Search results for "Operations"
showing 10 items of 1692 documents
Assessing statistical significance in multivariable genome wide association analysis
2016
Motivation: Although Genome Wide Association Studies (GWAS) genotype a very large number of single nucleotide polymorphisms (SNPs), the data are often analyzed one SNP at a time. The low predictive power of single SNPs, coupled with the high significance threshold needed to correct for multiple testing, greatly decreases the power of GWAS. Results: We propose a procedure in which all the SNPs are analyzed in a multiple generalized linear model, and we show its use for extremely high-dimensional datasets. Our method yields P-values for assessing significance of single SNPs or groups of SNPs while controlling for all other SNPs and the family wise error rate (FWER). Thus, our method tests whe…
The adaptive value of tandem communication in ants:Insights from an agent-based model
2021
AbstractSocial animals often share information about the location of resources, such as a food source or a new nest-site. One well-studied communication strategy in ants is tandem running, whereby a leader guides a recruit to a resource. Tandem running is considered an example of animal teaching because a leader adjusts her behaviour and invests time to help another ant to learn the location of a resource more efficiently. Tandem running also has costs, such as waiting inside the nest for a leader and a reduced walking speed. Whether and when these costs outweigh the benefits of tandem running is not well understood. We developed an agent-based simulation model to investigate the conditions…
A webGIS-based system for real time shelf life prediction
2016
Technologies to acquire and monitor changes in the product shelf life were described.Four different SL predictive models were considered.A simulated transport using a prototype of Smart Logistic Unit was analysed.Real time shelf life prediction system was implemented in a webGIS platform. Shelf-life (SL) prediction and Least Shelf-life First Out (LSFO) stock strategy are important factors in perishable food supply chain in order to reduce quality and economic losses.In particular, distribution represents one of the main critical phases in logistic chain management and only the introduction of monitoring procedure can allow a reduction in food losses. Literature shows several mathematical mo…
Changes in the international wine market competitiveness
2017
This study offers a contribution to understanding the complexity of the international wine trade analysing the specialisation patterns of 14 among the most important wine world actors in the period 2007â2016, in order to verify if the patterns of comparative advantages for the trade of this countries have experienced significant changes. Using the Lafay index, as a comparative advantage measure, our results reveal deep changes in the global wine market exchange. Our result constitutes a base element for the future development of the competitive scenario and provides some both theoretical and practical implications. In the baseline projection, the maintenance of the competitive position is…
Curve Extraction by Geodesics Fusion: Application to Polymer Reptation Analysis
2016
© Springer International Publishing Switzerland 2016. In the molecular field, researchers analyze dynamics of polymers by microscopy: several measurements such as length and curvature are performed in their studies. To achieve correct analysis they need to extract the curve representing as good as possible the observed polymer shape which is a grayscale thick curve with noise and blur. We propose, in this paper, a method to extract such a curve. A polymer chain moves in a snake-like fashion (Reptation): it can self-intersect and form several complex geometries. To efficiently extract the different geometries, we generate the curve by computing a piecewise centerline browsing the shape by ge…
Evaluating a hierarchical approach to landscape-level harvest scheduling
2018
Forest planning at the landscape level has the potential to become a large intractable problem. In Finland, Metsähallitus (the state enterprise that manages federally owned land) creates strategic plans to determine the appropriate harvest level. While these plans are feasible, they are not implementable in practice as the harvests are scattered temporally and spatially. Requiring that harvests be organized both temporally and spatially for practical implementation can result in an intractable problem. Through a hierarchical approach, the problem can be organized into steps in which the intractable problem is broken down into smaller easily solvable parts. As an approximation technique, th…
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, …
Fuzzy Portfolio Selection Models for Dealing with Investor’s Preferences
2017
This chapter provides an overview of the authors’ previous work about dealing with investor’s preferences in the portfolio selection problem. We propose a fuzzy model for dealing with the vagueness of investor preferences on the expected return and the assumed risk, and then we consider several modifications to include additional constraints and goals.
The Impact of Lbos on Investment Policies and Operations of Acquired French Firms
2002
This paper evaluates the extent that French LBO targets’ investment policy and operations can account for their overperformance discrepancy. Our empirical study has been carried out on 132 French LBOs between 1989 and 1994. The results show that the abnormal plunge in economic return cannot be explained by overinvestments or by inefficient working capital management. Nevertheless, abnormal increases in wages, supplies and/or sales price reductions appear to be prominent.
Early warning of systemic risk in global banking: eigen-pair R number for financial contagion and market price-based methods
2021
AbstractWe analyse systemic risk in the core global banking system using a new network-based spectral eigen-pair method, which treats network failure as a dynamical system stability problem. This is compared with market price-based Systemic Risk Indexes (SRIs), viz. Marginal Expected Shortfall (MES), Delta Conditional Value-at-Risk (Delta-CoVaR), and Conditional Capital Shortfall Measure of Systemic Risk (SRISK) in a cross-border setting. Unlike paradoxical market price based risk measures, which underestimate risk during periods of asset price booms, the eigen-pair method based on bilateral balance sheet data gives early-warning of instability in terms of the tipping point that is analogou…