Model Generation

Résumé Cet article présente un modèle de croissance schumpetérien, qui géné-ralise la théorie existante : nous utilisons la différenciation circulaire du modèle de Salop [1979] pour prendre en compte le fait que la connaissance se diffuse, avec plus ou moins d'ampleur, entre les ...

This study presents the significance of the currency crises, discusses the related literature and applies a model of economic vulnerability to Turkey during 1985Q2-2004Q2. The common approach in currency crisis literature is to focus on the performance of ...

Within the (E-)Power research program a new approach for supporting the chain of processes from the creation of legal texts to the implementation of normative (juridical) information systems has been developed. According to this approach cre- ating formal knowledge models starts with the analysis of the legal text. This process executed by knowledge analysts is very time consuming. Within the

Complex models generated e.g. with a laser range scanner often consist of several thousand or million triangles. For efficient rendering this high number of primitives has to be reduced. An important property of mesh reduction - or simplification - algorithms used for rendering is the control over the introduced geometric error. In general, the better this control is, the slower the simplification algorithm becomes. This is especially a problem for out-of-core simplification, since the processing time quickly reaches several hours for high-quality simplification. In this paper we present a new efficient algorithm to measure the Hausdorff distance between two meshes by sampling the meshes only in regions of high distance. In addition to comparing two arbitrary meshes, this algorithm can also be applied to check the Hausdorff error between the simplified and original meshes during simplification. By using this information to accept or reject a simplification operation, this method all...

Physically based models are commonly used as an integral step in landslide hazard assessment. Geomorphic principles can be applied to a broad area, resulting in first order assessment of landslide susceptibility. New techniques are now available that may result in the increased accuracy of such models. We investigate the possibility to enhance landslide susceptibility modeling by integrating two physically-based landslide models, the Factor of Safety (FS) and the Shallow Stability model (SHALSTAB), with traditional empirical-statistical methods that utilize terrain attribute information derived from a digital elevation model and land use characteristics related to forest harvesting. The model performance is measured by the area under the receiver operating characteristic curve (AUROC) and sensitivity at 90% and 80% specificity both estimated by bootstrap resampling. Our study examines 278 landslide initiation points in the Klanawa Watershed located on Vancouver Island, British Columbia, Canada. We use a generalized additive model (GAM)and a logistic regression model (GLM) combining physical landslide models, terrain attributes and land use data, and GAMs and GLMs using only subsets of these variables.In this study, all empirical and combined physical-empirical models outperformthe physically-based models, with GAMs often performing significantly better than GLMs. The strongest predictive performance is achieved by the GAMsusing terrain attributes in combination with land use data. Variables representing physically-based models do not significantly improve the empirical models, but they may allow for a better physical interpretation of empirical models. Also, based on bootstrap variable-selection frequencies,land use data, FS, slope and plan/profile curvature are relatively the most important predictor variables.

In September 2009, Tropical Storm Ketsana (local name: TS Ondoy) hit the Manila metropolitan area (Metro Manila) and brought an anomalous volume of rain that exceeded the Philippines’ forty-year meteorological record. The storm caused exceptionally high and extensive flooding. Part of this study was a survey conducted along the stretch of the Marikina River, one of the major rivers that flooded. Post event resident interviews were used to reconstruct the flooding in the absence of stream gauge data. Hydraulic and hydrologic modeling were carried out to understand the mechanism that brought the flood. Peak floods occurred at different hours along the river resulting from the transmission of water from the main watershed to the downstream areas. Modeled peak flood and flood timing coincided well with actual observations except for downstream stations where actual peak floods were observed to have occurred at a later time. Compounding factors such as other flood sources and stream back...

This paper proposes to combine a heuristic technique and an algorithmic one to provide a method to reverse engineer the generalization/specialization links hidden in a relational database. The heuristic phase combines the exploration of three sources: DDL specifications, DML specifications and data to provide information, such as inclusion links and existence constraints. This information is then used by the algorithm

Relational Data Base Management Systems (RDBMS) are currently the most popular database management systems. The relational model is a simple and powerful model for representing real world applications. However, it lacks the expressiveness of conceptual models. Unlike the latter, the relational model does not offer the generalization abstraction. Therefore, it does not allow the designer to represent directly a large

This paper describes the simulation studies of a 3-Ø self-excited asynchronous generator (SEASG) fed RL load in conjunction with an AC/DC/AC converter fed series RLC circuit. An attempt has been made to analyze the current, drawn by the rectifier circuit due to changes in the inverter frequency and their effects on the terminal voltage of the generator have been studied in open loop control. The frequency variation of the inverter fed series RLC circuit emulate the phenomenon of an inductive, capacitive reactance and resistive effect at the point of common coupling (PCC) of the generator terminal. This methodology could be used to inject leading / lagging VAR into the self-excited induction generator network (stand alone power generator), used to extract the power from wind, solar, Mini/Micro hydro energy sources. The proposed system has been simulated using power system tool box in Matlab/Simulink software. An attempt has been made to study the performances of SEASG using simulation. The results have been discussed and also presented.

Relational Data Base Management Systems (RDBMS) are currently the most popular database management systems. The relational model is a simple and powerful model for representing real world applications. However, it lacks the expressiveness of conceptual models. Unlike the latter, the relational model does not offer the generalization abstraction. Therefore, it does not allow the designer to represent directly a large

An extensively revised heuristic-analytic theory of reasoning is presented incorporating three principles of hypothetical thinking. The theory assumes that reasoning and judgment are facilitated by the formation of epistemic mental models that are generated one at a time (singularity principle) by preconscious heuristic processes that contextualize problems in such a way as to maximize relevance to current goals (relevance principle). Analytic processes evaluate these models but tend to accept them unless there is good reason to reject them (satisficing principle). At a minimum, analytic processing of models is required so as to generate inferences or judgments relevant to the task instructions, but more active intervention may result in modification or replacement of default models generated by the heuristic system. Evidence for this theory is provided by a review of a wide range of literature on thinking and reasoning.

Software testing is one of the most widely used methods for quality assurance and fault detection purposes. However, it is one of the most expensive, tedious and time consuming activities in software development life cycle. Code-based and specification-based testing has been going on for almost four decades. Model-based testing (MBT) is a relatively new approach to software testing where the

ABSTRACT The paper proposes the use of ultracapacitor storage device in order to support the mismatch between the available PV source power and microgrid load requirement. A realistic simulation scheme was implemented to evaluate the hybrid power system behaviour under varying microgrid load requirements. The operating performance were observed in steady state and transient conditions. The action of the ultracapacitor was pointed out, while the PV source operated at the maximum power point. Some discussions about the behaviour of the components and system operating characteristics were reported. The growing trend in both energy market deregulation and environmental preservation is forcing studies and applications of Distributed Generation (DG). DG, connected to local loads and distribution grids, is an extremely interesting issue. It offers the opportunity of constructing smart- and micro-grids, which are emerging as an integral feature of the future power systems. Microgrids are clusters of loads and micro sources operating as a single controllable power system. Microgrids can operate in parallel with the grid, as an autonomous power island, or in transition between grid- connected mode and islanded mode of operation. In the non-autonomous mode, the microgrid produces power while interconnected to the utility system. In the autonomous mode, the microgrid serves its electrical load without drawing power from the distribution utility. When possible, micro generation units are dispatched on the minimization of variable costs for service providing. So, real-time optimization in microgrids is performed through frequent adjustments of generator outputs to