Search results for "Heuristic"

A matheuristic for the Team Orienteering Arc Routing Problem

2015

In the Team OrienteeringArc Routing Problem (TOARP) the potential customers are located on the arcs of a directed graph and are to be chosen on the basis of an associated profit. A limited fleet of vehicles is available to serve the chosen customers. Each vehicle has to satisfy a maximum route duration constraint. The goal is to maximize the profit of the served customers. We propose a matheuristic for the TOARP and test it on a set of benchmark instances for which the optimal solution or an upper bound is known. The matheuristic finds the optimal solutions on all, except one, instances of one of the four classes of tested instances (with up to 27 vertices and 296 arcs). The average error o…

Performance of Understanding: Pragmatics and Fast and Frugal Heuristics

2019

What determines the meaning of an utterance is a logical matter and as such must be treated independently of the bio-cognitive constraints that operate in our bodies. This thesis, whose great supporter was Frege, implies a clear notion of rationality that seems not to bear comparison with what we know on the limits of our rationality. Various theories (Kahneman and Tversky 1983; Gigerenzer et al., 1999), thematizing the need to consider our rationality beginning from the bio- cognitive constraints that our body imposes on a mass of information, can be of great utility for facing the problem of what type of rationality operates in phenomena of linguistic understanding (Ferreira and Patson 20…

A heuristic for problem formalization in agent based simulation studies

2015

Agent Based Modeling and Simulation (ABMS) is considered an effective approach for conducting simulation studies in many fields. In order to develop high quality simulation models, methodological approaches are demanded. In such direction we are moving by proposing a heuristic for the formalization of agent based simulation problems. The proposed heuristic is based on some guidelines developed for identifying the main elements of the problem domain description by analysing verbs and their common taxonomy in grammar.

The Random Neural Network Model for the On-line Multicast Problem

2005

In this paper we propose the adoption of the Random Neural Network Model for the solution of the dynamic version of the Steiner Tree Problem in Networks (SPN). The Random Neural Network (RNN) is adopted as a heuristic capable of improving solutions achieved by previously proposed dynamic algorithms. We adapt the RNN model in order to map the network characteristics during a multicast transmission. The proposed methodology is validated by means of extensive experiments.

An Efficient Distributed Algorithm for Generating Multicast Distribution Trees

2005

Multicast transmission may use network resources more efficiently than multiple point-to-point messages; however, creating optimal multicast trees (Steiner Tree Problem in Networks) is prohibitively expensive. For this reason, heuristic methods are generally employed. Conventional centralized Steiner heuristics provide effective solutions, but they are unpractical for large networks, since they require complete knowledge of the network topology. This paper proposes a distributed algorithm for the heuristic solution of the Steiner Tree Problem. The algorithm allows the construction of effective distribution trees using a coordination protocol among the network nodes. The algorithm has been i…

2018

A comprehensive monitoring of fitness, fatigue, and performance is crucial for understanding an athlete's individual responses to training to optimize the scheduling of training and recovery strategies. Resting and exercise-related heart rate measures have received growing interest in recent decades and are considered potentially useful within multivariate response monitoring, as they provide non-invasive and time-efficient insights into the status of the autonomic nervous system (ANS) and aerobic fitness. In team sports, the practical implementation of athlete monitoring systems poses a particular challenge due to the complex and multidimensional structure of game demands and player and te…

A Grid Enabled Parallel Hybrid Genetic Algorithm for SPN

2004

This paper presents a combination of a parallel Genetic Algorithm (GA) and a local search methodology for the Steiner Problem in Networks (SPN). Several previous papers have proposed the adoption of GAs and others metaheuristics to solve the SPN demonstrating the validity of their approaches. This work differs from them for two main reasons: the dimension and the features of the networks adopted in the experiments and the aim from which it has been originated. The reason that aimed this work was namely to assess deterministic and computationally inexpensive algorithms which can be used in practical engineering applications, such as the multicast transmission in the Internet. The large dimen…

Heuristic Algorithm for the Analysis of Fast Field Cycling (FFC) NMR Dispersion Curves

2021

Evaluation of nuclear magnetic relaxation dispersion (NMRD) curves obtained by the fast field cycling nuclear magnetic resonance (FFC-NMR) relaxometry technique is a valuable tool for analyzing the microscopic dynamics of condensed matter systems. However, quantitative data analysis involves several conceptual and practical issues. Moving forward from previous literature approaches, we propose a new analysis method, relying on the elaboration of the inverse integral transform of the NMRD curve. Our approach results in a true heuristic method, able to unambiguously individuate the dynamic domains in the system, thereby avoiding the possible introduction of any element of discretion. The anal…

A Novel Bayesian Network Based Scheme for Finding the Optimal Solution to Stochastic Online Equi-partitioning Problems

2014

A number of intriguing decision scenarios, such as order picking, revolve around partitioning a collection of objects so as to optimize some application specific objective function. In its general form, this problem is referred to as the Object Partitioning Problem (OOP), known to be NP-hard. We here consider a variant of OPP, namely the Stochastic Online Equi-Partitioning Problem (SO-EPP). In SO-EPP, objects arrive sequentially, in pairs. The relationship between the arriving object pairs is stochastic: They belong to the same partition with probability p. From a history of object arrivals, the goal is to predict which objects will appear together in future arrivals. As an additional compl…

Perceived Onset Time of Medical Conditions: The Interplay Between Subjective Fear and Risk in Four Lifestyle Domains

2022

Engaging in unhealthy behaviors (e.g., smoking, drinking) and not engaging in healthy ones (e.g., exercising, consuming fruit and vegetables) are both relatively prevalent among individuals despite the available information about their risks for health. People’s perception of an event’s time course can be used to gauge their risk perception for that event thus casting light on any possible misperception and suggesting directions for health-promoting interventions. This study investigates people’s perception of the time of onset of 5 noncommunicable diseases (e.g., “having high blood pressure”) associated with 4 health-related behaviors: Smoking, drinking, exercising, and eating fruit and v…