High Detailed Model Research Articles

An international standard conceptual model for sharing references to hydrologic features

Summary Concepts such as catchment, basin, watershed and river are commonly understood in many fields of discourse, but are described differently according to the focus on various aspects of the hydrology phenomenon. The effective exchange of hydrologic data containing references to hydrologic features requires standardised semantics of the concepts that allow identification of these features. Here, the scope of common approaches to information modelling of hydrologic features is examined, and is compared to the requirements for feature identification in multiple contexts. A conceptual model is presented that reconciles the underlying differences in representation of hydrologic features and levels of detail in typical datasets. By providing a stable and common referencing system for hydrologic features, the model will assist in the organization of observation and modelling of such features, and in the aggregation of generated data on a global, regional, national or basin scale. The model encompasses a number of approaches used in different contexts to identify and model hydrologic features and enforce the semantics of relationships between different levels of detail. Thus, it provides a semantic framework for common feature identifiers to be developed and embedded in individual data products, while providing the flexibility to model complex hydrological processes at fine detail. The common identifiers can be used in aggregating data generated using high-detail models of processes, and in partitioning large and complex hydrologic feature datasets into local study areas. Different local models can be applied according to the dominant hydrologic processes and the amount of hydrometric monitoring available for each region. The model is intended to form the basis for standard practices under the auspices of the World Meteorological Organization Commission for Hydrology. It is presented here to invite further testing, feedback and engagement in the process of its acceptance and implementation as an international standard for hydrologic feature identification. Based on the accepted International Organization for Standardization General Feature Model, it will be possible to realise, in a standardised way, the semantics of feature identification in tools for managing metadata documenting hydrologic datasets and products.

Proposal of an Information System for a Semi-automatic Virtual Reconstruction of Archeological Sites

In some business areas there is the need to use representations of places or buildings in order to provide visual informations. These representations are, mainly, reconstructions of scaled real models or virtual representations produced in a Computer-Aided Design (CAD) tool. Recently, procedural modeling has been applied to generate buildings and cities in a short time and with a minimum user intervention. This methodology reveals to be a promising solution for a cost–effective alternative in models construction. One of the areas that can benefit from this kind of approach is archeology, for example to test archeological hypothesis. However, the existing solutions are not flexible enough to provide high detailed models containing building interiors and exteriors. This paper aims to present the global architecture and specification of an information system that supports the procedural modeling process, producing enhanced virtual representations of ancient places, including building facades and interiors, using the information available.

Algorithms for construction digital 3D models for unique objects

Problems of development and analysis of construction high-detailed digital models of an object surface are addressed. It is also supposed that simulated objects are not standard; i.e., they are bounded by a surface of a complex form, and their digital representation require generating a very large number of points. Special attention is paid to problems of constructing a hierarchical structure of algorithms, including the analysis of various strategies of condensing points and surface approximation. For a number of examples, the capabilities of the developed technique are demonstrated for various objects and different types of imagery.

Incremental Error Analysis of 3D Polygonal Model through MAYA API

Generally applications in computer graphics use very high detailed models. These models are too compound for the limited hardware capacity and take much time to render and to transmit. Related fields can benefit from simplification of complex polygonal models. This introduces errors in the models during the process of simplification. It is require to judge when to stop the simplification process as rate of error change in the model is not same in every step of simplification process. It is required to measure the error in the model during simplification to judge the quality of the 3D model at every stage. It is proposed to measure the error in the model at every stage and analyze the rate of change of error in the model as a valuable tool for managing data complexity. This algorithm is implemented on 4 different sets of models. Each set contains models at different number of polygon levels. Experiments are repeated to measure error on them at each level. In order to gain in both memory and speed, VC++ API is developed and created a MLL (Maya link library) to load as a plug-in in Maya.

Seasonal Forcing Drives Spatio-Temporal Pattern Formation in Rabies Epidemics

Seasonal forcing is identifled as a key pattern generating mechanism in an epi- demic model of rabies dispersal. We reduce an established individual-based high-detail model down to a deterministic conceptual model. The characteristic wave pattern characterized by high densities of infected individuals is maintained throughout the reduction process. In our model it is evident that seasonal forcing is the dominant factor that drives pattern formation. In particular we show that seasonal forcing can cause splitting of epidemic wave fronts.