Optimization of conventional spinning process parameters by means of numerical simulation and statistical analysis

Research in sheet metal spinning has increased due to a greater demand, especially in the transportation industries, for parts with very high strength-to-weight ratios with low cost. Spinning processes are efficient in producing such characteristics and there is great flexibility in the process with a relatively low tool cost. The objectives of this investigation are to define the critical working parameters in spinning, show the effects of these factors on product quality characteristics, and to optimize the working parameters. The example used is the conventional spinning of a cylindrical cup. Optimization of the process is undertaken through the use of statistical analysis tools applied to the data produced from three-dimensional finite element simulations of the process. This has been achieved by generating two ‘designs of experiments’.The first identifies the most critical parameters for product formability and the second shows how these critical parameters affect the product quality. The results show that feed rate,relative clearance, and roller nose radius are the most important working parameters and significantly affect average thickness, thickness variation, and springback of the cylindrical cup. An additional 22 per cent improvement in the product quality characteristic is gained through using the optimum working parameters

Integration of renewable energy sources in the distribution network

Tato práce uvádí obecné informace o obnovitelných zdrojích energie, typech elektráren a jejich pracovních principech. Práce je zaměřena na větrné elektrárny (principy, typy, komponenty, výhody a nevýhody). Obsahuje také pravidla pro připojování rozptýlených zdrojů energie k distribuční soustavě. V praktické části je řešena případová studie, která demonstruje napěťové charakteristiky pro síť vysokého napětí před a po připojení větrné elektrárny do distribuční sítě se dvěma různými hodnotami účiníku.This thesis will provide general information about renewable energy sources, types of power plants and their working principles. The thesis is focused on wind power plants (principles, types, components, advantages and disadvantages). It also includes the rules for connecting dispersed energy sources to the distribution system. In practical part, a case study demonstrates voltage characteristics before and after connection of a wind power plant to a distribution network with two different values of power factor

Complex Event Recognition from Images with Few Training Examples

We propose to leverage concept-level representations for complex event recognition in photographs given limited training examples. We introduce a novel framework to discover event concept attributes from the web and use that to extract semantic features from images and classify them into social event categories with few training examples. Discovered concepts include a variety of objects, scenes, actions and event sub-types, leading to a discriminative and compact representation for event images. Web images are obtained for each discovered event concept and we use (pretrained) CNN features to train concept classifiers. Extensive experiments on challenging event datasets demonstrate that our proposed method outperforms several baselines using deep CNN features directly in classifying images into events with limited training examples. We also demonstrate that our method achieves the best overall accuracy on a dataset with unseen event categories using a single training example.Comment: Accepted to Winter Applications of Computer Vision (WACV'17

When the ANC finally apologises for Zuma, South Africa can move forward

Azad Essa delves into the many scandals that plagued Zuma before his final act and how the ANC turned mostly a blind eye