Improving correlation accuracy of crashworthiness applications by combining the CORA and MADM methods

With the increasing use of Computer Aided Engineering, it has become vital to be able to evaluate the accuracy of numerical models. This research poses the problem of selection of the most accurate and relevant correlation solution to a set of corridor variations. Specific methods such as CORA, widely accepted in industry, are developed to objectively evaluate the correlation between monotonic functions, while the Minimum Area Discrepancy Method, or MADM, is the only method to address the correlation of non-injective mathematical variations, usually related to force/acceleration versus displacement problems. Often, it is not possible to differentiate objectively various solutions proposed by CORA, which this paper proposes to answer. This research is original, as it proposes a new innovative correlation optimisation framework, which can select the best CORA solution by including MADM as a subsequent process. The paper and the methods are rigorous, having used an industry standard driver airbag computer model, built virtual test corridors and compared the relationship between different CORA and MADM ratings from 100 Latin Hypercube samples. For the same CORA value of ‘1’ (perfect correlation), MADM was capable to objectively differentiate between 13 of them and provide the best correlation possible. The paper has recommended the MADM settings n = 1; m = 2 or n = 3; m = 2 for a congruent relationship with CORA. As MADM is performed subsequently, this new framework can be implemented in already existing industrial processes and provide automotive manufacturers and Original Equipment Manufacturers (OEM) with a new tool to generate more accurate computer models.

A new method for the in vivo identification of degenerated material property ranges of the human eye: feasibility analysis based on synthetic data

This paper proposes a new method for in vivo and almost real-time identification of biomechanical properties of the human cornea based on non-contact tonometer data. Further goal is to demonstrate the method’s functionality based on synthetic data serving as reference. For this purpose, a finite element model of the human eye is constructed to synthetically generate full-field displacements from different data sets with keratoconus-like degradations. Then, a new approach based on the equilibrium gap method combined with a mechanical morphing approach is proposed and used to identify the material parameters from virtual test data sets. In a further step, random absolute noise is added to the virtual test data to investigate the sensitivity of the new approach to noise. As a result, the proposed method shows a relevant accuracy in identifying material parameters based on full-field displacements. At the same time, the method turns out to work almost in real time (order of a few minutes on a regular workstation) and is thus much faster than inverse problems solved by typical forward approaches. On the other hand, the method shows a noticeable sensitivity to rather small noise amplitudes rendering the method not accurate enough for the precise identification of individual parameter values. However, analysis show that the accuracy is sufficient for the identification of property ranges which might be related to diseased tissues. Thereby, the proposed approach turns out promising with view to diagnostic purposes.

On the development of a virtual test bench to assess sound absorption of materials in an alpha chamber

A description is given of a virtual test-bench (VTB) designed by engineering center of Peter the Great St. Petersburg Polytechnic University to calculate a sound absorption coefficient of various materials. Developed VTB differs from known programs in that it allows a sound absorption coefficient of various materials to be determined with minimum involvement of an engineer. This VTB differs from other programs also by using infinite elements jointly with finite elements, which increases adequacy of the discrete model being used, and also the configuration of the boundary of an alpha chamber being used. The known programs use various phenomenological mathematical models of porous materials such as Johnson-Champoux-Allard (JCA) model. The VTB is based on fundamental mathematical models and statistical energy analysis (SEA) that allow describing adequately the established or transitional processes of sound absorption and reflection by a porous material the properties of which are not homogenized. The value of this VTB, which is created on the basis of a VA One software complex supplemented by a set of files of boundary conditions, files of solvers’ settings, secondary finite element (FE) models, is that VTB allows standardized calculations to be performed to determine the sound absorption coefficient of a material with minimum involvement of an engineer and the obtained result to be submitted for detailed processing. Developed virtual test-bench enables determination of a sound absorption coefficient for various materials within the entire finite frequency range. The result of the calculation is displayed as a graph of dependency of the material sound absorption coefficient on frequency.

AN INTEGRATED SOLUTION FOR THE ONLINE MARKETING OF CUSTOM-MADE GARMENTS THAT INCORPORATES A VIRTUAL FITTING ROOM

We use IT applications to solve various problems, such as buying various things, communication or professional matters. Everything seems to be solved faster when we shop on online platforms (virtual stores) because we can analyse several offers, see the best deals and then decide which one suits our purpose. Sometimes the items bought online are returned for the following reasons: they do not look as they were presented on the website; these items have functional problems or do not fit (this is the situation with clothing and footwear products). Usually, the fit problems occur because the customer did not choose the right size, the model does not have a size range that fits the customer, or the customer has a particular body shape. The return rate (fit problem) can decrease if the customer can virtually try on the selected model during the purchase process to check how it looks on their body. Assuming that customers also have the option to personalise the product according to their body shape or desires, their satisfaction increases. In this case, the number of returned or unsold products is reduced, and a dynamic and positive advertising campaign for the brand can be carried out (based on customer reviews). This paper proposes an integrated solution for online marketing of customised clothing products (website for medium or small companies), using a virtual test room that simulates the product on the virtual mannequin in different positions (360°).

Gamification of Neuropsychological Tools as a Multi-Sensory Approach to Education. Stroop's Paradigm

The Stroop test is a neuropsychological assessment that is worldwide recognized for its sensitivity and reliability in assessing frontal activation and executive function control. The Stroop test was conducted in this research effort using the Unity machine in a virtual test with the identical application approach and outcome measurement as in the physical test. The new visual "ustroop" test was conducted to a large enough sample of persons to allow comparisons to the initial test. Subsequently, more game scenarios in the form of a play script were added to evaluate the player's reaction to color, brand name, and words. To summarize, neuropsychological evaluation techniques can be used to promote and evaluate visual gaming, and the current project's findings can be developed upon. Though, scientific fields such as cognitive neuroscience, neuropsychological assessment tools, and gamification techniques can effectively increase learning and cognitive function through continual exercise and can be an asset in the educational process.

A Replicable Methodology to Evaluate Passive Façade Performance with SMA during the Architectural Design Process: A Case Study Application

Huge efforts have been made in recent decades to improve energy saving in the building sector, particularly focused on the role of façades. Among the explored viable solutions, climate-adaptive building shells [CABS] consider promising solutions to control solar radiation, both in terms of illuminance and heating levels, but are still piloting these solutions due to their complex designs and necessary costs. The present study aims to provide a speedy but reliable methodology to evaluate the potential impacts of adopting active/passive CABS systems during the preliminary design stage. The proposed methodology allows the evaluation and comparison, when multiple options are considered, of the effects of each solution in terms of the energy needs, thermal comfort and lighting, while reducing the required effort and time for an extensive analysis of the overall building level. This is based on the use of a “virtual test room” where different conditions and configurations can be explored. A case study in the city of Bologna is included for demonstration purposes. The achieved results support the decisions made regarding energy behavior (over/under heating), indoor comfort, lighting and energy at an early design stage.

A Novel Perspective for Examining and Comparing Real and Virtual Test Tasks Performed by the Dominant and Non-Dominant Hand in Healthy Adults

This study presents a novel perspective for the study of functional lateralization in a virtual reality environment. In the model study of handedness, the recognition of the dominant and non-dominant hand in real and virtual conditions was assessed using selected tests, such as a real light exposure test of Piórkowski’s apparatus and classical clinical tests, as well as virtual test tasks, in healthy adults. Statistically significant differences between the dominant and non-dominant hand were observed for tests carried out both in classical conditions and the virtual environment. The results and findings of other studies suggest that the virtual reality approach is a very promising and sensitive tool in the research on functional asymmetries in healthy and disease for motor skills and cognition processes.