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While the contribution of renewable energy technologies to the energy system is increasing, so is its level of complexity. In addition to new types of consumer systems, the future system will be characterized by volatile generation plants that will require storage technologies. Furthermore, a solid interconnected system that enables the transit of electrical energy can reduce the need for generation and storage systems. Therefore, appropriate methods are needed to analyze energy production and consumption interactions within different system constellations. Energy system models can help to understand and build these future energy systems. However, although various energy models already exist, none of them can cover all issues related to integrating renewable energy systems. The existing research gap is also reflected in the fact that current models cannot model the entire energy system for very high shares of renewable energies with high temporal resolution (15 min or 1-h steps) and high spatial resolution. Additionally, the low availability of open-source energy models leads to a lack of transparency about exactly how they work. To close this gap, the sector-coupled energy model (UCB-SEnMod) was developed. Its unique features are the modular structure, high flexibility, and applicability, enabling it to model any system constellation and can be easily extended with new functions due to its software design. Due to the software architecture, it is possible to map individual buildings or companies and regions, or even countries. In addition, we plan to make the energy model UCB-SEnMod available as an open-source framework to enable users to understand the functionality and configuration options more easily. This paper presents the methodology of the UCB-SEnMod model. The main components of the model are described in detail, i.e., the energy generation systems, the consumption components in the electricity, heat, and transport sectors, and the possibilities of load balancing.
The purpose of this article is to evaluate optimal expected utility risk measures (OEU) in a risk-constrained portfolio optimization context where the expected portfolio return is maximized. We compare the portfolio optimization with OEU constraint to a portfolio selection model using value at risk as constraint. The former is a coherent risk measure for utility functions with constant relative risk aversion and allows individual specifications to the investor’s risk attitude and time preference. In a case study with three indices, we investigate how these theoretical differences influence the performance of the portfolio selection strategies. A copula approach with univariate ARMA-GARCH models is used in a rolling forecast to simulate monthly future returns and calculate the derived measures for the optimization. The results of this study illustrate that both optimization strategies perform considerably better than an equally weighted portfolio and a buy and hold portfolio. Moreover, our results illustrate that portfolio optimization with OEU constraint experiences individualized effects, e.g., less risk-averse investors lose more portfolio value in the financial crises but outperform their more risk-averse counterparts in bull markets.
Die umlagefinanzierte gesetzliche Rentenversicherung kann angesichts der demografischen Entwicklung eine auskömmliche Versorgung im Alter bald nicht mehr sichern. Indem die Bürger:innen über eine kapitalgedeckte Alterssicherung am Unternehmensvermögen mittelbar beteiligt werden, könnte die Rentenlücke zumindest teilweise geschlossen werden. Das Unternehmensvermögen sollte bei einem neuen Reformanlauf auch vollständig in die Erbschaftsteuer einbezogen werden; dabei darf aber der Fortbestand der Unternehmen nicht gefährdet werden. Die Erbschaftsteuer auf Unternehmensvermögen könnte dabei als Finanzierungsquelle für eine kapitalgedeckte Altersgrundsicherung dienen.
In the single-processor scheduling problem with time restrictions there is one main processor and B resources that are used to execute the jobs. A perfect schedule has no idle times or gaps on the main processor and the makespan is therefore equal to the sum of the processing times. In general, more resources result in smaller makespans, and as it is in practical applications often more economic not to mobilize resources that will be unnecessary and expensive, we investigate in this paper the problem to find the smallest number B of resources that make a perfect schedule possible. We show that the decision version of this problem is NP-complete, derive new structural properties of perfect schedules, and we describe a Mixed Integer Linear Programming (MIP) formulation to solve the problem. A large number of computational tests show that (for our randomly chosen problem instances) only B=3 or B=4 resources are sufficient for a perfect schedule.
Decoding the cellular network interaction of neurons and glial cells are important in the development of new therapies for diseases of the central nervous system (CNS). Electrophysiological in vivo studies in mice will help to understand the highly complex network. In this paper, the optimization of epidural liquid crystal polymer (LCP) electrodes for different platinum electroplating parameters are presented and compared. Constant current and pulsed current electroplating varied in strength and duration was used to decrease the electrode impedance and to increase the charge storage capacity (CSCc). In best cases, both methods generated similar results with an impedance reduction of about 99%. However, electroplating with pulsed currents was less parameter-dependent than the electroplating with constant current. The use of ultrasound was essential to generate platinum coatings without plating defects. Electrode model parameters extracted from the electrode impedance reflected the increase in surface porosity due to the electroplating processes.
Intervention in the form of core-specific stability exercises is evident to improve trunk stability. The purpose was to assess the effect of an additional 6 weeks sensorimotor or resistance training on maximum isokinetic trunk strength and response to sudden dynamic trunk loading (STL) in highly trained adolescent athletes. The study was conducted as a single-blind, 3-armed randomized controlled trial. Twenty-four adolescent athletes (14f/10 m, 16 ± 1 yrs.;178 ± 10 cm; 67 ± 11 kg; training sessions/week 15±5; training h/week 22±8) were randomized into resistance training (RT; n=7), sensorimotor training (SMT; n = 10), and control group (CG; n = 7). Athletes were instructed to perform standardized, center-based training for 6 weeks, two times per week, with a duration of 1 h each session. SMT consisted of four different core-specific sensorimotor exercises using instable surfaces. RT consisted of four trunk strength exercises using strength training machines, as well as an isokinetic dynamometer. All participants in the CG received an unspecific heart frequency controlled, ergometer-based endurance training (50 min at max. heart frequency of 130HF). For each athlete, each training session was documented in an individual training diary (e.g., level of SMT exercise; 1RM for strength exercise, pain). At baseline (M1) and after 6 weeks of intervention (M2), participants’ maximum strength in trunk rotation (ROM:63°) and flexion/extension (ROM:55°) was tested on an isokinetic dynamometer (concentric/eccentric 30°/s). STL was assessed in eccentric (30°/s) mode with additional dynamometer-induced perturbation as a marker of core stability. Peak torque [Nm] was calculated as the main outcome. The primary outcome measurements (trunk rotation/extension peak torque: con, ecc, STL) were statistically analyzed by means of the two-factor repeated measures analysis of variance (α = 0.05). Out of 12 possible sessions, athletes participated between 8 and 9 sessions (SMT: 9 ± 3; RT: 8 ± 3; CG: 8 ± 4). Regarding main outcomes of trunk performance, experimental groups showed no significant pre–post difference for maximum trunk strength testing as well as for perturbation compensation (p > 0.05). It is concluded, that future interventions should exceed 6 weeks duration with at least 2 sessions per week to induce enhanced trunk strength or compensatory response to sudden, high-intensity trunk loading in already highly trained adolescent athletes, regardless of training regime.
In this paper, the mechanical damage behavior is investigated based on the characteristic roughness on the surface and the orientation of superficial structures. The main goal is to explore the surface roughness on mechanically loaded copper conductors as a lifetime indicator. For this purpose, copper conductors are mechanically stressed in accordance with EN 50,396 and then examined metallographically and microscopically. The microstructure examination shows that the roughness is caused by material extrusion and cracks due to work hardening in the surface area. Using confocal microscopy, it is shown for the first time that significant formation of surface roughness takes place over the service life of copper conductors. The roughness increases monotonically, but not linearly with number of cycles, due to internal microstructural processes and can be divided into three sections. First inspections of the conductor surface over lifetime show a correlation between the intensity of structures orientated 45° to the loading direction and the roughness. This phenomenon, already known from microscopic slip lines, is thus also evident in macroscopic roughness formation and is well founded by the research theory on material extrusion along dislocation lines. In summary, a lifetime determination is possible based on its developing roughness which enables the utilization as a sensor element.
Gait analysis is a systematic study of human movement. Combining wearable foot pressure sensors and machine learning (ML) solutions for a high-fidelity body pose tracking from RGB video frames could reveal more insights into gait abnormalities. However, accurate detection of heel strike (HS) and toe-off (TO) events is crucial to compute interpretable gait parameters. In this work, we present an experimental platform to study the timing of gait events using a new wearable foot pressure sensor (ActiSense System, IEE S.A., Luxembourg), and Google’s open-source ML solution MediaPipe Pose. For this purpose, two StereoPi systems were built to capture stereoscopic videos and images in real time. MediaPipe Pose was applied to the synchronized StereoPi cameras, and two algorithms (ALs) were developed to detect HS and TO events for gait and analysis. Preliminary results from a healthy subject walking on a treadmill show a mean relative deviation across all time spans of less than 4% for the ActiSense device and less than 16% for AL2 (33% for AL1) employing MediaPipe Pose on StereoPi videos. Finally, this work offers a platform for the development of sensor- and video-based ALs to automatically identify the timing of gait events in healthy individuals and those with gait disorders.
This paper presents a feasibility study for the production of recycled glycol modified polyethylene terephthalate (PETG) material for additive manufacturing. Past studies showed a variety of results for the recycling of 3D-printing material, therefore the precise effect on the material properties is not completely clear. For this work, PETG waste of the same grade was recycled once and further processed into 3D printing filament. The study compares three blend ratios between purchased plastic pellets and recycled pellets to determine the degradation effect of one recycling cycle and possible blend ratios to counter these effects. Furthermore, the results include a commercially available filament. The comparison uses the filament diameter, the dimensional accuracy of the printed test specimen and mechanical properties as quality criteria. The study shows that the recycled material has a minor decrease concerning the tensile strength and Young’s modulus.
This scientific paper aimed to examine workplace stressors and factors influencing the Work-Life-Balance of nursing staff to understand potential factors and challenges. The Covid-19-pandemic has only again demonstrated the importance of sufficient and well-educated nursing staff. To ensure this, it is also important to consider the well-being of the nurses, because this influences their job performance, the turnover rate and the number of sick employees. To examine the workplace stressors and the Work-Life-Balance of nursing staff, different theoretical approaches and study findings are taken under consideration to determine their influence on the perceived stress of employees in general and nurses in particular and also the importance of a healthy Work-Life-Balance. The study was conducted by the Declaration of Helsinki and Tokyo. Many different factors make the job as a nurse potentially more stressful than for example administrative occupations. Moreover, there are plenty of difficulties for a healthy Work-Life-Balance for nursing staff and also potential negative effects resulting from a poor Work-Life-Balance or a high amount of workplace stressors. It can be concluded that a solution approach for the workplace stressors and a better Work-Life-Balance can only be reached if the employer and the employees work together to decrease the amount of stress, to offer and learn better mechanisms to cope with stress and to incorporate ways to ensure a better Work-Life-Balance.
Objective: In this article, the methods used to simplify the business modelling and founding of new companies are presented and critically reflected. Furthermore, it is discussed to what extent a specific method is advantageous, disadvantageous, applicable, not applicable, or even contradictory.
Methodology: The theoretical analysis is underpinned by a qualitative interview study asking company founders about applying the methods mentioned above. The work is based on scientific papers and books and is complemented by the data originating from a specially designed study.
Findings: The results conclude that business model founding instruments provide strategic guidelines favouring entrepreneurs, yet they turn out to be minor in its real-life significance as numerous factors rooted in different fields of expertise play in.
Value Added: The added value of this paper is in the elaboration of efficiency bringing and risk-minimizing components of the methods, respectively. Accordingly, managers and entrepreneurs of all industries are intended to be equipped with sufficient information content that eases the decision for or against one of the methods as realistic expectations considering the application are likely to emerge.
Recommendations: The limitations of this study are rooted in the chosen qualitative research since every interviewee is a subject to their individual perception.
Purpose: In this article, the canvas used to simplify business modeling of a platform and its visual depiction are put into the entrepreneurial context, and critically reflected accordingly. Furthermore, it is discussed to what extent the canvas is advantageous, disadvantageous, applicable, not applicable, or even contradictory.
Methodology: The analysis is based on theoretical research. Additionally, qualitative interviews with business founders were conducted.
Results: The results conclude that the canvas employed to ease the business model sharpening process supplies founders with essential aspects to cover, yet they are part of a large set of factors that play in.
Conclusion: The limitations of this study are rooted in the chosen research design based on the conceptual review.
The following paper aims to find out consumers' expectations and attitudes towards the innovation "Metaverse". It will also be explored which role the Meta Group plays in mass adaption and how the company influences consumers' possible use and opinion on the project. These results are connected to the fashion industry, further exploring new types of products and a possible distribution channel. Therefore, this study is useful to developers of Metaverses and AR/VR products, the Meta Group, and fashion companies. The main results of this research are: Meta and the Metaverse are seen as critical, the required technology has not yet reached mainstream use, but interest is present. Digital fashion had participants divided, some not willing to spend any money and some already having spent over 100€, although the Metaverse's influence on future purchases is little. The Metaverse could serve as a new distribution channel for clothing products. To conduct this research Google Forms was used. The research is classified as survey-based. The biggest limitation is the nonexistence of the Metaverse as envisioned by Meta, making it hard for participants to answer some of the questions asked.
Global vernetzte Supply Chains (SC) führen bei den Unternehmen zu geringeren Kosten, aber zugleich erhöhen diese auch die Abhängigkeit ggü. den Lieferanten und die Störanfälligkeit der SCs wird erhöht. In den vergangenen Jahren haben zudem die Unsicherheiten für die SCs stark zugenommen. Treiber waren hier u.a. der Brexit, Handelskonflikte oder auch die Corona-Pandemie. In diesem Zusammenhang steht verstärkt die Entwicklung neuer SC-Strategien im Fokus der Unternehmen. Dabei wird stark auf die Verbesserung der Resilienz der SCs geachtet, um dadurch u.a. die Risiken für die SCs zu reduzieren. Die Arbeit beschäftigt sich mit den Auswirkungen steigender Unsicherheiten auf das Design sowie die Resilienz von SCs und hat das Ziel zu ermitteln, ob es Änderungen in der SC bedarf, um auf die Auswirkungen steigender Unsicherheiten zu reagieren und wie die Resilienz zukünftig sichergestellt werden kann (Trade-off zwischen Resilienz und Kosteneffizienz). Im Rahmen der Untersuchung erfolgte eine qualitative Forschung in Form von Experteninterviews, da so u.a. spezifische Meinungen oder auch Begründungen und Einstellungen von bestimmten Personen zu den vorliegenden Thematiken ermittelt werden können. Die Ergebnisse zeigen, dass die Kosten weiterhin meist der entscheidende Aspekt sind und es mehr Transparenz, Flexibilität sowie ein besseres Risikomanagement nötig ist. Des Weiteren bedarf es zukünftig u.a. einer größeren Berücksichtigung von Unsicherheiten, eine Erhöhung von Sicherheitsbeständen sowie eine Verringerung der Komplexität der SCs und u.U. mehr Local Sourcing. Es empfiehlt sich eine weitere Untersuchung hinsichtlich der Kosten, die durch Resilienz-Instrumente sowie durch fehlende Resilienz entstehen können, durchzuführen.
This scientific paper aims to collect and analyze various digital technologies connected to pharmacies and Health 4.0. Thus, the goal is to give basic recommendations for actions for pharmacies to remain successful businesses in the digital future of healthcare. While the total health sector is growing continuously, the total number of pharmacies is shrinking. To be able to face the competitive pressure on the pharmaceutical market, pharmacies have to integrate more efficient digital technologies to be able to increase customers’ experience. Hence, the acceptance and attitude of the German society towards digital health solutions are examined using a short survey and a precise questionnaire. After a detailed analysis of the survey results and the questionnaire answered by a pharmacist, specific digital methods and technologies which make sense for pharmacies can be elaborated. As the future of pharmacies is still quite unexplored, while the health market is shifting to more efficient digital solutions, pharmacies have to adapt to current developments fast. Therefore, this paper can serve as a guideline for pharmacies in the rapid changes toward more digital markets.
Die vorliegende Ausarbeitung beschäftigt sich mit der Frage, ob weibliche Führungskräfte aufgrund spezieller Führungskompetenzen auf den langfristigen Unternehmenserfolg einzahlen. Besondere Beachtung findet hierbei der Faktor der Emotionalen Intelligenz. Nach wie vor ist der Anteil weiblicher Führungskräfte auf deutschen Managementebenen auffallend gering. Um ein Verständnis für die Hintergründe dieser Thematik zu entwickeln, werden zunächst die Ursachen geschlechtsbedingter Differenzierungen erläutert. Die wesentlichen Erkenntnisse entstammen dem Bereich der Geschlechterforschung. Im Anschluss werden diese im Kontext der Führung beleuchtet. Ein besonderes Augenmerk liegt auf der Frage, ob und inwiefern sich ein potentieller weiblicher Führungsstil von der als männlich geltenden Führung unterscheidet. Im weiteren Verlauf des Artikels wird das Phänomen der Emotionalen Intelligenz im Detail betrachtet. Dieses gilt im Kontext der Führung seit geraumer Zeit als Erfolgsfaktor. Ob und inwiefern diese Annahme tatsächlich Bestand hat, soll daher zunächst herausgestellt werden. Abschließend wird geprüft, ob es sich bei der Emotionalen Intelligenz um eine vorwiegend weibliche Kompetenz handelt
This research paper discusses how RFID technology could improve current deposit bottle logistic processes in food retailing and which obstacles impede successful implementations. Research Methodology include desk research: Library, EBSCOhost, wiso.net, Google Scholar, Scientific Journals, Statista, SpringerLink. Implementation of RFID is potentially beneficial, but same obstacles remain outlook. To validate the conclusion further studying and practical proof of concept are necessary. Contributions: supply chain management, return logistics, food retail, beverage industry
In recent years, the retail virtual store has become the main trend in social services. More and more people tend to shop in retail virtual stores. With the development of 3D virtual reality, this trend is getting stronger and stronger. Therefore, the development prospect of virtual retail stores has attracted much attention. This paper examines the impact of companies' and users' popularization of helmet gadgets on in-store traffic and analyzes how virtual reality (VR) could enhance the customer experience throughout the shopping trip. A qualitative research design has been used, which also included conversations with both professionals and consumers. Moreover, this paper seeks to break new ground by attempting to use the current literature to help predict future directions and trends for online shopping.
In this paper two simple synthetic aperture radar (SAR) methods are applied on data from a 24 GHz FMCW radar implemented on a linear drive for educational purposes. The data of near and far range measurements are evaluated using two different SAR signal processing algorithms featuring 2D-FFT and frequency back projection (FBP) method (Moreira et al., 2013). A comparison of these two algorithms is performed concerning runtime, image pixel size, azimuth and range resolution. The far range measurements are executed in a range of 60 to 135 m by monitoring cars in a parking lot. The near range measurement from 0 to 5 m are realised in a measuring chamber equipped with absorber foam and nearly ideal targets like corner reflectors. The comparison of 2D-FFT and FBP algorithm shows that both deliver good and similar results for the far range measurements but the runtime of the FBP algorithm is up to 150 times longer as the 2D-FFT runtime. In the near range measurements the FBP algorithm displays a very good azimuth resolution and targets which are very close to each other can be separated easily. In contrast to that the 2D-FFT algorithm has a lower azimuth resolution in the near range, thus targets which are very close to each other, merge together and cannot be separated.
Background: The STarT-MSK-Tool is an adaptation of the well established STarT-Back-Tool, used to risk-stratify patients with a wider range of musculoskeletal presentations.
Objective: To formally translate and cross-culturally adapt the Keele STarT-MSK risk stratification tool into German (STarT-MSKG) and to establish its reliability and validity.
Methods: A formal, multi-step, forward and backward translation approach was used. To assess validity patients aged ≥18 years, with acute, subacute or chronic musculoskeletal presentations in the lumbar spine, hip, knee, shoulder, or neck were included. The prospective cohort was used with initial data collected electronically at the point-of-consultation. Retest and 6-month follow-up questionnaires were sent by email. Test-retest reliability, construct validity, discriminative ability, predictive ability and floor or ceiling effects were analysed using intraclass correlation coefficient, and comparisons with a reference standard (Orebro-Musculoskeletal-Pain-Questionnaire: OMPQ) using correlations, ROC-curves and regression models.
Results: The participants’ (n = 287) mean age was 47 (SD = 15.8) years, 51% were female, with 48.8% at low, 43.6% at medium, and 7.7% at high risk. With ICC = 0.75 (95% CI 0.69; 0.81) test-retest-reliability was good. Construct validity was good with correlations for the STarT-MSKG-Tool against the OMPQ-Tool of rs = 0.74 (95% CI 0.68, 0.79). The ability of the tool [comparison OMPQ] to predict 6-month pain and disability was acceptable with AUC = 0.77 (95% CI 0.71, 0.83) [OMPQ = 0.74] and 0.76 (95% CI 0.69, 0.82) [OMPQ = 0.72] respectively. However, the explained variance (linear/logistic regression) for predicting 6-month pain (21% [OMPQ = 17%]/logistic = 29%) and disability (linear = 20%:[OMPQ = 19%]/logistic = 26%), whilst being comparable to the existing OMPQ reference standard, fell short of the a priori target of ≥30%.
Conclusions: The German version of the STarT-MSK-Tool is a valid instrument for use across multiple musculoskeletal conditions and is availabe for use in clinical practice. Comparison with the OMPQ suggests it is a good alternative.