Search results for "Operation"
showing 10 items of 2969 documents
The shortest-path problem with resource constraints with -loop elimination and its application to the capacitated arc-routing problem
2014
Abstract In many branch-and-price algorithms, the column generation subproblem consists of computing feasible constrained paths. In the capacitated arc-routing problem (CARP), elementarity constraints concerning the edges to be serviced and additional constraints resulting from the branch-and-bound process together impose two types of loop-elimination constraints. To fulfill the former constraints, it is common practice to rely on a relaxation where loops are allowed. In a k-loop elimination approach all loops of length k and smaller are forbidden. Following Bode and Irnich (2012) for solving the CARP, branching on followers and non-followers is the only known approach to guarantee integer …
Coping with the costs of car dependency : A system of expedients used by low-income households on the outskirts of Dijon and Paris
2018
International audience; Living on low incomes and in a car-dependent area is often interpreted as a double burden for households, even if the two characteristics are often interdependent. While their capacity for mobility is lower, low-income households in outer suburban areas are nonetheless mobile. Their capacities in this domain should not be underestimated or overlooked. They can command a set of alternative practices or expedients to deal with car-related economic stress by a set of resources derived essentially from spatial proximity. This article aims to present and analyse the diversity of these expedients for the case of outer suburban areas around Paris and Dijon. The analysis of …
Fuzzy motion control strategy for cooperation of multiple automated vehicles with passengers comfort
2008
This paper considers motion control for a cooperative system of automated passenger vehicles. It develops a cooperative scheme based on a decentralized planning algorithm which considers the vehicles in an initial open chain configuration. In this scheme the trajectories are intersections-free, and each trajectory is planned independently of the others. To ensure the stabilization of each vehicle in the planned trajectory, a fuzzy closed loop motion control is presented, where, based on the properties of the Fuzzy maps, the Lyapunov’s stability of the motion errors is demonstrated for all the vehicles. Based on the ISO 2631-1 standard, the saturation property of the Fuzzy maps guarantees lo…
An explanation of the MRP formula in Operations Management Lesson 8
2023
El document forma part dels materials docents programats mitjançant l'ajut del Servei de Política Lingüística de la Universitat de València An explanation on how the MRP formula works Operations Management Lesson 8
The role of Interleukin-2 during the activation of cytotoxic T-lymphocytes
1983
Der vorliegende Artikel stellt eine Ubersicht dar Uber die derzeitigen Vorstellungen des Zusammenwirkens zellularer und humoraler Faktoren, die zu T-Zell-vermittelten zytotoxischen Immunreaktionen fuhren. Da im Ablauf derartiger Immunreaktionen hormonahnliche Wachstumsfaktoren (interleukine) eine entscheidende Rolle spielen, liegt der Schwerpunkt der Diskussion auf der Beschreibung dieser Mediatoren; insbesondere wird die Bedeutung von Interleukin-2 (Il-2) diskutiert. Il-2 ist ein losliches, nicht antigenspezifisches Glykoprotein mit einem Molekulargewicht von 15 000 Dalton (humanes Il-2) bzw. 30 000 Dalton (murines Il-2). Es wird in vitro von T-Helfer-Lymphozyten sezerniert, die in der Mau…
Networking strategy for competitive advantage
2011
This paper explores the potential of networking strategy as a source of competitive advantage by integrating market- based and resource-based logics. It contributes to operations management literature by considering not just supply chain structures but also others kinds of network that can emerge from horizontal agreements (i.e. alliances, partnerships, joint ventures, etc.). The paper reviews the literature and develops propositions regarding how make/buy/make together decisions, governance mechanisms and network-base structures allow firms both to pursue operations performance objectives and obtain/create valuable resources. A case study supports the propositions and shows a practical app…
Coevolution of parental investment and sexually selected traits drives sex-role divergence
2016
Sex-role evolution theory attempts to explain the origin and direction of male–female differences. A fundamental question is why anisogamy, the difference in gamete size that defines the sexes, has repeatedly led to large differences in subsequent parental care. Here we construct models to confirm predictions that individuals benefit less from caring when they face stronger sexual selection and/or lower certainty of parentage. However, we overturn the widely cited claim that a negative feedback between the operational sex ratio and the opportunity cost of care selects for egalitarian sex roles. We further argue that our model does not predict any effect of the adult sex ratio (ASR) that is …
Physical activity of children: a global matrix of grades comparing 15 countries.
2014
The Active Healthy Kids Canada (AHKC) Report Card on Physical Activity for Children and Youth has been effective in powering the movement to get kids moving by influencing priorities, policies, and practice in Canada. The AHKC Report Card process was replicated in 14 additional countries from 5 continents using 9 common indicators (Overall Physical Activity, Organized Sport Participation, Active Play, Active Transportation, Sedentary Behavior, Family and Peers, School, Community and Built Environment, and Government Strategies and Investments), a harmonized process and a standardized grading framework. The 15 Report Cards were presented at the Global Summit on the Physical Activity of Child…
Perceived Stress and Mild Cognitive Impairment among 32,715 Community-Dwelling Older Adults across Six Low- and Middle-Income Countries
2018
<b><i>Background:</i></b> Perceived stress may be a modifiable risk factor for mild cognitive impairment (MCI) and ultimately dementia, but studies on this topic from low- and middle-income countries (LMICs) are lacking. <b><i>Objective:</i></b> We assessed the association between perceived stress and MCI in six LMICs (China, Ghana, India, Mexico, Russia, and South Africa) using nationally representative data. <b><i>Methods:</i></b> Cross-sectional, community-based data on individuals aged ≥50 years from the World Health Organization’s Study on Global Ageing and Adult Health were analyzed. The definition of MCI was base…
Clinical profile and predictors of in-hospital mortality among older patients hospitalised for COVID-19.
2020
Abstract Background the coronavirus disease 2019 (COVID-19) is characterized by poor outcomes and mortality, particularly in older patients. Methods post hoc analysis of the international, multicentre, ‘real-world’ HOPE COVID-19 registry. All patients aged ≥65 years hospitalised for COVID-19 were selected. Epidemiological, clinical, analytical and outcome data were obtained. A comparative study between two age subgroups, 65–74 and ≥75 years, was performed. The primary endpoint was all cause in-hospital mortality. Results about, 1,520 patients aged ≥65 years (60.3% male, median age of 76 [IQR 71–83] years) were included. Comorbidities such as hypertension (69.2%), dyslipidaemia (48.6%), card…