Search results for "Operations Research"
showing 10 items of 1297 documents
Die Anwendung der Dynamischen Optimierung bei der Sozial-Sanitären Bezirkseinteilung
1979
Nach einer kurzen Analyse des Problems der optimalen Aufteilung eines geographischen Gebietes in sozial-sanitare Bezirke wird in der vorliegenden Arbeit fur die Losung eines solchen Problems ein Modell dynamischer Programmierung verwendet. Es werden dann zwei Algorithmen vorgeschlagen: der erste, der von der territorialen Einheit ausgeht, soll die zulassigen sozial-sanitaren Bezirke unter Berucksichtigung der Faktoren Nahe, Dichte und begrenzter Bevolke-rungsunterschied ermitteln; der zweite errechnet jene Gesamtheit der zulassigen Bezirke, die, jede territoriale Einheit nur einmal „deckend“, eine Zielfunktion auf ein Minimum reduziert, die das Gleichgewicht zwischen Angebot und Nachfrage d…
Die Methode der „direkten Koeffizientenanpassung“ (μ-Form) des Separable Programming
1970
Zur approximativen Losung von Optimierungsproblemen mit trennbaren nichtlinearen Funktionen (Separable Programming) werden haufig modifizierte Methoden der linearen Planungsrechnung verwendet. Dabei ersetzt man die nichtlinearen Funktionen durch lineare Streckenzuge. Fur diese polygonale Approximation werden in der Literatur die sog.λ-Form und die sog.δ-Form vorgeschlagen, die jedoch eine aufwendige Datenorganisation erfordern. In diesem Beitrag soll eine kompaktere Organisationsform (μ-Form) vorgeschlagen werden. Zu ihrer Durchfuhrung werden die Rechenregeln der Upper-Bounding-Technique und die Regeln zur nachtraglichen Anderung von Matrixelementen verwendet. Der Vorteil gegenuber derλ-For…
Improving the Representativeness of a Simple Random Sample: An Optimization Model and Its Application to the Continuous Sample of Working Lives
2020
This paper proposes an optimization model for selecting a larger subsample that improves the representativeness of a simple random sample previously obtained from a population larger than the population of interest. The problem formulation involves convex mixed-integer nonlinear programming (convex MINLP) and is, therefore, NP-hard. However, the solution is found by maximizing the size of the subsample taken from a stratified random sample with proportional allocation and restricting it to a p-value large enough to achieve a good fit to the population of interest using Pearson&rsquo
Basis for a general theory of organizations
2011
Purpose – The purpose of this paper is to identify the conceptual basis shared by different theories, regardless of the unit of analysis they specifically adopt. The different ontological choice (or different segment of reality studied by each theory) does not hinder conceptual common ground for a good number of organisational theories.Design/methodology/approach – The paper highlights the importance of hierarchical, social and institutional relations and of the technological, cognitive, social and institutional contents. It looks at the common conceptual contents of the two main theories examined, and those of a wide set of other theories addressed here. Both of the theories examined are i…
Regina Schlüter – an entire life devoted to tourism research
2017
Now that tourism has transformed into a growing commercial trade, which revitalizes local economies and poverty relief, social scientists were captivated by tourism as a promising theme for their i...
Stochastic dynamical modelling of spot freight rates
2014
Based on empirical analysis of the Capesize and Panamax indices, we propose different continuous-time stochastic processes to model their dynamics. The models go beyond the standard geometric Brownian motion, and incorporate observed effects like heavy-tailed returns, stochastic volatility and memory. In particular, we suggest stochastic dynamics based on exponential Levy processes with normal inverse Gaussian distributed logarithmic returns. The Barndorff-Nielsen and Shephard stochastic volatility model is shown to capture time-varying volatility in the data. Finally, continuous-time autoregressive processes provide a class of models sufficiently rich to incorporate short-term persistence …
Salinity gradient energy
2016
Abstract Beyond the most common renewable energy sources today exploited for the production of clean energy, salinity gradients power (SGP) has been attracting the increasing interest of scientists and companies involved in the field. This chapter provides an introduction to SGP, reporting a brief history of the technological developments throughout the years, from the beginning to present. A number of different SGP technologies have been developed in the last decades, all based on the concept of harvesting the energy from the controlled mixing of two solutions at different salinities. A theoretical analysis of the energy potential for SGP places this renewable source of energy among those …
Improving e-economy by regional governments
2014
Purpose – The purpose of this paper is to analyse and assess a government support programme for business innovation in a very peripherical European region: the Spanish region of Andalucía. Design/methodology/approach – Endogenous development approach is used to categorize the main public and private actions included in the government ICT support programme. Cross-time analysis has been carried out by using three territorial indicators of diffusion and effective use of ICT: the physical aspect, refereed to the infrastructures used as a base for the information society development (infrastructures, technology and equipment); the actors and their degree of organization (firms present on the in…
Delphi method applied to horticultural cooperatives
2012
PurposeAgricultural cooperatives have been able to become a strong and consolidated organizational form, although the new challenges of globalization and trade liberalization require changes in the strategic approach. The requirements of the distribution companies, consumers and government about the concentration of demand, traceability, food safety and respect for the environment had led to a thorough reorganization of agricultural food systems. So it is necessary to undertake a strategic review of horticultural cooperatives in order to conduct a strategic assessment and hence identify the strategic actions to be followed in the coming years. This paper seeks to address these issues.Design…
A method for the territorial organization of socio-sanitary services
1983
The need for a profound change in the health service has recently led to the development of a national sanitary plan, which the Italian government has submitted to the political and social forces as a midterm strategy for the transformation of the health service.