Exploring Customer Specific KPI Selection Strategies for an Adaptive Time Critical User Interface

Rapid growth in the number of measures available to describe customer-organization relationships has presented a serious challenge for Business Intelligence (BI) interface developers as they attempt to provide business users with key customer information without requiring users to painstakingly sift through many interface windows and layers. In this paper we introduce a prototype Intelligent User Interface that we have deployed to partially address this issue. The interface builds on machine learning techniques to construct a ranking model of Key Performance Indicators (KPIs) that are used to select and present the most important customer metrics that can be made available to business users in time critical environments. We provide an overview of the prototype application, the underlying models used for KPI selection, and a comparative evaluation of machine learning and closed form solutions to the ranking and selection problems. Results show that the machine learning based method outperformed the closed form solution with a 66.5% accuracy rate on multi-label attribution in comparison to 54.1% for the closed form solution

A brain-wave equation incorporating axo-dendritic connectivity

We introduce an integral model of a two-dimensional neural field that includes a third dimension representing space along a dendritic tree that can incorporate realistic patterns of axo-dendritic connectivity. For natural choices of this connectivity we show how to construct an equivalent brainwave partial differential equation that allows for effcient numerical simulation of the model. This is used to highlight the effects that passive dendritic properties can have on the speed and shape of large scale traveling cortical waves

Enhancement of the interface of friction welded steel-aluminium joints

Lightweight multi-material components are of great importance for the transport industry. Not only the component’s weight can be decreased, but also its local properties can be adapted to different loading profiles. Tailored Forming is a novel concept for producing multi-material components. By using a joining process, the creation of a bond between different materials takes place in the first step of the process chain. In the subsequent steps, multi-material workpieces are processed in their joined state while maintaining or improving the joint strength. This study focuses on steel-aluminium joints, which were created by friction welding and further processed by induction heating and impact extrusion. A counter pressure superposition mechanism was implemented in the extrusion tooling to control the stress state during plastic deformation. Flow behaviours of steel and aluminium are largely different at a given temperature, which necessitates a near step-function temperature distribution in the hybrid billet to obtain matching flow stresses. An inductive heating strategy was developed which led to a temperature gradient in the billets before extrusion. Extruded billets were analysed by destructive testing methods and metallography. The bond could be maintained after extrusion when counter pressure superposition was used; but no improvement could be obtained. Without counter force superposition, however, cracks were observed in the joining interface and the joint strength decreased. This paper discusses the aforementioned findings in the current process design and makes suggestions on how the involved processes should be reconfigured to improve the joint strength. © 2020, The Author(s)

Comparison of the Joining Zone Development of Hybrid Semi-Finished Products after Different Extrusion Processes

The use of hybrid semi-finished products made of aluminium and steel enables the production of components with locally adapted properties, i.e. high strength and wear-resistance with reduced weight. In the scope of this work, different impact extrusion processes for the forming of friction-welded hybrid semi-finished products consisting of steel (20MnCr5) and aluminium (EN AW-6082) were developed and experimentally implemented. The resulting material flows were intended to enable different joining zone geometries as well as to evaluate the influence of a thermo-mechanical treatment during the impact extrusion process on the quality of the joining zone. For this purpose, a full-forward extrusion, cup-backward extrusion, combined cup-backward-full-forward extrusion and a hollow-forward extrusion process were investigated. The evaluation of the resulting component quality was carried out based on metallographic images, which provide microstructural information about the forming-related influence on the friction welded joining zone. Based on the characteristic values determined, a correlation between the reproducibility and quality of the joining zone properties and the type of impact extrusion process is deduced. The backward extrusion processes have proven to be the best processes in terms of influencing the joining zone geometry. Further, the effect of forward extrusion showed no significant influence on the joining zone geometry, even resulting in a reduction of the joining zone formation in the combined cup-backward-full-forward extrusion process

Climate change favours large seasonal loss of Arctic ozone

Chemical loss of Arctic ozone due to anthropogenic halogens is driven by temperature, with more loss occurring during cold winters favourable for formation of polar stratospheric clouds (PSCs). We show that a positive, statistically significant rise in the local maxima of PSC formation potential (PFP^LM) for cold winters is apparent in meteorological data collected over the past half century. Output from numerous General Circulation Models (GCMs) also exhibits positive trends in PFP^LM over 1950 to 2100, with highest values occurring at end of century, for simulations driven by a large rise in the radiative forcing of climate from greenhouse gases (GHGs). We combine projections of stratospheric halogen loading and humidity with GCM-based forecasts of temperature to suggest that conditions favourable for large, seasonal loss of Arctic column O3 could persist or even worsen until the end of this century, if future abundances of GHGs continue to steeply rise

Contact geometry modification of friction-welded semi-finished products to improve the bonding of hybrid components

To improve the bond strength of hybrid components when joined by friction welding, specimens with various front end surface geometries were evaluated. Rods made of aluminum AA6082 (AlSi1MgMn/EN AW-6082) and the case-hardening steel 20MnCr5 (AISI 5120) with adapted joining surface geometries were investigated to create both a form-locked and material-bonded joint. Eight different geometries were selected and tested. Subsequently, the joined components were metallographically examined to analyze the bonding and the resulting microstructures. The mechanical properties were tested by means of tensile tests and hardness measurements. Three geometrical variants with different locking types were identified as the most promising for further processing in a forming process chain due to the observed material bond and tensile strengths above 220 MPa. The hardness tests revealed an increase in the steel’s hardness and a softening of the aluminum near the transition area. Apparent intermetallic phases in the joining zone were analyzed by scanning electron microscopy (SEM) and an accumulation of silicon in the joining zone was detected by energy-dispersive X-ray spectroscopy (EDS). © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Tailored Forming of hybrid bulk metal components

Multi-material bulk metal components allow for a resource efficient and functionally structured component design, with a load adaptation achieved in certain functional areas by using similar and dissimilar material combinations. One possibility for the production of hybrid bulk metal components is Tailored Forming, in which pre-joined semi-finished products are hot-formed using novel process chains. By means of Tailored Forming, the properties of the joining zone are geometrically and thermomechanically influenced during the forming process. Based on this motivation, forming processes (die forging, impact extrusion) coupled with adapted inductive heating strategies were designed using numerical simulations and successfully realised in the following work in order to produce demonstrator components with serial or coaxial material arrangements. The quality of the joining zone was investigated through metallographic and SEM imaging, tensile tests and life cycle tests. By selecting suitable materials, it was possible to achieve weight savings of 22% for a pinion shaft and up to 40% for a bearing bush in the material combination of steel and aluminium with sufficient strength for the respective application. It was shown that the intermetallic phases formed after friction welding barely grow during the forming process. By adjusting the heat treatment of the aluminium, the growth of the IMP can also be reduced in this process step. Furthermore, for steel-steel components alloy savings of up to 51% with regard to chromium could be achieved when using low-alloy steel as a substitute for high-alloy steel parts in less loaded sections. The welded microstructure of a cladded bearing washer could be transformed into a homogeneous fine-grained microstructure by forming. The lifetime of tailored formed washers nearly reached those of high-alloyed mono-material components

Maar-diatreme geometry and deposits: Subsurface blast experiments with variable explosion depth

Basaltic maar-diatreme volcanoes, which have craters cut into preeruption landscapes (maars) underlain by downward-tapering bodies of fragmental material commonly cut by hypabyssal intrusions (diatremes), are produced by multiple subsurface phreatomagmatic explosions. Although many maar-diatremes have been studied, the link between explosion dynamics and the resulting deposit architecture is still poorly understood. Scaled experiments employed multiple buried explosions of known energies and depths within layered aggregates in order to assess the effects of explosion depth, and the morphology and compaction of the host on the distribution of host materials in resulting ejecta, the development of subcrater structures and deposits, and the relationships between them. Experimental craters were 1–2 m wide. Analysis of high-speed video shows that explosion jets had heights and shapes that were strongly influenced by scaled depth (physical depth scaled against explosion energy) and by the presence or absence of a crater. Jet properties in turn controlled the distribution of ejecta deposits outside the craters, and we infer that this is also reflected in the diverse range of deposit types at natural maars. Ejecta were dominated by material that originated above the explosion site, and the shallowest material was dispersed the farthest. Subcrater deposits illustrate progressive vertical mixing of host materials through successive explosions. We conclude that the progressive appearance of deeper-seated material stratigraphically upward in deposits of natural maars probably records the length and time scale for upward mixing through multiple explosions with ejection by shallow blasts, rather than progressive deepening of explosion sites in response to draw down of aquifers