Search results for "Operations"
showing 10 items of 1692 documents
Surrogate-assisted evolutionary biobjective optimization for objectives with non-uniform latencies
2018
We consider multiobjective optimization problems where objective functions have different (or heterogeneous) evaluation times or latencies. This is of great relevance for (computationally) expensive multiobjective optimization as there is no reason to assume that all objective functions should take an equal amount of time to be evaluated (particularly when objectives are evaluated separately). To cope with such problems, we propose a variation of the Kriging-assisted reference vector guided evolutionary algorithm (K-RVEA) called heterogeneous K-RVEA (short HK-RVEA). This algorithm is a merger of two main concepts designed to account for different latencies: A single-objective evolutionary a…
Flexible Data Driven Inventory Management with Interactive Multiobjective Lot Size Optimization
2021
We study data-driven decision support and formalise a path from data to decision making. We focus on lot sizing in inventory management with stochastic demand and propose an interactive multi-objective optimisation approach. We forecast demand with a Bayesian model, which is based on sales data. After identifying relevant objectives relying on the demand model, we formulate an optimisation problem to determine lot sizes for multiple future time periods. Our approach combines different interactive multi-objective optimisation methods for finding the best balance among the objectives. For that, a decision maker with substance knowledge directs the solution process with one’s preference inform…
New directions for the biopharma industry in Canada: modelling and empirical findings
2008
PurposeThe main purpose of this study is to identify features and trends shaping the business models currently prevailing in the Canadian biopharma industry, by disaggregating the business model analysis into four key areas: value creation, investment strategy, business strategy, success factorsDesign/methodology/approachResults arise from an empirical fieldwork of qualitative nature, undertaken by the end of 2004, involving deep interviews to a broad variety of key stakeholders of the biopharma industry in the Quebec region, including biopharma firms, large pharma firms, venture capital funds, research centers and recognized experts from consultancy firms and Universities.FindingsBiopharma…
Designing Outcome-Based Performance Management Systems to Assess Policies Impacting on Caesarean Section Rate: An Analysis of the Sicilian Maternity …
2017
The reduction in Caesarean sections (CSs) is widely considered a priority in the public decision makers agenda. Though the World Health Organisation has strongly encouraged countries to implement policies to reduce CSs to 10–15%, after almost thirty years this goal appears still far from its achievement. The literature depicts CS as a multifaceted phenomenon whose causes involve different factors, ranging from the patient sphere to the health care level of services provided, and the societal preference of CS practice. Policy makers aiming to standardise cares and to reduce CSs often implement maternity pathways (MP). By investigating the MP introduced in the Sicilian region, the authors hig…
Study of forming mechanics of magnetic field–assisted single point incremental forming
2022
This paper describes the forming characteristics and mechanics of magnetic field–assisted single point incremental forming (M-SPIF) in which an Nd-Fe-B magnet ball tool is placed on top of a piece of sheet metal and is driven by an Nd-Fe-B magnet placed below the workpiece. To gain an understanding of the force mechanics that power M-SPIF, the tool motion and forming force were experimentally analyzed. In M-SPIF, the forming force is applied multi-directionally, and the resultant force direction is nearly colinear with the polarity of the permanent magnet ball tool. This suggests that the forming characteristics in M-SPIF may be controllable by controlling the magnetic polarity of the tool.
WITHDRAWN: Corrigendum to “Detection of change in persistence of a linear time series”: [J. Econom. 95 (2000) 97–116]
2001
Quantifying sunk costs and learning effects in R&D persistence
2020
Abstract This paper analyzes and quantifies the fundamental factors that are likely to cause persistence in performing R&D activities: the existence of sunk costs associated with R&D activities and the process of learning that characterizes this type of activity. We estimate our model with Spanish manufacturing firms for the period 1991-2014. By decomposing the effects of sunk costs and learning effects, we find that both are important determinants of R&D persistence, and that failing to allow for learning systematically overestimates sunk cost effects. Both large firms and SMEs benefit from direct and indirect (via productivity) effects of R&D experience, but in large firms this is more li…
The effects of using participatory working time scheduling software on sickness absence: A difference-in-differences study.
2020
Abstract Background Participatory working time scheduling is a collaborative approach to scheduling shift work. As a potential way of improving work time control, it may provide a means to reducing sickness absence in shift work. So far, experimental and quasi-experimental studies on the effects of increased work time control on sickness absence are lacking. Objective To investigate the effects of using digital participatory working time scheduling software on ward-level sickness absence among Finnish hospital employees. Participants and methods This quasi-experimental study compared the amount of sickness absence in hospital wards using a participatory working time scheduling software (n=1…
Child–display interaction:Lessons learned on touchless avatar-based large display interfaces
2020
AbstractDuring the last decade, touchless gestural interfaces have been widely studied as one of the most promising interaction paradigms in the context of pervasive displays. In particular, avatars and silhouettes have proved to be effective in making the touchless capacity of displays self-evident. In this paper, we focus on a child–display interaction approach to avatar-based touchless gestural interfaces. We believe that large displays offer an opportunity to stimulate children’s experiences and engagement; for instance, learning about art is very engaging for children but can bring a number of challenges. Our study aims to contribute to the literature on both pervasive displays and chi…
Strategies for Including Patients Recruited During Interim Analysis of Clinical Trials
2007
In clinical trials a periodical check of safety and efficacy data is often needed. For organizational reasons it is rarely desirable to stop a trial during such an interim analysis. Therefore, new study patients are included in the trial while the interim analysis is ongoing. Disregarding the additional information provided by these interim patients would be unsatisfactory, especially for an office of regulatory affairs. Consequently, the rules for group sequential or adaptive decisions must be adjusted to the recruitment of interim patients. In this paper, two strategies for modifying study designs to consider the analysis of interim patients are proposed.