Search results for "Operations Research"
showing 10 items of 1297 documents
Simulation-based Evacuation Planning for Urban Areas
2021
Evacuation planning is a critical task in disaster management. Especially in situations such as natural disasters or terrorist attacks, large crowds need to move away from danger and reach designated safe zones. For this purpose, various approaches that efficiently compute evacuation plans in urban areas have been proposed. To evaluate the computed plans, previous works employ heuristics that can only roughly estimate the egress time of each plan. Intuitively, a much better approach is to estimate the egress time via simulation. However, designing a simulation model is usually a time-consuming task and, what is more, this model can only be used to evaluate evacuation plans for a specific ar…
A bibliometric review of cryptocurrencies as a financial asset
2021
Within a decade, cryptocurrencies have captured significant attention. After Bitcoin's emergence in 2008, new cryptocurrencies started to enter the financial market. We use bibliometric analysis to...
Complexity traits and synchrony of cryptocurrencies price dynamics
2021
AbstractIn this study, we characterized the dynamics and analyzed the degree of synchronization of the time series of daily closing prices and volumes in US$ of three cryptocurrencies, Bitcoin, Ethereum, and Litecoin, over the period September 1,2015–March 31, 2020. Time series were first mapped into a complex network by the horizontal visibility algorithm in order to revel the structure of their temporal characters and dynamics. Then, the synchrony of the time series was investigated to determine the possibility that the cryptocurrencies under study co-bubble simultaneously. Findings reveal similar complex structures for the three virtual currencies in terms of number and internal composit…
Giménez Moreno, Rosa (ed.). (2010). Words for Working. Professional and Academic English for International Business and Economics
2011
Gimenez Moreno, Rosa (ed.). (2010). Words for Working. Professional and Academic English for International Business and Economics. Valencia. Universitat de Valencia (PUV). Coleccion: Educacio. Laboratori de Materials 28. Pages: 400. ISBN: 978-84-370- 7873-1 There are many ways in which one can sell and it is certainly one of the most important aspects of business to be able to place a product successfully in the market. From a creative and editorial point of view a telling title is similarly weighty and this book fulfils that premise: a hand-book whose very title calls the attention of the prospective reader/user by underlining its operative quality. Words to work with, operative language, …
Modeling crowd dynamics through coarse-grained data analysis
2018
International audience; Understanding and predicting the collective behaviour of crowds is essential to improve the efficiency of pedestrian flows in urban areas and minimize the risks of accidents at mass events. We advocate for the development of crowd traffic management systems, whereby observations of crowds can be coupled to fast and reliable models to produce rapid predictions of the crowd movement and eventually help crowd managers choose between tailored optimization strategies. Here, we propose a Bi-directional Macroscopic (BM) model as the core of such a system. Its key input is the fundamental diagram for bi-directional flows, i.e. the relation between the pedestrian fluxes and d…
Interprofessional collaboration during an emergency ward’s rounds
2015
Purpose – The purpose of this paper is to explore interprofessional collaboration during ward rounds on a Finnish emergency and infection ward from the viewpoint of three central professional groups: physicians, nurses and secretaries. Design/methodology/approach – The authors utilise an ethnographically informed approach, with observations and interviews as the data collection devices. The data comprise ten interviews with staff members and ten hours of observations. The data were analysed using qualitative thematic analysis. Findings – The ward rounds were found to be rather physician- and medicine-centred, and mostly not interprofessional. Nurses and secretaries in particular expressed …
Understanding Decision Support in Large-Scale Disasters: Challenges in Humanitarian Logistics Distribution
2017
Disasters are characterized by conflicting, uncertain, or lacking data. Nevertheless, humanitarian responders need to make rapid decisions. This is particularly true for the immediate response to a sudden onset disaster. Since most humanitarian decision support systems (DSS) make important assumptions on data availability and quality that are often not fulfilled in practice, decision-makers are largely left to their experience. In this paper, we identify three major challenges for an operational DSS to support distribution planning: (i) deep uncertainty; (ii) reflecting field conditions and constraints; and (iii) rapid humanitarian logistics modeling. We review the relevant theories and pro…
Requirements for Relief Distribution Decision-Making in Humanitarian Logistics
2020
Making efficient and effective decisions in the chaotic environment of humanitarian relief distribution (HRD) is challenging. Decision-makers need to concentrate on numerous decision factors categorized into decision objectives, variables, and constraints. Recent HRD literature focuses on optimizing procedures while neglecting the quantification of essential requirements (decision factors) for information systems to provide decision-making support. In this article, we address this gap by accumulating affecting decision factors from both literature and practice. We investigated the practical implications of these factors in HRD decision-making by measuring the preferences of a Delphi panel c…
Survey of methods to visualize alternatives in multiple criteria decision making problems
2012
When solving decision problems where multiple conflicting criteria are to be considered simultaneously, decision makers must compare several different alternatives and select the most preferred one. The task of comparing multidimensional vectors is very demanding for the decision maker without any support. Different graphical visualization tools can be used to support and help the decision maker in understanding similarities and differences between the alternatives and graphical illustration is a very important part of decision support systems that are used in solving multiple criteria decision making problems. The visualization task is by no means trivial because, on the one hand, the grap…
Shaping inter-firm collaboration in new product development in the automobile industry: A trade-off between a transaction and relational-based approa…
2008
Abstract Shaping collaboration in the new product development (NPD) has always been a very difficult task, especially in complex industries like the automobile one. This complexity is particularly true during the engineering phase of the NPD process, where different complex systems are to be designed in a collaborative way. Basically, two-kind of approaches have been observed in the literature and industry: one is more related to market transactions, specifically the west car-company style, the other is more relational based, as in the Japanese car-company style. Now, the increasing globalisation of the industry asks for a merge of the two approaches; indeed, the increasing use of standard …