Krzysztof Skabek

Rough Sets in Economic Applications

Making economic decisions is indeed a very interesting and perspective domain for many applications of methods and tools of computer science. However, economic decision problems are difficult to formalize. First of all it results from their complex character and great number of parameters describing their evolution, inexplicitness and incompleteness of available information as well as shortage of explicit criteria explaining economic decisions. Thus in economic decisions we often use intuition and knowledge which is accumulated in the process of creative generalization of practical experiments and observation results or empirical analysis. The same should be obviously considered during development of computer systems which support the process of making economic decisions.

Implementation of Progressive Meshes for Hierarchical Representation of Cultural Artifacts

In the article we focused on progressive meshes which are the way to hierarchically represent 3D objects. We present the Me3d system developed to process and present digitalized objects of cultural heritage. The optimization of progressive meshes was described and the rendering performance of displaying the simplified meshes is analyzed.

From Museum Exhibits to 3D Models

The article presents the use of 3D scanners and printers for the digitization of 3D objects of cultural heritage. The work describes the full processing chain from the scanning of an exhibit to the creation of a tangible copy using a 3D printer. Problems caused by imperfect data sets are discussed and solutions proposed.

Automatic Merging of 3D Attribute Meshes

In the paper we introduce the method of automatic merging of 3D attribute meshes. Attributes describe the certainty of particular vertices/faces in the mesh. We calculate values of attributes on the basis of the assumed observation strategy as well as the properties of the scanning system. We show the resultant meshes and compare the method to the existing solutions.

Reconstruction of Head Surface Model from Single Scan

The methods for reconstruction of incomelete mesh scanes of faces were presented. The aim is filling the mesh surface with mesh processing methods: surface and volumetric. The problem of fitting elipsoid surface to a single face scan was resolved. The resultant application performes semi-automatic conversion of single scan to the closed mesh model. The comparison of the elipsoid-filling mathod to another method of surface reconstruction using multiple scans was conducted.

Implementation of the Progressive Meshes for Distributed Virtual Museum

This article presents a specific part of the idea of distributed virtual museum. The intention of the authors is to fulfill one of the scenarios for Future Internet and to give a set of requirements for future properties of the global network. A progressive mesh is a lossless approximation of the original mesh model at any, smoothly adjusted, level of detail. The main part of this work is devoted to the extension of progressive meshes for hierarchical representation associated the position of observation. This allows the selective adjustment of the level of detail, measured in the number of triangles that appear in any fragment of the model, independently from the rest. Sample solution was presented, as well as the method of construction and the main criteria for the refinement.

Implementation of the view-dependent progressive meshes for virtual museum

This article presents an idea of a progressive mesh as a lossless approximation of the original mesh, of any, smoothly adjusted, level of detail. The main part of this work is devoted to the extension of progressive meshes for hierarchical representation associated with a dependence on the position of observation. This allows selective adjustment of the level of detail, measured in the number of triangles that appear in any fragment of the model, independently from the rest. Sample solution was presented, method of construction and the main criteria for the refinement. Remaining part of the work is devoted to the implementation of the view-dependent progressive meshes in the ME3D environment, its testing and attempts to estimate the future paths of development.

Rough Rules in Prolog

In this paper we present an approach to develop decision support systems. We focus on knowledge acquisition and processing with the use of rough set theory. The rule knowledge representation is also considered. We discuss the use of Prolog as a tool for knowledge representation and processing. Finally, the way of embedding Prolog code in procedural language programs is presented. Our work is illustrated with an exemplary system supporting credit decisions.

The Accuracy of a Scene Geometry Based on the Terrestrial Laser Scanner Measurements

The article presents the theoretical estimation of the accuracy of the distance measurements between 3D points measured by a scanning system, a description of the experiments carried out and results for Faro X, Z+F Imager and Trimble TX scanners. The result of the experiments shows the correctness of the theoretical estimation and terrestrial laser scanner parameters. The experiments investigated the scanners’ accuracy as applied to the crime scene description. We also present an algorithm for the location of centres of spheres.

Progressive Reduction of Meshes with Arbitrary Selected Points

The usage of progressive meshes for representation and transmission of triangular meshes of faces at certain level of details was described in the paper. We focused on progressive representation based on Garland and Hoppe approach. The comparison of simple methods using quadric mesh simplification to the view-dependent implementation of progressive methods was performed. The mesh simplification is further improved by introducing the characteristic points fixing the distinguishable points on human face. The tests and discussion of the implemented method were given using face scans from 3dMD face scanner.