A further inquiry into the theory of s-transformations and criterion matrices

Civil Engineering and GeosciencesCivil Engineering and Geoscience

A FPGA implementation of a real-time inspection system for steel roll imperfections

Today’s production processes are more and more optimized to be competitive. The production demands are increased for speed and quality. These increased demands do not pass the roll shops in the steel industry. In the roll shop periodically the rolls from the rolling mill are checked for imperfections. The imperfections are detected by special inspection systems. Improving the inspection systems can speed up the overall process significantly in the roll shop. The request for an improved inspection system results in a new generation inspection system. This inspection system should measure more signals at the same time and process the signals faster. To achieve this result the measurements are digitalized and processed in parallel on a FPGA. Speed and quality demands are also asked from the engineers by designing and maintanance of the inspection system. In this thesis a High-Level Synthesis tool is selected to implement the mathematical model of the inspection system. The tool selection is done based on a comparison between three HLS tools, namely: CatapultC, ROCCC and Compaan. For this implementation Compaan is the most promising one. Compaan is able to split the data streams processing in concurrent systems with distributed memories. With Compaan as development tool the main part of the mathematical model is implemented in four months. This is four times faster than the preceding implementation.Circuits and SystemsElectrical Engineering, Mathematics and Computer Scienc

Frameworks for Generalization Constraints and Operations Based on Object-Oriented Data Structure in Database Generalization

The constraints and the operations play an important role in database generalization. They guide and govern database generalization. The constraints are translation of the required conditions that should take into account not only the objects and relationships among objects but also spatial data schema (classification and aggregation hierarchy) associated with the final the existing database. The operations perform the actions of generalization in support of data reduction in the database. The processes of generalization should be performed a series of operations under the control of constraints. The constraints in database generalization are still lack of research. There is also the lack of frameworks to express the constraints and the operations on the basis of object-oriented data structure in database generalization. This paper focuses on the frameworks for generalization operations and constraints based on object-oriented data structure in database generalization. The constraints as the attributes of the object and the operations as the methods of the object can be encapsulated in classes. They have the inheritance and polymorphism property. So the framework of the constraints and the operations which are based on object-oriented data structure can be easily understood and implemented. The constraint and the operations based on object-oriented database are proposed based on object-oriented database. The frameworks for generalization operations, constraints and relations among objects based on object-oriented data structure in database generalization are designed. The categorical database generalization is concentrate on in our paper

Investigation of the resilient behavior of granular base materials with simple test apparatus

In many developing countries, where resources are at premium, thin asphalt layers or chip seals are widely used to provide a durable all weather pavement surfacing. In such pavements the role of granular layers is very important in the general performance of the structure. Pavement designs in these countries are empirical in nature and rely on simple input parameters like California Bearing Ratio (CBR) values. Although widely applicable the traditional CBR test does not provide the mechanical properties such as resilient and permanent deformation characteristics of granular road materials. This paper documents the characterization technique developed to determine the mechanical behavior of granular (sub-) base materials based on CBR test using repeated load cycles. The confining pressure developed in the complex CBR stress state is estimated using strain gauges. Finite Element analysis has been attempted to model the repeated load CBR (RL-CBR) and derive an equivalent resilient modulus. Furthermore, a large scale cyclic load triaxial test was carried out on coarse unbound granular materials (UGMs) to validate the result of the RL-CBR. The RL-CBR test reasonably estimates the resilient modulus of UGMs which can be used as an input in mechanistic pavement design analysis in the absence of triaxial testing facilitiesStructural EngineeringCivil Engineering and Geoscience

Power and Thermal Cycling Testbed for End of Life Assessment of Semiconductor Devices

The reliability of semiconductor power devices can be studied by performing a thermal and power cycling test. In order to create the desired temperature cycles, there are four free variables to select during the power cycling test, namely the heating current, heating time, cooling time, and heatsink temperature. In this paper, the relation between the selected variables and the minimum and maximum junction temperature is extensively tested for the silicon IGBT with serial number IKP06N60T. Furthermore, the thermal model is discussed and verified and a rough estimate of the electrical resistance, thermal time constant, thermal resistance, and thermal capacitance are calculated.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.DC systems, Energy conversion & Storag

Pattern classification approaches to matching building polygons at multiple scales

Matching of building polygons with different levels of detail is crucial in the maintenance and quality assessment of multi-representation databases. Two general problems need to be addressed in the matching process: (1) Which criteria are suitable? (2) How to effectively combine different criteria to make decisions? This paper mainly focuses on the second issue and views data matching as a supervised pattern classification. Several classifiers (i.e. decision trees, Naive Bayes and support vector machines) are evaluated for the matching task. Four criteria (i.e. position, size, shape and orientation) are used to extract information for these classifiers. Evidence shows that these classifiers outperformed the weighted average approach.OTB ResearchOTB Research Institute for the Built Environmen

Self healing of road-use bituminous materials: Mechanical characterization and its modelling (abstract)

Structural EngineeringCivil Engineering and Geoscience

Generating electricity at a breakwater in a moderate wave climate

A new concept for wave energy conversion is examined as a proof of concept for generating electricity in a moderate wave climate while being integrated in a caisson breakwater. Physical model testing is performed to analyse the preliminary efficiency of the device and to identify areas of improvement. The resulting device is calculated for two sample locations in order to gain an understanding of its feasibility. Recommendations are made for continued research and possible improvements of the design.Hydraulic EngineeringCivil Engineering and Geoscience

Influence of changes in surface layer properties on tire/pavement noise

This paper investigates changes in tire/pavement noise caused by variations in the road surface characteristics. This research is based on the analysis of noise and surface characteristics collected from sections with 25 mm thickness thin layer surfacings in the Netherlands. Investigations are first performed on the measured noise levels in 1/3rd octave bands, texture levels and the sound absorption curves. The one-way analysis of variance is employed to test the changes of noise caused by variations of the pavement surface characteristics. It is found that the significant differences in the noise levels between road surfaces mainly appear at frequencies higher than 1000 Hz, and they are considered to be related to surface layer properties. Multivariate linear regression analysis is performed for describing the relationship between the noise level changes and the variations of surface characteristics. By using the partial least square (PLS) regression, the combined effect of texture and sound absorption coefficients on different spectral bands is displayed. From the regression results, it can be inferred that the sound absorption variations at 1000 and 1250 Hz are important factors influencing noise reduction of thin layer surfacings. The founding provides information for designing the noise reducing thin layer surfacings.Structural EngineeringCivil Engineering and Geoscience

Silicofluoride-plant: Van fluorwasser tot eindprodukt

DelftChemTechApplied Science