The 10 most recently published documents
Carbon fiber-epoxy laminates are used in aerospace manufacturing, e.g. as substrates for solar cells of satellites. Commonly, fibers or fibermats are impregnated with epoxy resin and placed in the required orientation. During subsequent curing, the resin molecules are crosslinked. Cured parts are characterized by their glass transition temperature (Tg). It has been observed that Tg of epoxy matrix resin vary with recorded absolute air humidity during wet fiber placement manufacturing. Based on the production data of a series production of 203 carbon fiber laminates for space application, an empirical linear relationship between the absolute air humidity at the beginning of each production day and the observed glass transition temperature of the fully cured laminate is formulated and validated. The empirical equation describes a linear decrease of achievable glass transition temperature with increasing absolute air humidity. The quantitative nature of the results encourages straightforward practical application to determine the maximum achievable Tg for given production conditions.
Battery power is crucial for wearable devices as it ensures continuous operation, which is critical for real-time health monitoring and emergency alerts. One solution for long-lasting monitoring is energy harvesting systems. Ensuring a consistent energy supply from variable sources for reliable device performance is a major challenge. Additionally, integrating energy harvesting components without compromising the wearability, comfort, and esthetic design of healthcare devices presents a significant bottleneck. Here, we show that with a meticulous design using small and highly efficient photovoltaic (PV) panels, compact thermoelectric (TEG) modules, and two ultra-low-power BQ25504 DC-DC boost converters, the battery life can increase from 9.31 h to over 18 h. The parallel connection of boost converters at two points of the output allows both energy sources to individually achieve maximum power point tracking (MPPT) during battery charging. We found that under specific conditions such as facing the sun for more than two hours, the device became self-powered. Our results demonstrate the long-term and stable performance of the sensor node with an efficiency of 96%. Given the high-power density of solar cells outdoors, a combination of PV and TEG energy can harvest energy quickly and sufficiently from sunlight and body heat. The small form factor of the harvesting system and the environmental conditions of particular occupations such as the oil and gas industry make it suitable for health monitoring wearables worn on the head, face, or wrist region, targeting outdoor workers.
Autonomous navigation on inland waters requires an accurate understanding of the environment in order to react to possible obstacles. Deep learning is a promising technique to detect obstacles robustly. However, supervised deep learning models require large data-sets to adjust their weights and to generalize to unseen data. Therefore, we equipped our research vessel with a laser scanner and a stereo camera to record a novel obstacle detection data-set for inland waters. We annotated 1974 stereo images and lidar point clouds with 3d bounding boxes. Furthermore, we provide an initial approach and a suitable metric to compare the results on the test data-set. The data-set is publicly available and seeks to make a contribution towards increasing the safety on inland waters.
Given the increasing demand for application development and process automation, Low-Code Development Platforms (LCDPs) have become highly relevant in recent years. However, the lack of familiarity with the implementation and application of LCDP in organizations poses a challenge. This publication therefore aims to shed light on the essential organizational capabilities that companies must master to overcome this obstacle. Using action design research, this study develops a model-based framework of 21 organizational capabilities for successful LCDP adoption. It underscores the importance of conceptual development as a prerequisite for effective management and long-term application of the technology. Furthermore, it emphasizes the importance of considering both technical and social aspects of the LCDP information system. The findings contribute to academia by providing a model-based capability framework, which serves as a structure for driving future research. Moreover, practitioners benefit from a practice-oriented and evaluated summary of initialization tasks and capabilities required for successful adoption.
Digital transformation urges organizations to strategically invest in information technology (IT) to keep up with the competition. The responsible strive to choose the right digital initiatives that can maximize the benefit. Thereby, they still struggle to communicate IT costs and demonstrate the business value of IT. The goal of this paper is to get a deeper understanding of the perception of IT costs and business value and support their effective communication. Applying the focus group method, we analyzed in four interview sessions that stakeholders perceive IT costs and business value differently and that a common perception serves as the basis of communication. We then identified and evaluated 20 success factors to establish effective communication of IT costs and IT business value. Hence, this paper enables a better understanding of the perception and the operationalization of effective communication mainly between business and IT executives regarding IT costs and IT business value.
Digitalization requires organizations to strategically invest in information technology (IT). As a result, the costs associated with IT in companies are rising and technological progress changes the setting for IT management. This poses challenges for IT managers to ensure spend-efficiency and manage IT costs transparently. However, no current literature review gives an overview of how IT cost management (ITCM) research dealt with past transformations. This paper aims to investigate ITCM concepts considering their historical context. It then derives implications for the digital age and identifies future research fields. The historical literature review reveals that ITCM research evolved with technological advances and the target to manage all IT-related costs and evaluate the impact of IT spend. However, the presented concepts lack consideration of current changes that hamper spend-efficiency and strategic decisions. Hence, this paper enables future research to address the identified research gaps. Additionally, practitioners gain awareness of how they can benefit from developed ITCM concepts.
