Wietse Dol - Academia.edu (original) (raw)

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Papers by Wietse Dol

RePEc: Research Papers in Economics, Feb 1, 2005

ICES Journal of Marine Science, 2000

This paper presents the MicroWave approach that has been developed to improve the process of mode... more This paper presents the MicroWave approach that has been developed to improve the process of modeling in the context of micro simulation. It leads to a more efficient model development, better quality of models and their output and improvement in knowledge management. A conceptual framework has been developed and translated into a hierarchical structure of GAMS program code. Besides, several software applications and other tools have been developed for support. These products are presented and some examples illustrate how MicroWave can be applied. MicroWave is especially useful in interdisciplinary research in which different persons are involved in the modeling process and when different models have to be combined.

In this paper we will show how 4 T E X can be used to incorporate graphics in T E X documents.

Nowadays, there is no lack of data on trade issues. There are many ways to get data, e.g. CD-rom ... more Nowadays, there is no lack of data on trade issues. There are many ways to get data, e.g. CD-rom and internet. This also presents us with a problem. What do we really need? How reliable is the data and is there even more/better data available? How to analyze and present this data? How, do these different data sources all work? Etc. The TSA-express system has been developed at LEI to meet the demand for easily accessible trade data from various sources. Besides this uniform access TSA-express allows the user to extend the database with custom-made selections of various variables (e.g. we added the GTAP product classification to COMEXT and PCTAS). TSA-express combines speed with versatility, and offers the user many different ways to analyze and present the data. TSA-express is used regularly at LEI and hence we check and update the metadata we get. We add product and country groups because our users need them. Last year we presented in a poster session the first version of TSA-expres...

The superpopulation approach is often used to estimate certain populat ion parameters more accura... more The superpopulation approach is often used to estimate certain populat ion parameters more accurately than is possible by applying the classical sampling theory. By postulating a superpopulation model it is for instance possible to make inferences about subpopulations (also called small areas) using the whole sample instead of only the sampled elements that are in the subpopulation. If such a superpopulat ion model applies, more accurate results can be obtained then by classical sampling theory. This is especially the case if we are dealing with a small subpopulation and a sample that contains only a very small number of individuals from this subpopulation. The accuracy of the superpopulation approach, however, depends on the validity of the model used. This paper considers bilinear estimators, i.e. estimators that are linear with regard to both the model and the sampling design. The mean-squared error is used as a yardstick. In the class of bilinear estimators, optimal estimators a...

The last three years RIVO-DLO and LEI-DLO have developed a bio-economic simulation model for the ... more The last three years RIVO-DLO and LEI-DLO have developed a bio-economic simulation model for the Dutch beam trawl fishery. At the VII th IIFET conference in Taipei (1994, Taiwan) some preliminary results were presented and at the 4 EAFE bio-economic modeling workshop in Edinburgh (1995, United Kingdom) the final model was demonstrated. Until then, no real life simulations were done. Recently RIVO-DLO and LEI-DLO used the FLATFISH model to simulate and evaluate several (European Union and National) management decisions. In this paper, the bio-economic model is described and some simulation results are presented. This paper shows that the FLATFISH model is not only a toy but that it can be a powerful management tool.

The development of farm models used for policy evaluation is often characterized by poor transfer... more The development of farm models used for policy evaluation is often characterized by poor transferability and reusability, lack of quality assessment and poor usage comfort. The goal of the MicroWave project is to tackle these problems with a set of software tools and procedures which are described in this paper. A conceptual framework was designed and translated into a GAMS-implemented version of a generic framework for model building. Several software applications were developed to support model building, model-using and documentation. In addition, a financial-economic simulation model is described as a case to demonstrate the MicroWave approach and its success in resolving the distinguished problems.

In this paper we will show how 4TEX can be used to incorporate graphics in TEX documents. Using 4... more In this paper we will show how 4TEX can be used to incorporate graphics in TEX documents. Using 4TEX it not only becomes easy to include graphics in TEX files, but also makes it possible to preview and print TEX documents (including graphics) on any machine and any printer. For inserting graphics in TEX documents, 4TEX uses the style filefigures.sty, the shareware programs TEXCAD and GRAPHIC WORKSHOP, and the freeware programs: HP2XX, BM2FONT ,P CL TOMSP, and GHOSTSCRIPT. All these programs are discussed and we also discuss how 4TEX uses the strength of these programs to incorporate graphics in TEX documents.