Search results for " operations"

Pandemic Prevention and Personality Psychology: Gender Differences in Preventive Health Behaviors during COVID-19 and the Roles of Agreeableness and …

2022

One of the greatest public health crises in recent times, the COVID-19 pandemic, has come with a myriad of challenges in terms of health communication and public cooperation to prevent the spread of the disease. Understanding which are the key determinants that make certain individuals more cooperative is key in effectively tackling pandemics and similar future challenges. In the present study (N = 800), we investigated whether gender differences in compliance with preventive health behaviors (PHB) at the onset of the COVID-19 pandemic could be established, and, if so, whether the personality traits of agreeableness and conscientiousness could help explain this presumed relationship. Consis…

Sustainable Farming Practices, Awareness, and Behavior in Small Farms in Brazil

2021

This paper investigates the relationship between the use of digital and non-digital sources of information on sustainable farming practices, institutional pressure and adoption of such practices by farmers in Brazilian semi-arid lands. The research uses a model based on the theory of reasoned action (TRA) and the institutional theory. Our results for a sample of 100 Brazilian farmers show that non-digital sources of information and ‘Coercive’ and ‘Normative’ pressures have a positive impact on farmers’ attitude towards and actual adoption of sustainable farming practices. However, digital sources of information such as TV and Radio do not play a significant role. In addition, pro-environmen…

Estimating economic severity of Air Traffic Flow Management regulations

2021

The development of trajectory-based operations and the rolling network operations plan in European air traffic management network implies a move towards more collaborative, strategic flight planning. This opens up the possibility for inclusion of additional information in the collaborative decision-making process. With that in mind, we define the indicator for the economic risk of network elements (e.g., sectors or airports) as the expected costs that the elements impose on airspace users due to Air Traffic Flow Management (ATFM) regulations. The definition of the indicator is based on the analysis of historical ATFM regulations data, that provides an indication of the risk of accruing dela…

Geometric interpretation of the optimality conditions in multifacility location and applications

1991

Geometrical optimality conditions are developed for the minisum multifacility location problem involving any norm. These conditions are then used to derive sufficient conditions for coincidence of facilities at optimality; an example is given to show that these coincidence conditions seem difficult to generalize.

Upper and lower generalized factoraggregations based on fuzzy equivalence relation

2014

We develop the concept of a general factoraggre-gation operator introduced by the authors on the basis of an equivalence relation and applied in two recent papers for analysis of bilevel linear programming solving parameters. In the paper this concept is generalized by using a fuzzy equivalence relation instead of the crisp one. By using a left-continuous t-norm and its residuum we define and investigate two modifications of such generalized construction: upper and lower generalized factoraggregations. These generalized factoraggregations can be used for construction of extensional fuzzy sets.

Fibred Categories and the Six Functors Formalism

2019

In Section 1, we introduce the basic language used in this book, the so-called premotivic categories and their functoriality. This is an extension of the classical notion of fibered categories. They appear with different categorical structures. In Section2, the language of premotivic categories is specialized to that of triangulated categories and to algebraic geometry. We introduce several axioms of such categories which ultimately will lead to the full six functors formalism. An emphasis is given on the study of the main axioms, with a special care about the so-called localization axiom. Then in Section 3, the general theory of descent is formulated in the language of premotivic model cat…

GRASP with exterior path-relinking and restricted local search for the multidimensional two-way number partitioning problem

2017

In this work, we tackle multidimensional two-way number partitioning (MDTWNP) problem by combining GRASP with Exterior Path Relinking. In the last few years, the combination of GRASP with path relinking (PR) has emerged as a highly effective tool for finding high-quality solutions for several difficult problems in reasonable computational time. However, in most of the cases, this hybridisation is limited to the variant known as interior PR. Here, we couple GRASP with the "exterior form" of path relinking and perform extensive experimentation to evaluate this variant. In addition, we enhance our GRASP with PR method with a novel local search method specially designed for the MDTWNP problem. …

An environment based approach for the ant colony convergence

2020

Abstract Ant colony optimization (ACO) algorithms are a bio inspired solutions which have been very successful in combinatorial problem solving, also known as NP-hard problems, including transportation system optimization. As opposed to exact methods, which could give the best results of a tested problem, this meta-heuristics is based on the stochastic logic but not on theoretical mathematics demonstration (or only on certain well defined applications). According to this, the weak point of this meta-heuristics is his convergence, its termination condition. We can finds many different termination criteria in the scientific literature, yet most of them are costly in resources and unsuitable f…

Addressing Dendritic Cells for Anticancer Immunity

2014

Scenario optimization asset and liability modelling for individual investors

2006

We develop a scenario optimization model for asset and liability management of individual investors. The individual has a given level of initial wealth and a target goal to be reached within some time horizon. The individual must determine an asset allocation strategy so that the portfolio growth rate will be sufficient to reach the target. A scenario optimization model is formulated which maximizes the upside potential of the portfolio, with limits on the downside risk. Both upside and downside are measured vis- `a-vis the goal. The stochastic behavior of asset returns is captured through bootstrap simulation, and the simulation is embedded in the model to determine the optimal portfolio. …