions. This enlarges the potential size of ex post revealed “hole” in the capital and, therefore, allows us to assume that not every loan might be viewed as a good for the economy: excessive short-term and insufficient long-term loans can produce the source for future losses.

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