Filtern
Erscheinungsjahr
Dokumenttyp
- Konferenzveröffentlichung (216) (entfernen)
Sprache
- Englisch (216) (entfernen)
Schlagworte
- Bionik (3)
- Gespenstschrecken (3)
- Haftorgan (3)
- adhesion (3)
- stick insects (3)
- Competency-Oriented Exams (2)
- Field measurement (2)
- Solar modules (2)
- 360° Panorama (1)
- AEM-Electrolysis (1)
Institut
- Westfälisches Institut für Gesundheit (49)
- Institut für Internetsicherheit (45)
- Westfälisches Energieinstitut (24)
- Informatik und Kommunikation (21)
- Maschinenbau Bocholt (20)
- Elektrotechnik und angewandte Naturwissenschaften (19)
- Wirtschaft und Informationstechnik Bocholt (7)
- Institut für biologische und chemische Informatik (6)
- Fachbereiche (2)
- Institut Arbeit und Technik (2)
- Wirtschaftsingenieurwesen (2)
- Institut für Innovationsforschung und -management (1)
- Mechatronik-Institut Bocholt (1)
- Strategische Projekte (1)
- Wirtschaftsrecht (1)
Advanced Determination of Temperature Coefficients of Photovoltaic Modules by Field Measurements
(2023)
In this work data from outdoor measurements, acquired over the course of up to three years on commercially available solar panels, is used to determine the temperature coefficients and compare these to the information as stated by the producer in the data sheets. A program developed in MatLab App Designer allows to import the electrical and ambient measurement data. Filter algorithms for solar irradiance narrow the irradiance level down to ~1000 W/m2 before linear regression methods are applied to obtain the temperature coefficients. A repeatability investigation proves the accuracy of the determined temperature coefficients which are in good agreement to the supplier specification if the specified values for power are not larger than -0.3%/K. Further optimization is achieved by applying wind filter techniques and days with clear sky condition. With the big (measurement) data on hand it was possible to determine the change of the temperature coefficients for varying irradiance. As stated in literature we see an increase of the temperature coefficient of voltage and a decline for the temperature coefficient of power with increasing irradiance.
Inspired by the super-human performance of deep learning models in playing the game of Go after being presented with virtually unlimited training data, we looked into areas in chemistry where similar situations could be achieved. Encountering large amounts of training data in chemistry is still rare, so we turned to two areas where realistic training data can be fabricated in large quantities, namely a) the recognition of machine-readable structures from images of chemical diagrams and b) the conversion of IUPAC(-like) names into structures and vice versa. In this talk, we outline the challenges, technical implementation and results of this study.
Optical Chemical Structure Recognition (OCSR): Vast amounts of chemical information remain hidden in the primary literature and have yet to be curated into open-access databases. To automate the process of extracting chemical structures from scientific papers, we developed the DECIMER.ai project. This open-source platform provides an integrated solution for identifying, segmenting, and recognising chemical structure depictions in scientific literature. DECIMER.ai comprises three main components: DECIMER-Segmentation, which utilises a Mask-RCNN model to detect and segment images of chemical structure depictions; DECIMER-Image Classifier EfficientNet-based classification model identifies which images contain chemical structures and DECIMER-Image Transformer which acts as an OCSR engine which combines an encoder-decoder model to convert the segmented chemical structure images into machine-readable formats, like the SMILES string.
DECIMER.ai is data-driven, relying solely on the training data to make accurate predictions without hand-coded rules or assumptions. The latest model was trained with 127 million structures and 483 million depictions (4 different per structure) on Google TPU-V4 VMs
Name to Structure Conversion: The conversion of structures to IUPAC(-like) or systematic names has been solved algorithmically or rule-based in satisfying ways. This fact, on the other side, provided us with an opportunity to generate a name-structure training pair at a very large scale to train a proof-of-concept transformer network and evaluate its performance.
In this work, the largest model was trained using almost one billion SMILES strings. The Lexichem software utility from OpenEye was employed to generate the IUPAC names used in the training process. STOUT V2 was trained on Google TPU-V4 VMs. The model's accuracy was validated through one-to-one string matching, BLEU scores, and Tanimoto similarity calculations. To further verify the model's reliability, every IUPAC name generated by STOUT V2 was analysed for accuracy and retranslated using OPSIN, a widely used open-source software for converting IUPAC names to SMILES. This additional validation step confirmed the high fidelity of STOUT V2's translations.
An automated pipeline for comprehensive calculation of intermolecular interaction energies based on molecular force-fields using the Tinker molecular modelling package is presented. Starting with non-optimized chemically intuitive monomer structures, the pipeline allows the approximation of global minimum energy monomers and dimers, configuration sampling for various monomer-monomer distances, estimation of coordination numbers by molecular dynamics simulations, and the evaluation of differential pair interaction energies. The latter are used to derive Flory-Huggins parameters and isotropic particle-particle repulsions for Dissipative Particle Dynamics (DPD). The computational results for force fields MM3, MMFF94, OPLSAA and AMOEBA09 are analyzed with Density Functional Theory (DFT) calculations and DPD simulations for a mixture of the non-ionic polyoxyethylene alkyl ether surfactant C10E4 with water to demonstrate the usefulness of the approach.
Purpose
Although courage has generally been understood as a powerful virtue, research to establish it as a psychological construct is in its infancy. We examined courage in organizations against the backdrop of positive psychology with a design in the Grounded Theory tradition that connects Positive Organizational Behavior and Positive Organizational Scholarship.
Method
The sample consists of organizations that define courage in their mission statement and organizations without such a definition. It includes employees and executives, exploring workplace courage on the macro as well as the micro level. Eleven organizations and 23 participants contributed to the interview study.
Results
Applying Glaser's theoretical coding, specifically the C-family, we propose that courage arises from a decisional conflict in three major domains: the self, social interaction, and performance. It is located on a continuum between apathy and foolhardiness and can take on reactive, proactive, or autonomous forms. Whether and to what extent courage manifests, is a dynamic process contingent upon organizational structure, culture, and communication climate as well as individual cognitiveaffective personality systems.
Limitations
The model depicts the complexity of the phenomenon, rather than details of its individual components. It goes beyond pre-defined categories and prevailing definitions.
Implications
Modern organizations are characterized by volatility, uncertainty, complexity, and ambiguity (VUCA).
Courage is crucial in such an environment and can be systematically fostered across the whole human
resource management cycle.
Value
The study advances theory building on courage in the workplace and highlights its potential to be
measured, developed and managed for more effective work performance.
Adhesive organs enable insects to reversibly adhere to substrates even during rapid locomotion. In this process a very fast but reliable change of adhesion and detachment is realised. The stick insect Carausius morosus detaches its adhesive organs by peeling them off the substrate, meaning little areas of the adhesive organs are detached one after another. For such a detachment mechanism low pulling forces are needed. A detachment mechanism as peeling seems also for artificial adhesion devices to be the easiest and the most effortless mechanism for detachment. However, artificial adhesion devices mostly exhibit a solid backing layer preventing effortless peeling. To lift up and detach a small area at the corner of an adhesion device the backing layer has to be tilted, resulting in a deformation of the whole adhesion device, which requires high forces. Subdividing the backing layer into small subunits allows a detachment of a small area at the corner of the adhesion device without deforming the rest of the adhesion device. Thereby, less force is needed to initiate and to complete detachment. To realise an easy detachment of artificial adhesion devices we constructed a holder, which gradually detaches an adhesion device from two sides off the substrate. During normal loading the subunits of the holder interlock with each other so that the pulling force is equally distributed over the whole contact area of the adhesion device ensuring maximal adhesion force. In addition, the holder can be used to increase adhesion during application of the adhesion device. When brought into contact with the substrate with lifted sides, which are lowered subsequently, air trapping is prevented and hence the area of contact can be maximised.