scholarly journals Optimization Models for Efficient (t, r) Broadcast Domination in Graphs

Symmetry ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1028
Author(s):  
Poompol Buathong ◽  
Tipaluck Krityakierne
Keyword(s):  
Biological Networks ◽  
Domination Number ◽  
Real Life ◽  
Point Of View ◽  
Optimization Approach ◽  
Grid Graphs ◽  
Theoretical Approaches ◽  
Graphs And Networks ◽  
Domination In Graphs ◽  
Distance Domination

Known to be NP-complete, domination number problems in graphs and networks arise in many real-life applications, ranging from the design of wireless sensor networks and biological networks to social networks. Initially introduced by Blessing et al., the (t,r) broadcast domination number is a generalization of the distance domination number. While some theoretical approaches have been addressed for small values of t,r in the literature; in this work, we propose an approach from an optimization point of view. First, the (t,r) broadcast domination number is formulated and solved using linear programming. The efficient broadcast, whose wasted signals are minimized, is then found by a genetic algorithm modified for a binary encoding. The developed method is illustrated with several grid graphs: regular, slant, and king’s grid graphs. The obtained computational results show that the method is able to find the exact (t,r) broadcast domination number, and locate an efficient broadcasting configuration for larger values of t,r than what can be provided from a theoretical basis. The proposed optimization approach thus helps overcome the limitations of existing theoretical approaches in graph theory.

Generalized Boolean Networks

2010 ◽  
pp. 429-449 ◽  
Author(s):  
Christian Darabos ◽  
Mario Giacobini ◽  
Marco Tomassini
Keyword(s):  
Biological Networks ◽  
Regulatory Networks ◽  
Dynamical Behavior ◽  
Real Life ◽  
Network Models ◽  
Cell Types ◽  
Boolean Networks ◽  
Genetic Regulatory Networks ◽  
Point Of View ◽  
Scale Free

Random Boolean Networks (RBN) have been introduced by Kauffman more than thirty years ago as a highly simplified model of genetic regulatory networks. This extremely simple and abstract model has been studied in detail and has been shown capable of extremely interesting dynamical behavior. First of all, as some parameters are varied such as the network’s connectivity, or the probability of expressing a gene, the RBN can go through a phase transition, going from an ordered regime to a chaotic one. Kauffman’s suggestion is that cell types correspond to attractors in the RBN phase space, and only those attractors that are short and stable under perturbations will be of biological interest. Thus, according to Kauffman, RBN lying at the edge between the ordered phase and the chaotic phase can be seen as abstract models of genetic regulatory networks. The original view of Kauffman, namely that these models may be useful for understanding real-life cell regulatory networks, is still valid, provided that the model is updated to take into account present knowledge about the topology of real gene regulatory networks, and the timing of events, without loosing its attractive simplicity. According to present data, many biological networks, including genetic regulatory networks, seem, in fact, to be of the scale-free type. From the point of view of the timing of events, standard RBN update their state synchronously. This assumption is open to discussion when dealing with biologically plausible networks. In particular, for genetic regulatory networks, this is certainly not the case: genes seem to be expressed in different parts of the network at different times, according to a strict sequence, which depends on the particular network under study. The expression of a gene depends on several transcription factors, the synthesis of which appear to be neither fully synchronous nor instantaneous. Therefore, we have recently proposed a new, more biologically plausible model. It assumes a scale-free topology of the networks and we define a suitable semi-synchronous dynamics that better captures the presence of an activation sequence of genes linked to the topological properties of the network. By simulating statistical ensembles of networks, we discuss the attractors of the dynamics, showing that they are compatible with theoretical biological network models. Moreover, the model demonstrates interesting scaling abilities as the size of the networks is increased.

An attractiveness index based approach for warranty optimization

2015 ◽  
Vol 32 (4) ◽  
pp. 415-431 ◽  
Author(s):  
Prashant M. Ambad ◽  
Makarand S. Kulkarni
Keyword(s):  
Cost Model ◽  
Real Life ◽  
Point Of View ◽  
Design Stage ◽  
Optimization Approach ◽  
Content Type ◽  
Mean Time Between Failures ◽  
Component Selection ◽  
Decision Variables ◽  
Quantitative Manner

Purpose – The purpose of this paper is to develop an attractiveness index-based warranty cost model considering decision variables as design alternatives, warranty duration and support level. Design/methodology/approach – A warranty optimization approach is illustrated using a real life example of an automobile engine with Mean Time Between Failures and Warranty Attractiveness Index as constraints. Findings – It will help to improve the customer satisfaction by giving a more attractive warranty compared to that being offered by the competitors. Practical implications – Approaches that consider the effect of decision variables on attractiveness of a warranty policy in a quantitative manner have received relatively less attention. The paper attempts to capture the attractiveness of warranty from the manufacturer as well as customer point of view. Originality/value – The proposed approach will help manufacturers to take appropriate decisions related to warranty parameters and component selection at the design stage.

scholarly journals Does Cinema and Movie Characters Influence the Formation of Public Opinion?

2020 ◽  
Vol 6 (3) ◽  
pp. 70-78
Author(s):  
A.O. Glotova ◽  
◽  
Keyword(s):  
Public Opinion ◽  
Daily Life ◽  
Real Life ◽  
Modern Society ◽  
Point Of View ◽  
Cultural Identification ◽  
Theoretical Approaches ◽  
Area Of Influence ◽  
Everyday Reality ◽  
The Relationship

in modern society, the problem of the influence of cinema on the viewer and its value-semantic sphere is of great importance. It is worth noting that this area of influence on a person, despite the relevance due to the popularity of this type of product, is poorly studied from the point of view of sociology. During the work, the cultural identification of society through cinematographic art was analyzed, as well as the relationship between the viewer and the movie character. Theoretical approaches to studying the influence of cinema on a person of both foreign and domestic scientists are considered. The analysis allows concluding that the impressions that the viewer receives while watching the film can reach the level of real life impressions and is transferred to the experience of his daily life. Consequently, the products of cinematographic art not only affect the person, but also constitutional various aspects of his everyday reality.

Risk-Based Robust Bidding Strategies for EVs’ Aggregators in Day-ahead Markets with Uncertainty

2020 ◽  
Author(s):  
Ahmed Abdelmoaty ◽  
Wessam Mesbah ◽  
Mohammad A. M. Abdel-Aal ◽  
Ali T. Alawami
Keyword(s):  
Robust Optimization ◽  
Electricity Market ◽  
Real Life ◽  
Optimization Approach ◽  
Case Scenario ◽  
Worst Case ◽  
Bidding Strategies ◽  
Wind Generators ◽  
Proposed Model ◽  
Optimal Bidding

In the recent electricity market framework, the profit of the generation companies depends on the decision of the operator on the schedule of its units, the energy price, and the optimal bidding strategies. Due to the expanded integration of uncertain renewable generators which is highly intermittent such as wind plants, the coordination with other facilities to mitigate the risks of imbalances is mandatory. Accordingly, coordination of wind generators with the evolutionary Electric Vehicles (EVs) is expected to boost the performance of the grid. In this paper, we propose a robust optimization approach for the coordination between the wind-thermal generators and the EVs in a virtual<br>power plant (VPP) environment. The objective of maximizing the profit of the VPP Operator (VPPO) is studied. The optimal bidding strategy of the VPPO in the day-ahead market under uncertainties of wind power, energy<br>prices, imbalance prices, and demand is obtained for the worst case scenario. A case study is conducted to assess the e?effectiveness of the proposed model in terms of the VPPO's profit. A comparison between the proposed model and the scenario-based optimization was introduced. Our results confirmed that, although the conservative behavior of the worst-case robust optimization model, it helps the decision maker from the fluctuations of the uncertain parameters involved in the production and bidding processes. In addition, robust optimization is a more tractable problem and does not suffer from<br>the high computation burden associated with scenario-based stochastic programming. This makes it more practical for real-life scenarios.<br>

Bleak Weather for Sun-Shine AG: A Case Study of Impairment of Assets

2014 ◽  
Vol 30 (2) ◽  
pp. 113-126 ◽  
Author(s):  
Dominic Detzen ◽  
Tobias Stork genannt Wersborg ◽  
Henning Zülch
Keyword(s):  
Real Life ◽  
Accounting Standards ◽  
Point Of View ◽  
Professional Judgment ◽  
Economic Point ◽  
Instructional Resource

ABSTRACT This case originates from a real-life business situation and illustrates the application of impairment tests in accordance with IFRS and U.S. GAAP. In the first part of the case study, students examine conceptual questions of impairment tests under IFRS and U.S. GAAP with respect to applicable accounting standards, definitions, value concepts, and frequency of application. In addition, the case encourages students to discuss the impairment regime from an economic point of view. The second part of the instructional resource continues to provide instructors with the flexibility of applying U.S. GAAP and/or IFRS when students are asked to test a long-lived asset for impairment and, if necessary, allocate any potential impairment. This latter part demonstrates that impairment tests require professional judgment that students are to exercise in the case.

scholarly journals Modeling and theoretical description of magnetic hybrid materials—bridging from meso- to macro-scales

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Andreas M. Menzel ◽  
Hartmut Löwen
Keyword(s):  
Colloidal Particles ◽  
Colloidal Particle ◽  
Theoretical Description ◽  
Point Of View ◽  
Material Behavior ◽  
Theoretical Point ◽  
Mechanical Stiffness ◽  
Theoretical Approaches ◽  
Theoretical Predictions ◽  
Particle Level

Abstract Magnetic gels and elastomers consist of magnetic or magnetizable colloidal particles embedded in an elastic polymeric matrix. Outstanding properties of these materials comprise reversible changes in their mechanical stiffness or magnetostrictive distortions under the influence of external magnetic fields. To understand such types of overall material behavior from a theoretical point of view, it is essential to characterize the substances starting from the discrete colloidal particle level. It turns out that the macroscopic material response depends sensitively on the mesoscopic particle arrangement. We have utilized and developed several theoretical approaches to this end, allowing us both to reproduce experimental observations and to make theoretical predictions. Our hope is that both these paths help to further stimulate the interest in these fascinating materials.

scholarly journals The contribution of the Italian residents in neurology to the COVID-19 crisis: admirable generosity but neurological training remains their priority

2021 ◽  
Author(s):  
Cristina Tassorelli ◽  
Vincenzo Silani ◽  
Alessandro Padovani ◽  
Paolo Barone ◽  
Paolo Calabresi ◽  
...  
Keyword(s):  
Clinical Training ◽  
Real Life ◽  
Healthcare Management ◽  
Point Of View ◽  
Research Activity ◽  
High Quality ◽  
Research Activities ◽  
Italian Regions ◽  
Training And Research

Abstract Background The coronavirus disease 2019 (COVID-19) pandemic has severely impacted the Italian healthcare system, underscoring a dramatic shortage of specialized doctors in many disciplines. The situation affected the activity of the residents in neurology, who were also offered the possibility of being formally hired before their training completion. Aims (1) To showcase examples of clinical and research activity of residents in neurology during the COVID-19 pandemic in Italy and (2) to illustrate the point of view of Italian residents in neurology about the possibility of being hired before the completion of their residency program. Results Real-life reports from several areas in Lombardia—one of the Italian regions more affected by COVID-19—show that residents in neurology gave an outstanding demonstration of generosity, collaboration, reliability, and adaptation to the changing environment, while continuing their clinical training and research activities. A very small minority of the residents participated in the dedicated selections for being hired before completion of their training program. The large majority of them prioritized their training over the option of earlier employment. Conclusions Italian residents in neurology generously contributed to the healthcare management of the COVID-19 pandemic in many ways, while remaining determined to pursue their training. Neurology is a rapidly evolving clinical field due to continuous diagnostic and therapeutic progress. Stakeholders need to listen to the strong message conveyed by our residents in neurology and endeavor to provide them with the most adequate training, to ensure high quality of care and excellence in research in the future.

scholarly journals From the Quasi-Total Strong Differential to Quasi-Total Italian Domination in Graphs

Symmetry ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1036
Author(s):  
Abel Cabrera Martínez ◽  
Alejandro Estrada-Moreno ◽  
Juan Alberto Rodríguez-Velázquez
Keyword(s):  
Vertex Cover ◽  
Domination Number ◽  
Theoretical Computer Science ◽  
Discrete Mathematics ◽  
Special Issue ◽  
Total Domination Number ◽  
Theoretical Computer ◽  
Graph Parameters ◽  
Semitotal Domination ◽  
Domination In Graphs

This paper is devoted to the study of the quasi-total strong differential of a graph, and it is a contribution to the Special Issue “Theoretical computer science and discrete mathematics” of Symmetry. Given a vertex x∈V(G) of a graph G, the neighbourhood of x is denoted by N(x). The neighbourhood of a set X⊆V(G) is defined to be N(X)=⋃x∈XN(x), while the external neighbourhood of X is defined to be Ne(X)=N(X)∖X. Now, for every set X⊆V(G) and every vertex x∈X, the external private neighbourhood of x with respect to X is defined as the set Pe(x,X)={y∈V(G)∖X:N(y)∩X={x}}. Let Xw={x∈X:Pe(x,X)≠⌀}. The strong differential of X is defined to be ∂s(X)=|Ne(X)|−|Xw|, while the quasi-total strong differential of G is defined to be ∂s*(G)=max{∂s(X):X⊆V(G)andXw⊆N(X)}. We show that the quasi-total strong differential is closely related to several graph parameters, including the domination number, the total domination number, the 2-domination number, the vertex cover number, the semitotal domination number, the strong differential, and the quasi-total Italian domination number. As a consequence of the study, we show that the problem of finding the quasi-total strong differential of a graph is NP-hard.

Adherence, Persistence, and Effectiveness in Real Life. Multicenter Long-Term Study on the Use of Pirfenidone and Nintedanib in the Treatment of Idiopathic Pulmonary Fibrosis

2021 ◽  
pp. 089719002110086
Author(s):  
Fiorenzo Santoleri ◽  
Luigia Auriemma ◽  
Antonella Spacone ◽  
Stefano Marinari ◽  
Fabio Esposito ◽  
...  
Keyword(s):  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Pharmacological Study ◽  
Functional Decline ◽  
Real Life ◽  
Point Of View ◽  
Response To Treatment ◽  
First Year ◽  
Long Term Study ◽  
Second Year

Background: In the treatment of idiopathic pulmonary fibrosis (IPF), nintedanib and pirfenidone, with their different mechanisms of action, lead to a reduction in the rate of progression of the fibrosis process measured by the reduction of functional decline, and, in particular, the decrease in forced vital capacity (FVC) and of the diffusion capacity of the lungs for carbon monoxide (DLCO). The objective of this study was to analyze real-life adherence, persistence and efficacy in the use of pirfenidone and nintedanib in the treatment of IPF. Methods: A non-interventional multicenter retrospective observational pharmacological study in real-life treat-ment at 1 and 2 years was conducted. Furthermore, we analyzed the levels of FVC and DLCO at 6 and 12 months, respectively, from the start of treatment. Results: We identified 144 patients in the period between January 2013 and April 2019. From the point of view of adherence, there is no difference between the two drugs, even though patients who used pirfenidone had increasingly higher values: 0.90 vs 0.89, in the first year, and 0.91 vs 0.84, in the second year. In the first year of treatment, the percentage of persistent patients was 67% and 76%, while in the second year, it dropped to 47% and 53% for pirfenidone and nintedanib, respectively. Conclusion: The stratification of the adherence values as a function of the response to treatment in terms of FVC at 12 months for both study drugs showed that patients with optimal response scored adherence of more than 90%.

A Test Sheet Optimization Approach to Supporting Web-based Learning Diagnosis Using Group Testing Methods

2017 ◽  
Vol 7 (4) ◽  
pp. 1-23
Author(s):  
Chu-Fu Wang ◽  
Chih-Lung Lin ◽  
Gwo-Jen Hwang ◽  
Sheng-Pin Kung ◽  
Shin-Feng Chen
Keyword(s):  
Test Item ◽  
Group Testing ◽  
Diagnostic System ◽  
Point Of View ◽  
Optimization Approach ◽  
Exposure Rate ◽  
Web Based ◽  
Item Exposure ◽  
Test Items ◽  
Doubling Method

Assessment can help teachers to examine the effectiveness of teaching and to diagnose the unfamiliar basic concepts (or attributes) of students within the testing scope. A web-based adaptive testing and diagnostic system can achieve the above objective efficiently and correctly. From a diagnostic point of view, the major concerns are to diagnose whether or not an examinee has learned each basic concept well in the testing scope, while also limiting the number of test items used (the testing length) to as few as possible, which will be directly related to the patience of the examinee. In this paper, we consider a test item selecting optimization diagnostic problem to reveal the mastery profile of an examinee (that is, to diagnose each basic concept's learning status (well learned/unfamiliar) in the testing scope) with a short testing length and a limited test item exposure rate. This paper uses the techniques of Group Testing theory for the design of our test item selecting algorithm. Two test item selecting strategies, the bisecting method and the doubling method, are proposed. The effectiveness of the proposed methods was evaluated by experimental simulations. The results show that both of the proposed algorithms use fewer test items and a limited test item exposure rate compared to the conventional methods.

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