Search results for " Management Science and Operations Research"
showing 10 items of 11 documents
The Hierarchical Mixed Rural Postman Problem: Polyhedral analysis and a branch-and-cut algorithm
2017
[EN] The Hierarchical Mixed Rural Postman Problem is defined on a mixed graph where arcs and edges that require a service are divided into clusters' that have to be serviced in a hierarchical order. The problem generalizes the Mixed Rural Postman Problem and thus is NP-hard. In this paper, we provide a polyhedral analysis of the problem and propose a branch-and-cut algorithm for its solution based on the introduced classes of valid inequalities. Extensive computational experiments are reported on benchmark instances. The exact approach allows to find the optimal solutions in less than 1 hour for instances with up to 999 vertices, 2678 links, and five clusters.
Expectations as Reference Points: Field Evidence from Professional Soccer
2015
We show that professional soccer players and their coaches exhibit reference-dependent behavior during matches. Controlling for the state of the match and for unobserved heterogeneity, we show on a minute-by-minute basis that players breach the rules of the game, measured by the referee’s assignment of cards, significantly more often if their teams are behind the expected match outcome, measured by preplay betting odds of large professional bookmakers. We further show that coaches implement significantly more offensive substitutions if their teams are behind expectations. Both types of behaviors impair the expected ultimate match outcome of the team, which shows that our findings do not si…
Groupthink and Project Performance: The Influence of Personal Traits and Interpersonal Ties
2015
Contains fulltext : 166103.pdf (Publisher’s version ) (Closed access) This study explores whether the negative impact of “groupthink concurrence-seeking behavior” (GTB) on business process reengineering (BPR) projects is affected by group members personal traits and interpersonal ties within the group. To this purpose we conduct and present the results of a longitudinal controlled field experiment over 18 BPR projects lasting 3 months and involving 18 teams comprising 71 first-year MBA students. The main contribution of this study is twofold. First, we explicitly consider and measure the core construct of groupthink phenomenon: that is, GTB. Existing organizational behavior literature has, …
A branch-and-cut algorithm for the Team Orienteering Problem
2017
The Team Orienteering Problem aims at maximizing the total amount of profit collected by a fleet of vehicles while not exceeding a predefined travel time limit on each vehicle. In the last years, several exact methods based on different mathematical formulations were proposed. In this paper, we present a new two-index formulation with a polynomial number of variables and constraints. This compact formulation, reinforced by connectivity constraints, was solved by means of a branch-and-cut algorithm. The total number of instances solved to optimality is 327 of 387 benchmark instances, 26 more than any previous method. Moreover, 24 not previously solved instances were closed to optimality.
Factors in the global assimilation of collaborative information technologies: an exploratory investigation in five regions
2008
The diffusion of innovation theory is deployed to investigate the global assimilation of collaborative information technologies (CITs). Based on the concepts of IT acquisition and utilization, an assimilation framework is presented to highlight four states (limited, focused, lagging, and pervasive) that capture the assimilation of conferencing and groupware CITs. Data collected from 538 organizations in the United States, Australia, Hong Kong, Norway, and Switzerland are aggregated and analyzed to explore assimilation patterns and the influence of decision-making pattern, functional integration, promotion of collaboration, organization size, and IT function size on the assimilation of CITs.…
From the crowd to the market: The role of reward-based crowdfunding performance in attracting professional investors
2017
Abstract We focus on new technology-based entrepreneurial ventures engaging in reward-based crowdfunding and examine the effect of their performance in such funding channel on the likelihood of securing subsequent funding from professional investors. We also study how this effect is influenced by the presence of patents granted for the new product idea and the entrepreneur social capital. Results from a sample of technology projects launched on Kickstarter demonstrate that pledging a higher amount of money in crowdfunding can ignite professional investors’ interest and thus help secure subsequent funding. However, this positive evidence is effective only when complemented by the presence of…
The effect of inventory record inaccuracy in information exchange supply chains
2015
Abstract The goal of this paper is to quantify the impact of Inventory Record Inaccuracy on the dynamics of collaborative supply chains, both in terms of operational performance (i.e. order and inventory stability), and customer service level. To do so, we model an Information Exchange Supply Chain under shrinkage errors in the inventory item recording activity of their nodes, present the mathematical formulation of such supply chain model, and conduct a numerical simulation assuming different levels of errors. Results clearly show that Inventory Record Inaccuracy strongly compromises supply chain stability, particularly when moving upwards in the supply chain. Important managerial insights…
Portfolio diversification in the sovereign credit swap markets
2018
We develop models for portfolio diversification in the sovereign credit default swaps (CDS) markets and show that, despite literature findings that sovereign CDS spreads are affected by global factors, there is sufficient idiosyncratic risk to be diversified. However, we identify regime switching in the times series of CDS spreads and spread returns, and the optimal diversified strategies can be regime dependent. The developed models trade off the CVaR risk measure against expected return, consistently with the statistical properties of spreads. We consider three investment strategies suited for different CDS market participants: for investors with long positions, speculators that hold unco…
Game Theoretic Decentralized Feedback Controls in Markov Jump Processes
2017
This paper studies a decentralized routing problem over a network, using the paradigm of mean-field games with large number of players. Building on a state-space extension technique, we turn the problem into an optimal control one for each single player. The main contribution is an explicit expression of the optimal decentralized control which guarantees the convergence both to local and to global equilibrium points. Furthermore, we study the stability of the system also in the presence of a delay which we model using an hysteresis operator. As a result of the hysteresis, we prove existence of multiple equilibrium points and analyze convergence conditions. The stability of the system is ill…
The directed profitable rural postman problem with incompatibility constraints
2017
[EN] In this paper, we study a variant of the directed rural postman problem (RPP) where profits are asso- ciated with arcs to be served, and incompatibility constraints may exist between nodes and profitable arcs leaving them. If convenient, some of the incompatibilities can be removed provided that penalties are paid. The problem looks for a tour starting and ending at the depot that maximizes the difference between collected profits and total cost as sum of traveling costs and paid penalties, while satisfying remaining incompatibilities. The problem finds application in the domain of road transportation service, and in particular in the context of horizontal collaboration among carriers …