Coding by Design: GPT-4 empowers Agile Model Driven Development

Generating code from a natural language using Large Language Models (LLMs) such as ChatGPT, seems groundbreaking. Yet, with more extensive use, it's evident that this approach has its own limitations. The inherent ambiguity of natural language presents challenges for complex software designs. Accordingly, our research offers an Agile Model-Driven Development (MDD) approach that enhances code auto-generation using OpenAI's GPT-4. Our work emphasizes "Agility" as a significant contribution to the current MDD method, particularly when the model undergoes changes or needs deployment in a different programming language. Thus, we present a case-study showcasing a multi-agent simulation system of an Unmanned Vehicle Fleet. In the first and second layer of our approach, we constructed a textual representation of the case-study using Unified Model Language (UML) diagrams. In the next layer, we introduced two sets of constraints that minimize model ambiguity. Object Constraints Language (OCL) is applied to fine-tune the code constructions details, while FIPA ontology is used to shape communication semantics and protocols. Ultimately, leveraging GPT-4, our last layer auto-generates code in both Java and Python. The Java code is deployed within the JADE framework, while the Python code is deployed in PADE framework. Concluding our research, we engaged in a comprehensive evaluation of the generated code. From a behavioural standpoint, the auto-generated code aligned perfectly with the expected UML sequence diagram. Structurally, we compared the complexity of code derived from UML diagrams constrained solely by OCL to that influenced by both OCL and FIPA-ontology. Results indicate that ontology-constrained model produce inherently more intricate code, but it remains manageable and low-risk for further testing and maintenance

Hydrodynamic Investigations of Rapidly Stretched Liquid Bridges

Liquid bridges have become an integral part of many industrial processes relevant to consumer production. For example, the coating technology often includes dip-coating, printing, or spraying of liquid materials. Liquid bridge or liquid jet fast stretching is an essential element of such processes. Bridge stretching determines the outcome of liquid atomization and the agglomeration of wet particles. Moreover, liquid bridge stretching is used for the rheological characterization of complex liquids. This thesis deals with the investigation of fast stretched Newtonian fluid bridges. The unique feature of this study is the investigation of particularly high stretching rates for very small liquid bridge heights. A system consisting of two parallel substrates was developed. One substrate can be moved with a constant, controllable acceleration while the other substrate remains stationary. It allows performing parameter studies with accelerations of up to 180 m/s2 and initial bridge heights starting from 50 μm. Extensive experimental and theoretical studies were carried out to identify the most influencing parameters and, therefore, to understand the physical mechanisms of the observed phenomena better. The characterization includes a description of the kinematics of the liquid bridge stretching and different outcomes like liquid cavitation, finger formation during stretching, and bridge pinch-off. The evolution of the main geometrical properties of the stretching liquid bridge is characterized. These properties include the curvature and shape of the meniscus, length, and diameter of the liquid bridge. Two main regimes of a fast stretching are identified: viscous regime, determined by the Reynolds number, and capillary regime for low viscosity liquids, governed by the Weber number. The knowledge of the kinematics of the bridge allows us to determine the appropriate scales for a description of the stretching outcomes. The cavitation phenomena are described using the estimation of the distribution of the viscous pressure in the gap. This pressure determines the evolution of the cavity radius. A bubble growth model has been developed, which allows the prediction of the instant of the maximum bubble diameter as a function of the cavitation inception rather well. Next, the stability analysis of the bridge free interface is performed, which accounts for the viscous effects and inertia. The predicted condition for the appearance of the fingers and the number of these fingers agree well with the experimental data. Finally, the model for the pinch-off time of the stretching bridge is developed. The scales for the pinch-off time have been determined for viscous and for the capillary stretching regimes. The experimental and theoretical results can be potentially useful for optimizing the operational conditions during printing and modeling atomization, accretion, and agglomeration phenomena

Dewetting behaviour of liquid bridges stretched by an accelerated plate

Liquid bridge stretching is of interest for a wide field of industrial applications like printing and coating, but also for the functioning of aircraft engines because of its importance in the process of ice crystal icing. In the present experimental study, the focus lies on describing the geometry of the liquid bridge during the stretching process with respect to midpoint diameter, contact line diameter and contact angle for constant accelerations from 10m/s 2 up to 180m/s 2 . The observed evolution of the dynamic contact angle is described as a function of the capillary number. For the early phase of the stretching process relations for the curvature and midpoint diameter are proposed

Dewetting behaviour of liquid bridges stretched by an accelerated plate

Liquid bridge stretching is of interest for a wide field of industrial applications like printing and coating, but also for the functioning of aircraft engines because of its importance in the process of ice crystal icing. In the present experimental study, the focus lies on describing the geometry of the liquid bridge during the stretching process with respect to midpoint diameter, contact line diameter and contact angle for constant accelerations from 10m/s 2 up to 180m/s 2 . The observed evolution of the dynamic contact angle is described as a function of the capillary number. For the early phase of the stretching process relations for the curvature and midpoint diameter are proposed

Three-Dimensional Urban Path Planning for Aerial Vehicles Regarding Many Objectives

Planning flight paths for unmanned aerial vehicles in urban areas requires consideration of safety, legal, and economic aspects as well as attention to social factors for gaining public acceptance. To solve this many-objective path planning problem in the three-dimensional space, we propose a hybrid framework combining an exact Dijkstra search and a metaheuristic evolutionary optimization. Given a start and an endpoint, we optimize a path regarding the risk in case of a system failure, the radio signal disturbance between the aerial vehicle and a ground station, the energy consumption, and the noise immission on city residents. The optimization includes constraints for static obstacle collision avoidance and compliance with the minimum flight altitude. The result is a set of smooth and three-dimensional paths that realize different trade-offs between the defined objectives. As an example, we consider an urban transportation application for aerial vehicles in San Francisco. For all tests, we use real-world data from OpenStreetMap. In a statistical evaluation, we test the efficiency of our framework against different state-of-the-art optimizers. Moreover, we extend the framework with two features that allow the user to integrate arbitrary objectives and unknown scenarios into the path planning framework