HFTor - HfT Open Repository (Hochschule für Technik Stuttgart)
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District heating in the future - thoughts on the business model
No full textIn this study, we apply a combination of methods for understanding how business models need to change to meet changing business conditions in the future (time horizon 2050). The process of applying the value proposition canvas and the business model canvas for understanding the future business models to the case of district heating has been documented. The energy transition necessitates a combination of new and existing solutions. District heating is one existing and enabling technology. The sector is, however, facing several challenges that will impact the way that business must be conducted in the future. We provide new knowledge about the characteristics of the future district heating business model and illustrate that technical development must be accompanied by business development otherwise the competitiveness of new technology is reduced. Main results show that a high level of digitalisation, enabling customers to make choices that are efficient to the district heating system, is a key future feature. Additionally, co-creation with a small group of dedicated customers will drive the sector's ongoing development. The results from the study are replicable and of relevance to other sectors undergoing large change
RFID in complex production and logistics processes in the automotive industry.
No full textRFID (Radio Frequency Identification) is used in production and logistics in the automotive industry to automate and optimise processes, as RFID has some advantages over barcodes, e.g., no line of sight is needed and RFID transponders can be read in a bulk. When introducing a new RFID application into a company, a pilot is usually carried out first, to test the feasibility. If the pilot is successful, the application is then transferred to series operation in a production area. If the series operation of the RFID application works reliably, the RFID application is rolled out in other production areas, halls, and plants, so that they can also benefit from the advantages of RFID, such as time savings in newly automated processes.
However, the rollout and operation of RFID applications pose major challenges. During rollout, for example, the antennas of an RFID gate must be aligned in the best possible way because the positioning and orientation between RFID transponders and antennas influence the detection rate. Due to the many possible mounting heights and angles of the antennas of an RFID gate, their optimal alignment is a major challenge. Currently, the most common methods for doing so are exemplary guidelines based on expert knowledge and the trial-and-error principle, but so far no algorithm has been published that systematically determines the optimal antenna orientation to increase the detection rate, to the best of the author’s knowledge. Therefore, in this work, a new algorithm for optimal antenna alignment was
developed and tested with the objective of improving the detection rate compared to the approach based on expert knowledge and the trial-and-error principle.
During a rollout, the RFID installation is set up and put into operation in a new environment. The different environmental influences lead to different sources of interference, which have a negative effect on the detection rate. Due to the lack of application experience, it is a challenge to systematically identify and reduce these sources of interference, because there are no test procedures or guidelines for this activity. Therefore, in this work, a new test procedure was developed for the identification and reduction of sources of interference. The verification shows that the application of this test procedure eliminated all simulated sources of interference and thus significantly improved the performance, such as the detection rate.
During operation, the data generated by RFID installations are not used for further analyses and insights to optimise material flow, which could help to solve a common and often reiterated problem, the low-cost efficiency of RFID. Therefore, a model for a digital twin of the RFID-enabled material flow in real time was developed in this work, and then implemented in a practical case study to prove its feasibility. A simulative profitability analysis shows the potential cost savings through this digital twin. An additional user survey confirms that the digital twin of the RFID-enabled material flow in real time could be very helpful and needed to optimise the material flow
Impact Sound from Balconies in Buildings
No full textWith the increasing urban densification, balconies are gaining in popularity as they improve the living quality in homes. Thermal insulation between balconies and the building’s façade is currently state of the art in Germany. The most popular balcony construction is a reinforced concrete balcony, separated from the building by a thermal insulation element (TIE), to reduce the thermal energy losses. The impact sound transmission from balconies, however, is a topic that has not been properly addressed to date. Within this research project, laboratory and in-situ measurements were performed to investigate the impact sound transmission from balconies. Firstly, this paper will focus on measurement results in buildings comparing the levels of direct and flanking impact sound transmission. Secondly, frequency dependent and single number value predictions were performed for the building situations in accordance to current and planned national and international standards such as EN 12354-2 and are compared to the measurement result
Wastewater pipes as structure-borne sound sources: Laboratory measuerements and finite element analysis
No full textThe noise emitted by waste water pipes is, in most cases, generated by structure- borne sound transmission. The water flowing through the pipe causes a vibration of the pipe system that is transmitted to the installation wall through pipe clamps. Laboratory measurements and finite element simulations of a waste water pipe, excited by an electrodynamic shaker (to simplify the real excitation by water), were used to characterize it as a structure-borne sound source by its blocked force, free velocity and mobility. The characterization is carried out 1.) on the freely suspended pipe and 2.) in-situ with the pipe installed on a reception plate according to EN 15657. The overall aim of this study is to provide source data for waste water pipes that can be used for the prediction of the sound transmission in buildings using EN 12354-5 with respect to the recently revised EN 14366-1 that is currently being used for the characterization of wastewater pipes
Is the uncertain self good at detecting lies? The influence of personal uncertainty on deception detection
No full textFive experiments (total number of judging participants = 1309, four different kinds of stimulus materials with a total of 464 messages, total number of judgements = 19,634) investigated the influence of personal uncertainty on the process of lie detection in social relationships. Building on and extending basic assumptions of uncertainty management models, we reasoned that uncertainty about themselves motivates people to evaluate the quality of their relationships. A crucial aspect of the quality of relationships with other people is the truthfulness with which they communicate verbally with you and anyone else. We proposed that if these assumptions are valid, reminding people of their personal uncertainties should lead them to use valid verbal cues in veracity judgements more. This enhanced usage of valid verbal cues should result in better accuracy in deception detection. An internal meta-analysis of the five experiments reveals only a small, not significant, overall effect of uncertainty salience on detection accuracy with larger effect sizes for experiments conducted in the laboratory than for those conducted online. Hence, if personal uncertainty plays a role in the process of deception detection, it seems to be subject to moderators such as methodological or motivational factors
A QGIS plugin for gully erosion modeling
No full textGully erosion affects the landscape and human life in many ways, including the destruction of agricultural land and infrastructures, altering the hydraulic potential of soils, as well as water availability. Due to climate change, more areas are expected to be affected by gully erosion in the future, threatening especially low-income agricultural regions. In the past decades, quantitative methods have been proposed to simulate and predict gully erosion at different scales. However, gully erosion is still underrepresented in modern GIS-based modeling and simulation approaches. Therefore, this study aims to develop a QGIS plugin using Python to assess gully erosion dynamics. We explain the preparation of the input data, the modeling procedure based on Sidorchuk’s (Sidorchuk A (1999) Dynamic and static models of gully erosion. CATENA 37:401–414.) gully simulation model, and perform a detailed sensitivity analysis of model parameters. The plugin uses topographical data, soil characteristics and discharge information as gully model input. The plugin was tested on a gully network in KwaThunzi, KwaZulu-Natal, South Africa. The results and sensitivity analyses confirm Sidorchuck’s earlier observations that the critical runoff velocity is a main controlling parameter in gully erosion evolution, alongside with the slope stability threshold and the soil erodibility coefficient. The implemented QGIS plugin simplifies the gully model setup, the input parameter preparation as well as the post-processing and visualization of modelling results. The results are provided in different data formats to be visualized with different 3D visualization software tools. This enables a comprehensive gully assessment and the derivation of respective coping and mitigation strategies