Open Access

The EXPLAIN project (EXPLanatory interactive Artificial intelligence for INdustry) aims at enabling explainable Machine Learning in industry. MLOps (Machine Learning Operations) includes tools, practices, and processes for deploying ML (Machine Learning) in production. These will be extended by explainability methods as part of the project. This study aims to determine to what extent MLOps is implemented by four project partner companies. Further, the study describes the ML use cases, MLOps software architecture, tools, and requirements in the companies perspective. Besides, requirements for a novel MLOps software architecture, including explainability methods, are collected. As a result the interviews show that each of the interviewed industry partners use MLOps differently. Different tools and architectural patterns are used depending on the particular use case. Overall, most information we gathered focused on architecture decisions in the MLOps tool landscape used by the interviewed companies.

The University of Hildesheim owns many different software systems for teaching. So far, no one has attempted to cover all systems and create an architectural description of e-learning at the University of Hildesheim. This report describes the applications relevant to education. These include software developed by the university, third-party tools provided by the university, cloud tools closely associated with the university, and tools provided by the university under contract. Implemented functionalities are explored, and functional specifcations are described, including information about technical and operational requirements. Here, the software is primarily teaching tools. However, the report does not include software and development environments in which students are taught but rather tools that apply to teaching. The variety of tools in different courses makes it impossible to cover all the applications that are used by work groups or individuals. The main goal of this investigation is to capture the university's e-learning state and describe the architecture - mainly to ease the development of applications for developers. Further objectives are to identify new ideas and summarize current goals. We conducted surveys of the teaching staff to determine the current status. Transcripts of interviews, tables provided by interviewed persons, and websites were used as references to prepare this document. We hope that future investigations will provide updates on current information and add information in this context.

Road accidents are one of the leading causes of death worldwide, particularly among young people. The police and local authorities therefore strive to reduce the risk of accidents through appropriate road safety measures. In order to plan these measures, the relevant types of accidents, i. e., accidents with certain features, must first be recognized. However, the variety of accident features and the amount of resulting feature combinations make it impossible to monitor all accident types manually. In this thesis, methods are proposed to automatically identify interesting accident types. Here, it is investigated whether combinations of features occur together and how the temporal pattern of the combined occurrence behaves. The change mining approach can then be used to determine whether structural changes in frequency occur during the period under consideration. For example, a feature combination that suddenly appears more frequently or exhibits a change in seasonality should be prioritized for further investigation so that appropriate road safety measures may be initiated for that combination. The implemented strategic, multi-stage data mining framework based on frequent itemset mining, time series clustering, forecasting methods, and a scoring process is able to detect interesting feature combinations. These are then processed on a map in a web interface suitable for the respective audience in order to support the strategic planning of road safety measures. The framework is applied to several accident data sets from different countries to determine suitable default parameter values for the respective data analysis methods and to carefully align the methods. It is shown that there exist only minor dependencies of the parameter selection on the database to be analyzed. For operational planning, it is necessary to consider small geographic areas and identify the features that have the greatest impact on accident occurrence there. Therefore, the developed operational framework analyzes and predicts the course of accident time series, taking into account the associated feature-specific time series. On the one hand, this makes it possible to increase the forecast performance, and, on the other hand, to determine which accident features have a significant influence on the course of the accident numbers over time. The insights gained can be used as a basis for short-term measures.

Recent decades have seen exponential growth in data acquisition attributed to advancements in edge device technology. Factory controllers, smart home appliances, mobile devices, medical equipment, and automotive sensors are a few examples of edge devices capable of collecting data. Traditionally, these devices are limited to data collection and transfer functionalities, whereas decision-making capabilities were missing. However, with the advancement in microcontroller and processor technologies, edge devices can perform complex tasks. As a result, it provides avenues for pushing training machine learning models to the edge devices, also known as learning-at-the-edge. Furthermore, these devices operate in a distributed environment that is constrained by high latency, slow connectivity, privacy, and sometimes time-critical applications. The traditional distributed machine learning methods are designed to operate in a centralized manner, assuming data is stored on cloud storage. The operating environment of edge devices is impractical for transferring data to cloud storage, rendering centralized approaches impractical for training machine learning models on edge devices. Decentralized Machine Learning techniques are designed to enable learning-at-the-edge without requiring data to leave the edge device. The main principle in decentralized learning is to build consensus on a global model among distributed devices while keeping the communication requirements as low as possible. The consensus-building process requires averaging local models to reach a global model agreed upon by all workers. The exact averaging schemes are efficient in quickly reaching global consensus but are communication inefficient. Decentralized approaches employ in-exact averaging schemes that generally reduce communication by communicating in the immediate neighborhood. However, in-exact averaging introduces variance in each worker's local values, requiring extra iterations to reach a global solution. This thesis addresses the problem of learning-at-the-edge devices, which is generally referred to as decentralized machine learning or Edge Machine Learning. More specifically, we will focus on the Decentralized Parallel Stochastic Gradient Descent (DPSGD) learning algorithm, which can be formulated as a consensus-building process among distributed workers or fast linear iteration for decentralized model averaging. The consensus-building process in decentralized learning depends on the efficacy of in-exact averaging schemes, which have two main factors, i.e., convergence time and communication. Therefore, a good solution should keep communication as low as possible without sacrificing convergence time. An in-exact averaging solution consists of a connectivity structure (topology) between workers and weightage for each link. We formulate an optimization problem with the objective of finding an in-exact averaging solution that can achieve fast consensus (convergence time) among distributed workers keeping the communication cost low. Since direct optimization of the objective function is infeasible, a local search algorithm guided by the objective function is proposed. Extensive empirical evaluations on image classification tasks show that the in-exact averaging solutions constructed through the proposed method outperform state-of-the-art solutions. Next, we investigate the problem of learning in a decentralized network of edge devices, where a subset of devices are close to each other in that subset but further apart from other devices not in the subset. Closeness specifically refers to geographical proximity or fast communication links. We proposed a hierarchical two-layer sparse communication topology that localizes dense communication among a subgroup of workers and builds consensus through a sparse inter-subgroup communication scheme. We also provide empirical evidence of the proposed solution scaling better on Machine Learning tasks than competing methods. Finally, we address scalability issues of a pairwise ranking algorithm that forms an important class of problem in online recommender systems. The existing solutions based on a parallel stochastic gradient descent algorithm define a static model parameter partitioning scheme, creating an imbalance of work distribution among distributed workers. We propose a dynamic block partitioning and exchange strategy for the model parameters resulting in work balance among distributed workers. Empirical evidence on publicly available benchmark datasets indicates that the proposed method scales better than the static block-based methods and outperforms competing state-of-the-art methods.

Finding an available parking spot in city centers can be a cumbersome task for individual drivers and also negatively affects general traffic flow and CO2 emissions. In the context of smart cities and the internet of things this problem can be mitigated by using available data to monitor and predict parking occupancy in order to guide users to an available parking location near their destination. With this goal in mind there arise multiple challenges of which we introduce selected ones to propose novel solutions based on machine learning. The focus of this work is to enable the usage of readily available and inexpensive data sources like parking meter transactions, opposed to expensive technology like in-ground sensors or cameras where the costs prevent a widespread coverage. Our proposed data sources do not directly monitor the actual parking availability but still provide enough signal for our algorithms to infer the real parking situation with high accuracy. As part of this work we developed a parking availability prediction system based on parking meter transactions that was deployed to 33 german cities. A main contribution of our work is the proposal of a novel way to generate labels based on the parking transactions and to use semi-supervised-, more specifically positive-unlabeled learning, to leverage the sparse signal in order to require as little data as possible. Additionally, we utilize and design novel methodologies in the area of transfer learning to learn simultaneously from different cities which leads to the previously seldom explored setting of combining transfer learning with positive-unlabeled learning. We therefore introduce a novel algorithm to tackle this problem type. We hope that our work enables the deployment of smart parking systems at lower costs and therefore leads towards the goal of smart parking guidance in smart cities.