scholarly journals Investigating Reversibility of Steps in Petri Nets

2022 ◽  
Vol 183 (1-2) ◽  
pp. 67-96
Author(s):  
David de Frutos Escrig ◽  
Maciej Koutny ◽  
Łukasz Mikulski

In reversible computations one is interested in the development of mechanisms allowing to undo the effects of executed actions. The past research has been concerned mainly with reversing single actions. In this paper, we consider the problem of reversing the effect of the execution of groups of actions (steps). Using Petri nets as a system model, we introduce concepts related to this new scenario, generalising notions used in the single action case. We then present properties arising when reverse actions are allowed in place/transition nets (PT-nets). We obtain both positive and negative results, showing that allowing steps makes reversibility more problematic than in the interleaving/sequential case. In particular, we demonstrate that there is a crucial difference between reversing steps which are sets and those which are true multisets. Moreover, in contrast to sequential semantics, splitting reverses does not lead to a general method for reversing bounded PT-nets. We then show that a suitable solution can be obtained by combining split reverses with weighted read arcs.

Author(s):  
Dana Ganor-Stern

Past research has shown that numbers are associated with order in time such that performance in a numerical comparison task is enhanced when number pairs appear in ascending order, when the larger number follows the smaller one. This was found in the past for the integers 1–9 ( Ben-Meir, Ganor-Stern, & Tzelgov, 2013 ; Müller & Schwarz, 2008 ). In the present study we explored whether the advantage for processing numbers in ascending order exists also for fractions and negative numbers. The results demonstrate this advantage for fraction pairs and for integer-fraction pairs. However, the opposite advantage for descending order was found for negative numbers and for positive-negative number pairs. These findings are interpreted in the context of embodied cognition approaches and current theories on the mental representation of fractions and negative numbers.


2020 ◽  
Vol 13 (1) ◽  
pp. 315
Author(s):  
Malte Schäfer ◽  
Manuel Löwer

With the intent of summing up the past research on ecodesign and making it more accessible, we gather findings from 106 existing review articles in this field. Five research questions on terminology, evolution, barriers and success factors, methods and tools, and synergies, guide the clustering of the resulting 608 statements extracted from the reference. The quantitative analysis reveals that the number of review articles has been increasing over time. Furthermore, most statements originate from Europe, are published in journals, and address barriers and success factors. For the qualitative analysis, the findings are grouped according to the research question they address. We find that several names for similar concepts exist, with ecodesign being the most popular one. It has evolved from “end-of-pipe” pollution prevention to a more systemic concept, and addresses the complete life cycle. Barriers and success factors extend beyond the product development team to management, customers, policymakers, and educators. The number of ecodesign methods and tools available to address them is large, and more reviewing, testing, validation, and categorization of the existing ones is necessary. Synergies between ecodesign and other research disciplines exist in theory, but require implementation and testing in practice.


Author(s):  
Yu Yao ◽  
Heng Liang ◽  
Xin Fang ◽  
Shengnan Zhang ◽  
Zikang Xing ◽  
...  

AbstractIndoleamine 2,3-dioxygenase 1 (IDO1), a monomeric heme-containing enzyme, catalyzes the first and rate-limiting step in the kynurenine pathway of tryptophan metabolism, which plays an important role in immunity and neuronal function. Its implication in different pathophysiologic processes including cancer and neurodegenerative diseases has inspired the development of IDO1 inhibitors in the past decades. However, the negative results of the phase III clinical trial of the would-be first-in-class IDO1 inhibitor (epacadostat) in combination with an anti-PD1 antibody (pembrolizumab) in patients with advanced malignant melanoma call for a better understanding of the role of IDO1 inhibition. In this review, the current status of the clinical development of IDO1 inhibitors will be introduced and the key pre-clinical and clinical data of epacadostat will be summarized. Moreover, based on the cautionary notes obtained from the clinical readout of epacadostat, strategies for the identification of reliable predictive biomarkers and pharmacodynamic markers as well as for the selection of the tumor types to be treated with IDO1inhibitors will be discussed.


Water Policy ◽  
2020 ◽  
Vol 22 (5) ◽  
pp. 768-788
Author(s):  
Nitin Bassi ◽  
Guido Schmidt ◽  
Lucia De Stefano

Abstract The main objective of this research paper is to assess the extent to which the concept of water accounting has been applied for water management at the river basin scale in India. For this, the study first assesses the importance given to the use of water accounting for water management in India's national water policy. It then analyses the evolution of water accounting approaches in India through a systematic review of the past research studies on the theme. Further, it looks at their contribution to decision-making concerning allocation of water resources and resolving conflicts over water sharing. Finally, it identifies the existing gaps in the methodologies for water accounting so far used in India.


2016 ◽  
Vol 49 (3) ◽  
pp. 243-254 ◽  
Author(s):  
Timofey Agarin ◽  
Miķelis Grīviņš

The paper investigates the dynamics and volution of issues on the agenda of Baltic environmental non-governmental organisations (NGOs) since the collapse of communism. The past research on Baltic environment activism suggests that these enjoy high visibility because they tapped the core societal views of natural environment as a crucial asset of a nation. As we demonstrate in this paper, the changes in agendas of Baltic environmental non-governmental organisations (ENGOs) make clear that the rhetorical toolbox of ‘national environment’ is often used to mainly achieve greater financial gains for individual members, rather than for society at large. We illustrate how the dearth of economic opportunities for domestic public has impacted perceptions of ‘nature’ advocated by the environmental activists, focussing specifically on national perceptions of ownership and the resulting actions appropriating ‘nature’ as a source for economic development, only tangentially attaining environmental outcomes on the way. The vision that the ‘environment’ is an economic resource allowed ENGO activists to cooperate with the domestic policymaking, while tapping international networks and donors for funding. Throughout the past decades they worked to secure their own and their members’ particularistic economic interests and, as we demonstrate, remained disengaged from the political process and failed to develop broader reproach with publics.


Science ◽  
2021 ◽  
Vol 371 (6533) ◽  
pp. 1014-1019
Author(s):  
Michael E. Mann ◽  
Byron A. Steinman ◽  
Daniel J. Brouillette ◽  
Sonya K. Miller

Past research argues for an internal multidecadal (40- to 60-year) oscillation distinct from climate noise. Recent studies have claimed that this so-termed Atlantic Multidecadal Oscillation is instead a manifestation of competing time-varying effects of anthropogenic greenhouse gases and sulfate aerosols. That conclusion is bolstered by the absence of robust multidecadal climate oscillations in control simulations of current-generation models. Paleoclimate data, however, do demonstrate multidecadal oscillatory behavior during the preindustrial era. By comparing control and forced “Last Millennium” simulations, we show that these apparent multidecadal oscillations are an artifact of pulses of volcanic activity during the preindustrial era that project markedly onto the multidecadal (50- to 70-year) frequency band. We conclude that there is no compelling evidence for internal multidecadal oscillations in the climate system.


Author(s):  
Ishowriya Yumnam

In this review article the usage of waste sewage sludge and the biomass ash for improving the engineering and non-engineering properties’ of both concrete and soil are discussed in detail. Numerous past research works were studied in detail so as to predict the behavior of biomass ash and waste sewage sludge when used for the stabilization process of soil and concrete. Past studies related to the usage of stabilized sewage sludge and biomass ash were studied in a detailed manner and depending upon the past studies several conclusions has been drawn which are discussed further. Several studies related to the usage of the waste sewage sludge for improving soil physical, chemical and biological properties showed that the usage of waste sewage sludge improve the physical properties, chemical properties, macro-nutriential properties and micro-nutriential properties up to a great extent. Depending upon the results of the past studies it can be concluded that the usage of sewage sludge has positive impact over all the properties of soil and this waste should be utilized in improving the properties of soil rather than dumping. Numerous studies related to the usage of the biomass ash showed that biomass ash has positive impact over both soil as well as concrete. Studies related to the usage of the biomass ash in soil showed that there was a positive response of the stabilized soil after its stabilization with the biomass ash. Studies related to the usage of the biomass ash in concrete showed that the biomass ash can be used up to 10 percent replacement of the ordinary Portland cement so as to attain maximum strength results from it.


1988 ◽  
Vol 52 (2) ◽  
pp. 75-85 ◽  
Author(s):  
Mary C. Gilly

In the past, research has found that the portrayal of sex roles in advertising has not reflected equality or reality. Further, studies typically have examined only U.S. advertising, leaving open the question of cultural influence on advertising's sex role portrayals. The author offers a new analysis of sex roles in advertising and compares content analysis findings for U.S., Australian, and Mexican television advertisements. Results reveal differences in the portrayal of the sexes in U.S. advertisements. Australian advertisements show somewhat fewer sex role differences and Mexican advertisements show slightly more sex role differences than U.S. advertisements. Stereotypes are found in the advertising of all three countries, but are manifested in different ways.


2003 ◽  
Vol 8 (1) ◽  
pp. 45-58 ◽  
Author(s):  
Cherylynn Bassani

This paper discusses changes in Japanese parenting over the past two generations. Using an inductive approach to the understanding of Japanese families, 10 separate families were theoretically sampled in the Kansai area during the summer of 2000. Concepts surrounding changing parenting emerged from talks with parents. Four interrelated concepts are eminent in the interviews: the rise of individual ethics in parenting, changing parental roles, impacts of changes on children, and romanticized parenting. Key generational and gender differences are apparent across all four concepts. Concepts that emerged from these interviews reflect changes in society and the family that past research has addressed.


i-com ◽  
2015 ◽  
Vol 14 (3) ◽  
Author(s):  
Raquel Oliveira ◽  
Sophie Dupuy-Chessa ◽  
Gaëlle Calvary

AbstractInteractive systems have largely evolved over the past years. Nowadays, different users can interact with systems on different devices and in different environments. The user interfaces (UIs) are expected to cope with such variety. Plastic UIs have the capacity to adapt to changes in their context of use while preserving usability. Such capability enhances UIs, however, it adds complexity on them. We propose an approach to verifying interactive systems considering this adaptation capability of the UIs. The approach applies two formal techniques: model checking, to the verification of properties over the system model, and equivalence checking, to compare different versions of a UI, thereby identifying different levels of UI equivalence. We apply the approach to a case study in the nuclear power plant domain in which several UI are analyzed, properties are verified, and the level of equivalence between them is demonstrated.


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