• Networks in professional groups: a matter of connection or self-excile?

      Boros, Smaranda; Van Gorp, Lore (Team Performance Management: An International Journal, 2017)
      Purpose - Integrating predictions of social exchange theory and implicit social cognition, this paper aims to investigate mechanisms of co-evolution between professional and personal support networks in a professional, non-hierarchical setting. Design/methodology/approach - The study covers simultaneously people's behaviours and their subjective interpretations of them in a cross-lagged network design in a group of 65 MBAstudents. Findings - Results show that people build on their professional support network to develop personal support relations. People who have a high status in the professional support network appear to be afraid to lose them by asking too many others for personal support and people with a low status in the professional support network seemalso be reluctant to ask many others for personal support. Practical implications - Although personal support is a key social mechanism facilitating individual well-being and organizational success, support in the workplace often remains limited to professional topics. This research shows why people hesitate to expand their networks in professional settings and to what extent their fears have a basis in reality. Originality/value - It goes beyond predictions of social exchange theory which inform most network evolution studies and tap into implicit social cognition predictions to expand the explanatory power of the hypotheses. The study's network analysis takes into account both behaviours and social perceptions. The sample is a non-hierarchical professional group which allows a more ecological observation of how hierarchies are born in social groups.
    • Networks shaping open innovation

      Vanhaverbeke, Wim (2006)
    • Neue Technologien im öffentlichen Sektor: Bürgerinnen und Bürger haben nur geringe Erwartungen

      Fischer, Caroline; Willems, Jurgen; Van den Bergh, Joachim (VM Verwaltung & Management, 2021)
      Aktuelle technologische Entwicklungen (z.B. künstliche Intelligenz) führen immer wieder zu Debatten, wie diese sinnvoll für die öffentliche Verwaltung genutzt werden können. Die Verwaltung selbst und entsprechende Expertinnen und Experten diskutieren mögliche positive Wirkungen auch in Bezug auf Werte, wie Effizienz, Transparenz oder Fairness. Diese Studie untersucht, ob Bürgerinnen und Bürger von der Anwendung dieser Technologien in der öffentlichen Verwaltung ebensolche Wirkungen ebenso erwarten. Dabei wird auch analysiert, ob eine andere Erwartungshaltung als bei gewinnorientierten Unternehmen besteht. Die Befragungsergebnisse (N=1.577) zeigen, dass weder negative noch positive Erwartungen in Bezug auf Wirkungen dieser Technologien bestehen, das gilt für öffentliche wie für die privatwirtschaftliche Leistungserbringung. Es wird diskutiert, ob die Ergebnisse in der bisher mangelnden Anwendung der untersuchten Technologien begründet liegen oder aus einer unzureichenden Kommunikation mit und Einbindung von Bürgerinnen und Bürgern in entsprechende Planungs- und Implementationsprozesse resultieren.
    • New actors and business models for the integration of electric vehicles

      Momber, Ilan; Gómez, Tómas; Rivier, Michel; Cossent, R. (2011)
    • A new algorithm for resource-constrained project scheduling with breadth and depth of skills

      Snauwaert, Jakob; Vanhouke, Mario (European Journal of Operational Research, 2021)
      This paper addresses a multi-skilled extension of the resource-constrained project scheduling problem (RCPSP). Although a handful of papers dealt with the multi-skilled RCPSP (MSRCPSP), little to no attention is given to the ideal levels of skills for multi-skilled resources. In this paper, skills are measured along two dimensions known as breadth and depth. In a project environment, the breadth of a resource is perceived as the amount of skills an employee masters. The depth of a skill is the efficiency level at which work can be performed by a resource that masters that skill. The MSRCPSP with breadth and depth consists of scheduling activities with skill requirements and assigning multi-skilled resources to those activities. To be able to efficiently solve the MSRCPSP, a genetic algorithm is developed. Using the created activity schedules and resources assignments, the best workforce characteristics are analysed. Key aspects in this analysis are the breadth and depth. The problem-specific procedure combines a new representation, a new crossover and tailor-made local searches. Computational experiments measure the impact of different multi-skilled resources and their efficiency levels on the makespan of the project.
    • New computational results for the discrete time/cost trade-off problem with time-switch constraints

      Vanhoucke, Mario (2002)
      Recently, time-switch constraints have been introduced in literature by Yang and Chen (2000). Basically, these constraints impose a specified starting time on the project activities and force them to be inactive during specified time periods. This type of constraints have been incorporated into the well-known discrete time/cost trade-off problem in order to cope with day, night and weekend shifts. In this paper, we propose a new branch-and-bound algorithm which outperforms the previous one by Vanhoucke et al. (2002a). The procedure makes use of a lower bound calculation for the discrete time/cost trade-off problem (without time-switch constraints). The procedure has been coded in Visual C++, version 6.0 under Windows 2000 and has been validated on a randomly generated problem set. Keywords: Project Management, CPM, Time/cost trade-off problem, Time-switch constraints.
    • New computational results for the nurse scheduling problem: A scatter search algorithm

      Maenhout, Broos; Vanhoucke, Mario (2006)
      In this paper, we present a scatter search algorithm for the well-known nurse scheduling problem (NSP). This problem aims at the construction of roster schedules for nurses taking both hard and soft constraints into account. The objective is to minimize the total preference cost of the nurses and the total penalty cost from violations of the soft constraints. The problem is known to be NP-hard. The contribution of this paper is threefold. First, we are, to the best of our knowledge, the first to present a scatter search algorithm for the NSP. Second, we investigate two different types of solution combination methods in the scatter search framework, based on four different cost elements. Last, we present detailed computational experiments on a benchmark dataset presented recently, and solve these problem instances under different assumptions. We show that our procedure performs consistently well under many different circumstances, and hence, can be considered as robust against case-specific constraints. Keywords: meta-heuristics, scatter search, nurse scheduling
    • New computational results for the nurse scheduling problem: a scatter search algorithm

      Maenhout, Broos; Vanhoucke, Mario (Lecture notes in Computer Science, 2006)
    • New computational results on the discrete time/cost trade-off problem in project networks

      Demeulemeester, Erik; De Reyck, B.; Foubert, Bram; Herroelen, Willy; Vanhoucke, Mario (Journal of the Operational Research Society, 1998)
      A description is given of a new exact procedure for the discrete time/cost trade-off problem in deterministic activity-on-the-arc networks of the CPM type, where the duration of each activity is a discrete, nonincreasing function of the amount of a single resource (money) committed to it. The objective is to construct the complete and efficient time/cost profile over the set of feasible project durations. The procedure uses a horizon-varying approach based on the iterative optimal solution of the problem of minimizing the sum of the resource use over all activities subject to the activity precedence constraints and a project deadline. The optimal solution is derived using a branch-and-bound procedure.
    • New concepts, new practices - The business implications of sustainable development as a new paradigm

      Roome (+), Nigel (2012)
      Religious organisations are major investors with sometimes substantial investment volumes. An important question for them is how to make investments in, and to earn returns from, companies and activities that are consistent with their religious beliefs or that even support these beliefs. Religious organisations have pioneered responsible investment. Yet little is known about their investment attitudes. This article addresses this gap by studying faith consistent investing. Based on a survey complemented by interviews, we investigate religious organisations’ attitudes towards responsible investment including opinions, practices and the impediments for implementing faith consistent investing. Although our results cannot be generalised because of the non-random character of our sample, six main characteristics of faith consistent investing are drawn: investing is not perceived as being in contradiction with religious values, religious values are important drivers, there is a strong community around faith consistent investing, religious investors are pioneering impact investing, implementing faith consistent investing is not without difficulties, and practices vary across regions. The survey also reveals that faith consistent investing has many commonalities with secular responsible investors.
    • A new cross-validation technique to evaluate quality of recommender systems

      Ignatov, Dmitry I.; Poelmans, Jonas; Dedene, Guido; Viaene, Stijn (2012)
      The topic of recommender systems is rapidly gaining interest in the user-behaviour modeling research domain. Over the years, various recommender algorithms based on different mathematical models have been introduced in the literature. Researchers interested in proposing a new recommender model or modifying an existing algorithm should take into account a variety of key performance indicators, such as execution time, recall and precision. Till date and to the best of our knowledge, no general cross-validation scheme to evaluate the performance of recommender algorithms has been developed. To fill this gap we propose an extension of conventional cross-validation. Besides splitting the initial data into training and test subsets, we also split the attribute description of the dataset into a hidden and visible part. We then discuss how such a splitting scheme can be applied in practice. Empirical validation is performed on traditional user-based and item-based recommender algorithms which were applied to the MovieLens dataset.