Search results for "Operations"
showing 10 items of 1692 documents
Nurse Scheduling Problem: An Integer Programming Model with a Practical Application
2012
We use a binary integer programming model to formulate and solve a nurse scheduling problem (NSP) which maximally satisfies nurse preferences. In a practical application of a VA hospital, besides considering the scheduling of two types of nurses (registered nurses and licensed practical nurses), two other types of employees (nursing assistants and health care techs), one nurse manager, and a clinical nurse leader are also included in our model. Most of these employees are working full-time. In addition, we distinguish the schedule of weekdays and weekends with different requirements and different preferences for employees. Besides the requirements for each shift, we consider requirements fo…
Variable Neighborhood Search for the Vertex Separation Problem
2012
The vertex separation problem belongs to a family of optimization problems in which the objective is to nd the best separator of vertices or edges in a generic graph. This optimization problem is strongly related to other well-known graph problems; such as the Path-Width, the Node Search Number or the Interval Thickness, among others. All of these optimization problems are NP-hard and have practical applications in VLSI, computer language compiler design or graph drawing. Up to know, they have been generally tackled with exact approaches, presenting polynomial-time algorithms to obtain the optimal solution for speci c types of graphs. However, in spite of their practical applications, these…
From the crowd to the market: The role of reward-based crowdfunding performance in attracting professional investors
2017
Abstract We focus on new technology-based entrepreneurial ventures engaging in reward-based crowdfunding and examine the effect of their performance in such funding channel on the likelihood of securing subsequent funding from professional investors. We also study how this effect is influenced by the presence of patents granted for the new product idea and the entrepreneur social capital. Results from a sample of technology projects launched on Kickstarter demonstrate that pledging a higher amount of money in crowdfunding can ignite professional investors’ interest and thus help secure subsequent funding. However, this positive evidence is effective only when complemented by the presence of…
Multiple Objective Analysis of Input-Output Models for Emergency Management
1990
This paper shows how a visual, interactive, dynamic multiple objective linear programming decision support system can effectively be used for analyzing input-output models. We have applied our approach to studying the quantitative effects of economic or political crises to the Finnish economy. Examples of such crises are nuclear power plant accidents, trade embargoes, and international conflicts. An input-output model of the Finnish economy with 17 industries (sectors) is employed. Our system has been implemented on a microcomputer and is being used by the National Board of Economic Defense. Several typical case situations are discussed.
"A Comment on Tobias Kronenberg's "Construction of Regional Input-Output Tables Using Nonsurvey Methods: The Role of Cross-Hauling"
2012
This article examines the effectiveness of a new non-survey regionalization method: Kronenberg’s Cross-Hauling Adjusted Regionalization Method (CHARM). This aims to take into account the fact that regions typically both import and export most commodities. Data for Uusimaa, Finland’s largest region, are employed to carry out a detailed empirical test of CHARM. This test gives very encouraging results. CHARM is suitable for studying environmental questions, but it can only be applied in situations where foreign imports have been included in the national input–output table. Where the focus is on regional output and employment, location quotients (LQs) can be used for purposes of regionalizati…
An analysis of the scientific productivity and visibility of publications on usability (1971-2005)
2009
Aims: To analyse usability-related articles published in the period 1971-2005 from a bibliometric point of view. Methods: A search for articles was made in the CSIC databases, the Social Science Citation Index, Science Citation Index, PsycInfo, MEDLINE and Inspec databases, using ad hoc search strategies designed for each. Contribution, specific contribution and overlap indices were calculated, as were the indicators of change in scientific production, the productivity of institutions and journals, and the distribution of journals by area of knowledge. Results: An exponential increase in the number of published articles was recorded, with the highest increase seen over the last five years. …
Uncertainty Assessment of a Water-Quality Model for Ephemeral Rivers Using GLUE Analysis
2011
Every model is, by definition, a simplification of the system under investigation. Although it would be desirable to reduce the gap between the simulated and the observed behaviors of the system to zero, this reduction is generally impossible owing to the unavoidable uncertainties inherent in any modeling procedure. Uncertainty analyses can provide useful insights into the best model approach to be used for obtaining results with a high level of significance and reliability. The evaluation of parameter uncertainties is necessary for calibration and for estimating the impact of these uncertainties on model performance. In this context, the uncertainty of a river water-quality model developed…
Assessment of data availability influence on integrated urban drainage modelling uncertainty
2009
In urban water quality management, several models are connected and integrated for analysing the fate of pollutants from the sources in the urban catchment to the final recipient; classical problems connected with the selection and calibration of parameters are amplified by the complexity of the modelling approach increasing their uncertainty. The present paper aims at studying the influence of reductions in available data on the modelling response uncertainty with respect to the different integrated modelling outputs (both considering quantity and quality variables). At this scope, a parsimonious integrated home-made model has been used allowing for analysing the combinative effect of data…
Control points deployment in an Intelligent Transportation System for monitoring inter-urban network roadway
2022
Abstract The constant evolution of transportation systems and traffic in developing countries is nowadays confronted with a problem of road safety and therefore of a high accident rate, especially in the context of inter-urban road transport. In this work, we propose a communication architecture for an Intelligent Transport System (ITS) to provide surveillance in an inter-urban transport network in the context of developing countries. We introduce two types of control points: Relay Control Points (RCP) and Treatment Control Points (TrCP). We also designed two multi-objective models for the deployment of these points. In order to ensure good coverage, to minimize the cost of installation and…
The CFO’s Information Challenge in Managing Macroeconomic Risk
2010
In this paper we examine the role of the CFO in setting risk management strategy with respect to macroeconomic risk, in particular, and we consider the information requirements for setting a strategy that is consistent with corporate objectives. We argue that macroeconomic risk management requires a broad approach encompassing financial, operational and strategic considerations. Furthermore, several interdependent sources of risk in the macroeconomic environment must be taken into account. Once this interdependence among, for example, exchange rates, interest rates and inflation are taken into account macroeconomic risk management can be considered a relatively self-contained aspect of Inte…