Minimization of stock weight during close-die forging of a spindle

In this paper, Finite Element method and full-scale experiments have been used to study a hot forging method for fabri-cation of a spindle using reduced initial stock size. The forging sequence is carried out in two stages. In the first stage, the hot rolled cylindrical billet is pre-formed and pierced in a closed die using a spherical nosed punch to within 20 mm of its base. This process of piercing or impact extrusion leads to high strains within the work piece but requires high press loads. In the second stage, the resulting cylinder is placed in a die with a flange chamber and upset forged to form a flange. The stock mass is optimized for complete die filling. Process parameters such as effective strain distribution, material flow and forging load in different stages of the process are analyzed. It is concluded from the simulations that minor modifications of piercing punch geometry to reduce contact between the punch and emerging vertical walls of the cylinder appreciably reduces the piercing load. In the flange chamber, a die surfaces angle of 52° instead of 45° is pro-posed to ensure effective material flow and exert sufficient tool pressure to achieve complete cavity filling. In order to achieve better compression, it is also proposed to shorten both the length of the inserted punch and the die “tongues” by a few mm.

Comparison of two HVAC renovation solutions : A case study

Within the aging building stock of Europe, there is great potential of saving energy through renovation and upgrading to modern standards, and to thereby approach the internationally set goals of lower energy use. This paper concerns the planned renovation of the building envelope and HVAC systems in a multi-family house in Ludwigsburg, Germany. Five systemic HVAC solutions were compared, with special focus on two systems: A) Balanced ventilation with HRC + Micro heat pump, and B) Forced exhaust ventilation + Heat pump with exhaust air HRC + Ventilation radiators. Given the predicted heating demand and ventilation rate of the house after renovation, the performance of the two systems was compared, alongside three common systems for reference. Calculations were made using TMF Energi, a tool developed by SP Technical Research Institute of Sweden.    Both systems A and B were found to have the lowest electrical energy use together with the ground source heat pump system for the assumed conditions. For other assumptions, including different climate and degree of insulation, some differences between these three systems were noted. Most significant is the increased electrical use of system B for higher heating loads due to limitations in the power available from the heat source, exhaust air, which is dependent on the ventilation rate.

Financial time series analysis : Chaos and neurodynamics approach

This work aims at combining the Chaos theory postulates and Artificial Neural Networks classification and predictive capability, in the field of financial time series prediction. Chaos theory, provides valuable qualitative and quantitative tools to decide on the predictability of a chaotic system. Quantitative measurements based on Chaos theory, are used, to decide a-priori whether a time series, or a portion of a time series is predictable, while Chaos theory based qualitative tools are used to provide further observations and analysis on the predictability, in cases where measurements provide negative answers. Phase space reconstruction is achieved by time delay embedding resulting in multiple embedded vectors. The cognitive approach suggested, is inspired by the capability of some chartists to predict the direction of an index by looking at the price time series. Thus, in this work, the calculation of the embedding dimension and the separation, in Takens‘ embedding theorem for phase space reconstruction, is not limited to False Nearest Neighbor, Differential Entropy or other specific method, rather, this work is interested in all embedding dimensions and separations that are regarded as different ways of looking at a time series by different chartists, based on their expectations. Prior to the prediction, the embedded vectors of the phase space are classified with Fuzzy-ART, then, for each class a back propagation Neural Network is trained to predict the last element of each vector, whereas all previous elements of a vector are used as features.

Anton Nyström's Defense of Homosexuality

In 1919 Anton Nyström became the first person in Sweden to publish a comprehensive defense of homosexuality. He believed that its classification as a mental illness was erroneous and that Sweden's law against homosexual sex was both irrational and cruel. Nyström was a physician whose work in the medical area dealt primarily with dermatology, psychiatry and human sexuality; however he was also a prolific historian, who took a staunchly anti-Christian view in his analysis of how Christianity affected European culture, especially in the area of sexual morality. In fact, much of Nyström's medical texts dealing with human sexuality consisted of anti-Christian cultural and historical commentary. The object of this "C-uppsats" is to analyze Nyström's pamphlet, Om Homosexualitet och Hermafroditi: Belysning af Missförstådda Existenser and illustrate how its defensive structure was consistent with the pattern used by the author in his other books and articles on human sexuality. Specifically, that irrational and neurotic Christian beliefs caused both mental and physical suffering and were the source of deleterious forms of morality. Additionally, this paper will also show that the solution Nyström had for the problem of negative and erroneous attitudes towards homosexuality was to replace the sodomitic view of homosexuality with one based upon a more rational and naturalistic belief system, the basis of which could be found in the pre-Christian cultures of Europe, most especially in Greece. This new conception was to be constructed primarily out of historical example and cultural analyses. For Nyström, history writing was used both as a weapon to fight the source of negative attitudes towards homosexuality, as well as a tool that could be used to build a positive cultural model which would be beneficial for homosexuals.