Investigating Reversibility of Steps in Petri Nets

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.

College Admission with Multidimensional Privileges: The Brazilian Affirmative Action Case

In 2012, Brazilian public universities were mandated to use affirmative action policies for candidates from racial and income minorities. We show that the policy makes the students’ affirmative action status a strategic choice and may reject high-achieving minority students while admitting low-achieving majority students. Empirical data shows evidence consistent with this type of unfairness in more than 49 percent of the programs. We propose a selection criterion and an incentive-compatible mechanism that, for a wider range of similar problems and the one in Brazil in particular, is fair and removes any gain from strategizing over the privileges claimed. (JEL I23, O15, I28, J15, D82, H52)

Extensions of several coprime results to good action case

Let [Formula: see text] and [Formula: see text] be groups where [Formula: see text] acts on [Formula: see text] by automorphisms. We say “the action of[Formula: see text] on[Formula: see text] is good” if the equality [Formula: see text] holds for any subgroup [Formula: see text] of [Formula: see text] and for any [Formula: see text]-invariant subgroup [Formula: see text] of [Formula: see text]. It is straightforward that every coprime action is a good action. In this work, we extend some results due to Ward, Gross, Shumyatsky, Jabara and Meng and Guo under coprime action to good action.

Remote Virtual Simulation for Incident Commanders—Cognitive Aspects

Due to the COVID-19 restrictions, on-site Incident Commander (IC) practical training and examinations in Sweden were canceled as of March 2020. The graduation of one IC class was, however, conducted through Remote Virtual Simulation (RVS), the first such examination to our current knowledge. This paper presents the necessary enablers for setting up RVS and its influence on cognitive aspects of assessing practical competences. Data were gathered through observations, questionnaires, and interviews from students and instructors, using action-case research methodology. The results show the potential of RVS for supporting higher cognitive processes, such as recognition, comprehension, problem solving, decision making, and allowed students to demonstrate whether they had achieved the required learning objectives. Other reported benefits were the value of not gathering people (imposed by the pandemic), experiencing new, challenging incident scenarios, increased motivation for applying RVS based training both for students and instructors, and reduced traveling (corresponding to 15,400 km for a class). While further research is needed for defining how to integrate RVS in practical training and assessment for IC education and for increased generalizability, this research pinpoints current benefits and limitations, in relation to the cognitive aspects and in comparison, to previous examination formats.

Batak Christian Protestant Church's View Concerning Ecology

This paper examines a discussion about ecology focus on Batak Christian Protestant Church's view and action. The study's reason is based on what the church said about ecological problems in their faith declaration. Furthermore, looking Batak Christian Protestant Church (HKBP) litigates connected to ecological action case in Indonesia. Methodology in this research is literary, looking at the book, internet, and faith confession of the HKBP. Gathering the data and then analyze is the approach used to discuss the issue. This study traced that the HKBP has mentioned ecology in their faith confession. In their view, HKBP argues that God created man in his residence and place of work in this world (Gen. 2:5-15). Therefore, they oppose any environmentally damaging activities, such as burning and cutting down trees in the forest or wilderness (Deuteronomy 5: 20; 19-20). This creed is based on the Word of God as recorded in the scriptures. They also have been activated to protect nature, for example: develop livestock waste into alternative energy (biogas); planting trees in Peak Dolok, Balige North Sumatera; statings local wisdom. Christianity realizes that ecology issues are also part of their problems. What has been done by the HKBP be a positive thing. This action is a good activity for Christianity in Indonesia. Even though we cannot deny the ecology problem is our common problem.

CONSTRUCTIVE COMMUNICATIONS IN THE MANAGEMENT OF INTERPERSONAL CONFLICTS IN THE MEDIATION PROCEDURE

The purpose of the article is to consider the structure of mediation session and standardization of the mediation procedure in the management of interpersonal conflicts. The research methodology is based on the theory of conflict, which understands sociology, the narrative approach, as well as the fundamental scientific developments of sociology and psychology of conflict. In various approaches to the mediation procedure, caucus is regarded as a key stage, since it is it that has the greatest influence on the result of the entire negotiation procedure with the participation of a mediator. The authors describe several cases from the practice of mediation, focusing on the logic of the mediator's action. Case analysis demonstrates the complexity and multivariance of the behavior of the parties to the conflict. As a result of the systematization of practical experience, a number of problematic issues are formulated that require reflection by the mediator in order to predict and influence the situation of the conflict between the parties as efficiently as possible. Such a system of questions of the mediator to oneself allows providing a qualitative study of the conflict situation and building a constructive line of interaction between the parties to the conflict participating in the mediation procedure. As a result of forecasting problem situations, the use of answers to these questions will bring closer the possibility of negotiating a strategy of cooperation. A number of recommendations are offered to novice mediators for better work on the study of the conflict, planning its stages, forecasting and finding mutually acceptable solutions during the caucus stage.