An implicit model for multi-activity shift scheduling problems

Purpose – this paper aims to develop a non-stationary hypercube model capable of uniting the properties that models for both problems seek (location and shift-scheduling problems). Theoretical framework – We present the proposed model using a mixed discrete-continuous time Markov chain and compares it to a discrete-event simulation through an illustrative example. Design/methodology/approach – The method used in this paper is quantitative with a comparison between an approach of simulation and an exact model. Findings – The results show a high similarity between both models. However, the proposed model does not present noise in performance measures such as waiting times and travel times. Nevertheless, the study of their residuals revealed that the proposed model has a lower sensitivity to events, such as shift endings and imperfections in dispatch preferences. Further studies may reduce such a variation by improvements in the calculations of performance measurements. Research, Practical & Social implications – The mentioned results suggest that the proposed model may become an option for applications uniting location and shift-scheduling problems. Originality/value – When developing location problems, we seek models that are capable of representing the pertinent geographic characteristics to the problem. On the other hand, when developing shift-scheduling problems, we seek models capable of capturing transient fluctuations in the components (such as demand, service times, available workforce, among others) of such a system. Therefore, in the search to improve the daily operations of systems, such as emergency service systems (ambulances, police, firefighters) using either of the two problems individually, it may lead to flawed conclusions. Keywords - Emergency Service Systems; Queueing Theory; Hypercube non-stationary; Discrete Event Simulation; Performance Measurement.

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Formal languages for integer programming modeling of shift scheduling problems

Constraints ◽

10.1007/s10601-009-9083-2 ◽

2009 ◽

Vol 16 (1) ◽

pp. 54-76 ◽

Cited By ~ 29

Author(s):

Marie-Claude Côté ◽

Bernard Gendron ◽

Claude-Guy Quimper ◽

Louis-Martin Rousseau

Keyword(s):

Integer Programming ◽

Formal Languages ◽

Scheduling Problems ◽

Shift Scheduling

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Solution approaches to large shift scheduling problems

RAIRO - Operations Research ◽

10.1051/ro:2008006 ◽

2008 ◽

Vol 42 (2) ◽

pp. 229-258 ◽

Cited By ~ 8

Author(s):

Monia Rekik ◽

Jean-François Cordeau ◽

François Soumis

Keyword(s):

Scheduling Problems ◽

Shift Scheduling ◽

Large Shift

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Two-Operation Crane Scheduling Problems

IIE Transactions ◽

10.1080/05695558208974598 ◽

1982 ◽

Vol 14 (3) ◽

pp. 147-155 ◽

Cited By ~ 6

Author(s):

R. W. Lieberman ◽

I. B. Turksen

Keyword(s):

Scheduling Problems ◽

Crane Scheduling

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Russian Citizens' Representations of the Country's Position in the Geopolitical Space of the Commonwealth of Independent States, Europe, and the World

European Psychologist ◽

10.1027//1016-9040.8.4.238 ◽

2003 ◽

Vol 8 (4) ◽

pp. 238-251

Author(s):

Victor F. Petrenko ◽

Olga V. Mitina ◽

Kirill A. Bertnikov

Keyword(s):

Well Being ◽

Multidimensional Space ◽

Commonwealth Of Independent States ◽

Repertory Grids ◽

Implicit Model ◽

The World ◽

Public Consciousness ◽

Independent States ◽

Invariant Factors

The aim of this research was the reconstruction of the system of categories through which Russians perceive the countries of the Commonwealth of Independent States (CIS), Europe, and the world as a whole; to study the implicit model of the geopolitical space; to analyze the stereotypes in the perception of different countries and the superposition of mental geopolitical representations onto the geographic map. The techniques of psychosemantics by Petrenko, originating in the semantic differential of Osgood and Kelly's “repertory grids,” were used as working tools. Multidimensional semantic spaces act as operational models of the structures of consciousness, and the positions of countries in multidimensional space reflect the geopolitical stereotypes of respondents about these countries. Because of the transformation of geopolitical reality representations in mass consciousness, the commonly used classification of countries as socialist, capitalist, and developing is being replaced by other structures. Four invariant factors of the countries' descriptions were identified. They are connected with Economic and Political Well-being, Military Might, Friendliness toward Russia, and Spirituality and the Level of Culture. It seems that the structure has not been explained in adequate detail and is not clearly realized by the individuals. There is an interrelationship between the democratic political structure of a country and its prosperity in the political mentality of Russian respondents. Russian public consciousness painfully strives for a new geopolitical identity and place in the commonwealth of states. It also signifies the country's interest and orientation toward the East in the search for geopolitical partners. The construct system of geopolitical perception also depends on the region of perception.

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