Search results for "Operations"

Tourism-km: A variant of MMKP applied to the tourism domain

2012

International audience; We are interested in an original real-world problem coming from tourism field. We describe a modelling of the problem and propose a first approach that mixes knowledge management and operational research methods. Our algorithms have been implemented in order to produce tourism solutions that are not unique for a given request but that take into account the preferences of the tourist user and provide a personalized solution. We report computational results obtained on real-world instances.

Theoretical Aspects of Scheduling Coupled-Tasks in the Presence of Compatibility Graph

2012

International audience; This paper presents a generalization of the coupled-task sche-duling problem introduced by Shapiro \cite{Shapiro}, where considered tasks are subject to incompatibility constraints depicted by an undirected graph. The motivation of this problem comes from data acquisition and processing in a mono-processor torpedo used for underwater exploration. As we add the compatibility graph, we focus on complexity of the problem, and more precisely on the boundary between $\mathcal{P}$ and $\mathcal{NP}$-completeness when some other input parameters are restricted (e.g. the ratio between the durations of the two sub-tasks composing a task): we adapt the global visualization of …

Stratified Autocalibration of Cameras with Euclidean Image Plane

2020

International audience; This paper tackles the problem of stratified autocalibration of a moving camera with Euclidean image plane (i.e. zero skew and unit aspect ratio) and constant intrinsic parameters. We show that with these assumptions, in addition to the polynomial derived from the so-called modulus constraint, each image pair provides a new quartic polynomial in the unknown plane at infinity. For three or more images, the plane at infinity estimation is stated as a constrained polynomial optimization problem that can efficiently be solved using Lasserre's hierarchy of semidefinite relaxations. The calibration parameters and thus a metric reconstruction are subsequently obtained by so…

Prise de décision dynamique dans la sélection des maintenances des tournées de techniciens

2022

In Situ, Airborne Instrumentation: Addressing and Solving Measurement Problems in Ice Clouds

2012

The workshop on in situ airborne instrumentation: addressing and solving measurement problems in ice clouds, June 25-27, 2010, Oregon, aimed to identify unresolved questions concerning ice formation and evolution in ice clouds, assess the current state of instrumentation that can address these problems, introduce emerging technology that may overcome current measurement issues, and recommend future courses of action to improve our understanding of ice cloud microphysical. Eleven presentations were made covering measurement challenges associated measuring the composition and concentration of all the modes of ice nuclei (IN), measuring the morphology, mass, surface, and optical properties of …

Rational expectations behaviour of households : indicators, measures and tests

1996

The analysis of household survey data regularly conducted by INSEE from 1973 to 1994 allows to detect behaviors about anticipation and perception purpose concerning price and employment. The nature of available information offers the opportunity first to develop a rational expectation test for qualitative data, then to point out expectation errors associated to optimistic and/or pessimistic attitudes for the evolution of these two economic variables. The paper provides a series of synthetic and desegregated indicators (developed usually by psychologists, sociologists, economists, ...) then rational expectation tests and correct anticipation tests. Empirical results permit to establish rathe…

Test methodologies for the unitary root

1998

This paper provides a critical survey on unit root testing procedures frequently used in empirical literature. The importance of the hypothesis of linearity of the deterministic component is stressed because its misspecification may result in the false conclusion that the time series has a unit root. Testing strategies elaborated by Dickey, Bell and Miller (1986), Perron (1988) and Dolado, Jenkinson and Sosvilla-Rivero (1990) are compared and their limit is evaluated. An empirical testing strategy is then proposed and applied to the analysis of the nonstationarity exhibited by real GDP in France. We show that it is possible to find some flexible specifications that enable us to reject the u…

Developing a framework for designing humanitarian blockchain projects

2021

International audience; Blockchain technology promises to improve the efficiency, transparency, and accountability of humanitarian operations. Yet at the same time, especially the humanitarian context with its characteristic volatility poses unique challenges to any technology. Most prominent are the humanitarian principles that are fundamental to humanitarian operations. These ethical principles are set to protect the most vulnerable populations. Designing blockchain projects in the humanitarian context therefore requires a systematic framework that helps humanitarians make critical choices.While some design instructions can be found for commercial applications, the humanitarian context re…

Construction of quality indicators based on pre-established goals: application to a colombian public university

2020

This study creates indicators of adequacy and excellence based on multiple-criteria decision-making (MCDM) methods and fuzzy logic. The calculation of indicators presents two main difficulties: The nature of the data (numerical, interval, and linguistic values are mixed) and the objective of each criterion (which does not have to reach either the maximum or the minimum). A method is proposed, based on similarity measures with predetermined ideals, that is capable of overcoming these difficulties to provide easy-to-interpret information about the quality of the alternatives. To illustrate the usefulness of this proposed method, it has been applied to data collected from students across nine …

Browsing the information highway while driving: three in-vehicle touch screen scrolling methods and driver distraction

2012

Distraction effects of three alternative touch screen scrolling methods for searching music tracks on a mobile device were studied in a driving simulation experiment with 24 participants. Page-bypage scrolling methods with Buttons or Swipe that better facilitate resumption of visual search following interruptions were expected to lead to more consistent in-vehicle glance durations and thus, on less severe distraction effects than Kinetic scrolling. As predicted, Kinetic scrolling induced decreased visual sampling efficiency and increased visual load compared to Swipe, increased experienced workload compared to both Buttons and Swipe, as well as decreased lane keeping accuracy compared to ba…