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A multi-start simheuristic for the stochastic two-dimensional vehicle routing problem

The two-dimensional vehicle routing problem (2L-VRP) is a realistic extension of the classical vehicle routing problem where customers’ demands are composed by sets of non-stackable items. Examples of such problems can be found in many real-life applications, e.g. furniture or industrial machinery transportation. Often, these real-life instances have to deal with uncertainty in many aspects of the problem, such as variable traveling times due to traffic conditions or customers availability. We present a hybrid simheuristic algorithm that combines biased-randomized routing and packing heuristics within a multi-start framework. Monte Carlo simulation is used to deal with uncertainty at different stages of the search process. With the goal of minimizing total expected cost, we use this methodology to solve a set of stochastic instances of the 2L-VRP with unrestricted oriented loading. Our results show that accounting for systems variability during the algorithm search yields more robust solutions with lower expected costs.

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A multi-start simheuristic for the stochastic two-dimensional vehicle routing problem

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A shipping simulation through pathfinding: SEL within the MSP Challenge simulation platform

The authors present the design of the shipping simulation SEL and its integration in the MSP Challenge Simulation Platform. This platform is designed to give policymakers and planners insight into the complexity of Maritime Spatial Planning (MSP) and can be used for interactive planning support. It uses advanced game technology to link real geo- and marine data with simulations for ecology, energy and shipping. The shipping sector is an important economic sector with influential stakeholders. SEL calculates the (future) impact of MSP decisions on shipping routes. This is dynamically shown in key performance indicators (e.g. route efficiencies) and visualised in heat maps of ship traffic. SEL uses a heuristic-based graph-searching algorithm to find paths from one port to another during each simulated month. The performance of SEL was tested for three sea basins: the firth of Clyde, Scotland (smallest), North Sea (with limited data) and Baltic Sea regions (largest, with most complete data). The behaviour of the model is stable and valid. SEL takes between 4 and 17 seconds to generate the desired monthly output. Experiences in 20 sessions with 302 planners, stakeholders and students indicate that SEL is a valuable addition to MSP Challenge, and thereby to MSP.

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A shipping simulation through pathfinding: SEL within the MSP Challenge simulation platform

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Integrated Optimization of arrival, departure, and surface operations

Airports and surrounding airspaces are limited in terms of capacity and represent the major bottleneck in the air traffic management system. This paper proposes a two level model to tackle the integrated optimization problem of arrival, departure, and surface operations. The macroscopic level considers the terminal airspace management for arrivals and departures and airport capacity management, while the microscopic level optimizes surface operations and departure runway scheduling. An adapted simulated annealing heuristic combined with a time decomposition approach is proposed to solve the corresponding problem. Computational experiments performed on real-world case studies of Paris Charles De-Gaulle airport, show the benefits of this integrated approach.

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Integrated Optimization of arrival, departure, and surface operations

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Mediating in Hierarchical workplace conflicts

Mediators generally find mediation of hierarchical workplace conflicts difficult, as it often involves structural power imbalances. This dissertation seeks to increase knowledge of how hierarchical conflict affects how parties and mediators perceive mediation across dyads and across time. Three questions are central to this: (a) How effective in the long-term is the mediation of hierarchical workplace conflicts? (b) How does perceived situational power in supervisor-subordinate dyads relate to mediation effectiveness? (c) Do supervisors and subordinates differ in their emotional experiences during mediation, and are mediators able to perceive these emotions accurately? To answer these questions, we rely on the literature on power, emotions, mediation, and conflict management. We introduce our research via a heuristic model (chapter one). We then present our quantitative empirical research in three chapters based on survey data we collected from supervisors, subordinates, and

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Mediating in Hierarchical workplace conflicts

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Toward a theory of affordable loss

Although dozens of empirical studies have been published on effectuation as a whole, much work remains to be done on elaborating each principle in more depth. Based on an exploratory study of seven ventures from the Caribbean island of Curacao, this paper develops an elaborated process model of the affordable loss heuristic in effectuation. The model breaks affordable loss into two components—ability and willingness, and connects these to the concept of loss aversion from prospect theory. Furthermore, these components are encapsulated in a process involving identity, affect, and resourcefulness leading to the entry-stage entrepreneurial investment decision.

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Heuristics in financial decision-making: the selection of SME financing by advisers in an increasingly diverse market

PurposeIn order to better understand how heuristics are used in practice, the authors explore what type of heuristics is used in the managerial domain of financial advisors to small and medium-sized enterprises (SMEs) and what influences the shaping of these heuristics. In doing so, the authors detect possible fast-and-frugal heuristics in day-to-day decision-making of independent financial advisers who help owners of SMEs to acquire capital (e.g. loans, factoring, leasing and equity).Design/methodology/approachThe authors inductively assessed the work of financial advisers of SMEs. Based on group discussions, the authors drew up a semi-structured interview-protocol with descriptive questions about how financial advisers come to a deal for their clients. The interviews of 19 professionals were analysed by relating them to the theory of fast-and-frugal heuristics.FindingsWithin their decision-making, advisers estimate the likelihood of acceptance by a few financial providers they know well in their personal network with a strong bias towards traditional banking products, although there are a large number of alternatives on the Dutch market. “Less is more” seems to be a relevant principle when defined as satisficing. Heuristics help advisers to deal with behavioural and economic limitations. Also, the authors have found that client interaction, previous working experience and the company the adviser is working for influences the shaping of the simple rules the adviser is using.Research limitations/implicationsThe study shows how difficult it is to understand the ecological rationality of a certain group of professionals and to understand the “less is more” principle. Financial advisers to SMEs use cognitive shortcuts and simple rules to advise SME-owners, based on previous experiences, but it is difficult to determine whether that leads to the same or even better solutions for them and their clients than using probability theory and financial optimisation models. Within heuristics, satisficing seems to be a dominant mechanism. Here, heuristics help advisers in recognising possibilities by searching for similarities between a current financing case and previous experiences. The data suggests that if “less is more” is defined as satisficing for one or more stakeholders involved, the principle dominates the decision making of financial advisers of SME's.Practical implicationsThe authors suggest the relevance of a behavioural approach to finance by assessing the day-to-day decisions of financial advisers of SMEs. Also, the authors suggest that financial advisers are guided by previous experiences, and they do not fully assess a wide range of options in their work but need shortcuts to fulfil the needs of their clients.Originality/valueThe study comes close to day-to-day decision-making in finance by assessing how professionals make decisions. The authors try to understand types of heuristics in relation with “ecological rationality” and the less is more principle. The authors assess financial advisers of SME-companies, a group that has gotten little research attention until now. The influence of client interaction and of the company the adviser is working for is remarkable in the shaping of the advisers' simple rules.

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Heuristics in financial decision-making: the selection of SME financing by advisers in an increasingly diverse market

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· [Review of: M. Black, Staley, D.J. (2007). A heuristic for visual thinking in history. International Journal of Social Education 22. pp. 24-42]

Historici denken traditioneel gezien in woorden. Daarbij zijn teksten als ‘primaire bronnen’ favoriet. Sterker nog, na een onderzoek vinden ze alleen het gene wat geschreven is belangrijk. Deze vorm van representatie (boeken en artikelen) is bij historici het meest geliefd. Zelfs bij presentaties zijn historici geneigd hun werk voor te lezen. Pas de afgelopen 20 jaar nemen historici de film als een representatievorm van de geschiedenis serieus. Toch meer in de vorm van studie en kritiek naar films door anderen gemaakt. Films worden niet vaak gekozen door historici om het verleden weer te geven. Het beeld van de historicus is dat van een schrijver. Hier kunnen we een tweedeling in maken, namelijk de literaire schrijver voor het grote publiek en de historicus met een wetenschappelijke en analytische stijl van schrijven. Staley geeft aan dat deze houding effecten heeft op de wijze waarop wij geschiedenis doorgeven aan onze studenten / leerlingen. Bij het toetsen worden vaak geschreven papers en essays gevraagd, daarnaast worden natuurlijk de tentamens afgenomen. De studenten leren te denken in zinnen, paragrafen en narratieve opstellen. De historici zitten in een tekstuele cultuur en dat in een tijd waarin multimedia zijn hoogtij viert. Staley heeft in het kader van zijn onderzoeken al vele geschiedenisdocenten gesproken. Wat hem opviel was dat een groot aantal docenten hun vraagtekens bij de kwaliteit van de multimediaprojecten plaatsten. In de praktijk betekende dit dat veel docenten multimedia liever achterwege hielden, vanwege de vorm en inhoud die in hun belevingswereld niet aansloot bij de academische cultuur.

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· [Review of: M. Black, Staley, D.J. (2007). A heuristic for visual thinking in history. International Journal of Social Education 22. pp. 24-42]

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Heuristic Coordination in Cooperative Multi-Agent Reinforcement Learning

Key to reinforcement learning in multi-agent systems is the ability to exploit the fact that agents only directly influence only a small subset of the other agents. Such loose couplings are often modelled using a graphical model: a coordination graph. Finding an (approximately) optimal joint action for a given coordination graph is therefore a central subroutine in cooperative multi-agent reinforcement learning (MARL). Much research in MARL focuses on how to gradually update the parameters of the coordination graph, whilst leaving the solving of the coordination graph up to a known typically exact and generic subroutine. However, exact methods { e.g., Variable Elimination { do not scale well, and generic methods do not exploit the MARL setting of gradually updating a coordination graph and recomputing the joint action to select. In this paper, we examine what happens if we use a heuristic method, i.e., local search, to select joint actions in MARL, and whether we can use outcome of this local search from a previous time-step to speed up and improve local search. We show empirically that by using local search, we can scale up to many agents and complex coordination graphs, and that by reusing joint actions from the previous time-step to initialise local search, we can both improve the quality of the joint actions found and the speed with which these joint actions are found.

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Judging the Wrongness of Firms in Social Media Firestorms

Social media firestorms pose a significant challenge for firms in the digital age. Tackling firestorms is difficult because the judgments and responses from social media users are influenced by not only the nature of the transgressions but also by the reactions and opinions of other social media users. Drawing on the heuristic-systematic information processing model, we propose a research model to explain the effects of social impact (the heuristic mode) and argument quality and moral intensity (the systematic mode) on perceptions of firm wrongness (the judgment outcome) as well as the effects of perceptions of firm wrongness on vindictive complaining and patronage reduction. We adopted a mixed methods approach in our investigation, including a survey, an experiment, and a focus group study. Our findings show that the heuristic and systematic modes of information processing exert both direct and interaction effects on individuals’ judgment. Specifically, the heuristic mode of information processing dominates overall and also biases the systematic mode. Our study advances the literature by offering an alternative explanation for the emergence of social media firestorms and identifying a novel context in which the heuristic mode dominates in dual information processing. It also sheds light on the formulation of response strategies to mitigate the adverse impacts resulting from social media firestorms. We conclude our paper with limitations and future research directions.

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Zoekresultaten

Producten 293

A multi-start simheuristic for the stochastic two-dimensional vehicle routing problem

A shipping simulation through pathfinding: SEL within the MSP Challenge simulation platform

Integrated Optimization of arrival, departure, and surface operations

Mediating in Hierarchical workplace conflicts

Toward a theory of affordable loss

Heuristics in financial decision-making: the selection of SME financing by advisers in an increasingly diverse market

· [Review of: M. Black, Staley, D.J. (2007). A heuristic for visual thinking in history. International Journal of Social Education 22. pp. 24-42]

Heuristic Coordination in Cooperative Multi-Agent Reinforcement Learning

Judging the Wrongness of Firms in Social Media Firestorms

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Electric mobility business model database for business model innovation

Naar een gedragsperspectief op besluitvorming van financieel adviseurs

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