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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

A new method of data quality control in production data using the capacitance-resistance model

Cao, Fei, active 21st century 02 November 2011 (has links)
Production data are the most abundant data in the field. However, they can often be of poor quality because of undocumented operational problems, or changes in operating conditions, or even recording mistakes (Nobakht et al. 2009). If this poor quality or inconsistency is not recognized as such, it can be misinterpreted as a reservoir issue other than the data quality problem that it is. Thus quality control of production data is a crucial and necessary step that must precede any further interpretation using the production data. To restore production data, we propose to use the capacitance resistance model (CRM) to realize data reconciliation. CRM is a simple reservoir simulation model that characterizes the connectivity between injectors and producers using only production and injection rate data. Because the CRM model is based on the continuity equation, it can be used to analyze the production corresponding to the injection signal in the reservoir. The problematic production data are then put into the CRM model directly and the resulting CRM output parameters are used to evaluate what the correct production response would be under current injection scheme. We also make sensitivity analysis based on synthetic fields, which are heterogeneous ideal reservoir models with imposed geology and well features in Eclipse. The aim is to show how bad data could be misleading and the best way to restore the production data. Using the CRM model itself to control data quality is a novel method to obtain clean production data. We can then apply the new clean production data in reservoir simulators or any other processes where production data quality matters. This data quality control process can help better understand the reservoir, analyze its behavior in a more ensured way and make more reliable decisions. / text
32

Agregatinių imitacinių modelių programinio kodo generavimas ir integravimas su duomenų baze / Source code generation for aggregate simulation models and their integration with database

Munčys, Darius 16 August 2007 (has links)
Šiame darbe analizuojama MDE programų inžinerijos metodai, o taip pat OMG MDA ir Microsoft DSL Tools. MS DSL Tools - tai galingas priedas prie MS Visual Studio 2005, skirtas taikymo srities kalbų metamodelių kūrimui ir grafinių aplinkų darbui su jomis generavimui. Taip pat galima sukurti tekstinų šabloną, kuris gali transformuoti duotą modelį į programinį kodą. Darbe aprašomas sukurtas modeliavimo kalbos metamodelis. taip pat aprašoma tekstinių šablonų kalba, skirta modelių trasformacijom kurti. / This paper analyses MDE approach to software engineering as well as OMG’s MDA and Microsoft DSL Tools. MS DSL Tools are a powerful addition to MS Visual Studio 2005 for creating your own Domain Specific Language metamodels and generating IDEs for working with it. Then you can make a text template to transform your model directly into code. The work describes developed aggregate modeling language metamodel. It also explains text template language for model transformations. The research also includes analysis of the possibility to use model transformations to generate code for data acquisition form database.
33

A macroeconometric model for Algeria : a medium term macroeconometric model for Algeria 1963-1984, a policy simulation approach to Algerian development problems

Laabas, Belkacem January 1989 (has links)
This thesis is concerned with the development and use of a macroeconometric model for the Algerian economy between 1963 and 1984. The model was built because of a systematic lack of applied econometric studies pertaining to Algeria at both the macroeconomic and microeconomic level. It is hoped that the model will fill a gap in this area and will contribute to the much neglected field of applied econometric research with regard to Algeria. This lack of applied econometric studies for Algeria meant that the modelling exercise described here has had to rely on an extensive specification search based on evidence relating to Algeria's economic structure and policy, economic theory, and the experience of Less Developed Countries in the area of macroeconomic model-building. The lack of data was a major constraint in this area and part of this study consisted of collecting and compiling a large database. After the country's independence in 1962, Algerian macroeconomic policy aimed to create a strong industrial system and to satisfy the population's basic needs. It relied on heavy industrialisation to modernise the economy, oil revenues to finance development, and central planning as the major tool of macroeconomic regulation. The accumulation rate was high and the growth record was generally good. However high unemployment and inflation, considerable disequilibrium, low productivity, a vulnerable balance of payments and unsustainable external debt are the major macroeconomic problems that policy-makers have had to face. The model's equations were first estimated using the OLS method and were subjected to stringent statistical tests. The degree of test significance and parameter correspondence to a priori views on the economy was good. when the model was constructed, it was estimated using a 2SLS principal component method. The OLD results were found to be reasonably feasible. The equations were collected into a system of 63 equations and solved using dynamic simulation technique. The model was solved successfully and its tracking of historical data was reasonably good. Further tests were carried out to study its dynamic features. Having constructed the model, it was then used extensively to perform simulation analysis. The experiments ranged from those concerning the goverment's current expenditure to its monetary policy. In all, nine simulation exercises were carried out. These were revealing on the workings of the Algerian economy. The model was further used in scenario analysis. First the model was used to develop an ex ante forecast employing a linear trend model for the exogenous variables. The forecast database was used to generate multipliers. The policy analysis was constructed to coincide with the implementation of the Second Five Year Plan (1985-1989). The feasibility of the plan was examined by varying the price of oil according to three hypotheses. The aim of this test was to develop a realistic framework for applied macroeconomic analysis.
34

Estimation of forest variables using airborne laser scanning /

Holmgren, Johan, January 2003 (has links) (PDF)
Diss. (sammanfattning). Umeå : Sveriges lantbruksuniv., 2003. / Härtill 5 uppsatser.
35

A model of pH and redox buffer depletion in waste landfills /

Crawford, James, January 1900 (has links) (PDF)
Diss. (sammanfattning) Stockholm : Tekn. högsk. / Härtill 4 uppsatser.
36

Evaporation, soil moisture and soil temperature of bare and cropped soils /

Alvenäs, Gunnel, January 1900 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.
37

Assessment of field machinery performance in variable weather conditions using discrete event simulation /

de Toro A., Alfredo, January 2004 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 4 uppsatser.
38

Management and regulated harvest of moose (Alces alces) in Sweden /

Sylvén, Susanne, January 2003 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 4 uppsatser.
39

Computational statistics with environmental and remote sensing applications /

Teterukovskiy, Alexei, January 2003 (has links) (PDF)
Diss. (sammanfattning) Umeå : Sveriges lantbruksuniv., 2003. / Härtill 5 uppsatser.
40

An improved dual-permeability model of solute transport in structured soils : model development and parameter identification in laboratory and field experiments /

Larsbo, Mats, January 2005 (has links) (PDF)
Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv. / Härtill 3 uppsatser.

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