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Found 6515 publications
DES and IIoT fusion approach towards real-time synchronization of physical and digital components in manufacturing processes
Publication Name: Reports in Mechanical Engineering
Publication Date: 2023-12-01
Volume: 4
Issue: 1
Page Range: 161-174
Description:
Today's manufacturing systems offer more products to meet specific needs. Complex production systems in rapidly changing environments result from product variation, shorter product life cycles, and supply chain expansion. A cyber-physical production system (CPPS) can use manufacturing and logistics data to plan, monitor, and control production. Discrete event simulation (DES) and digital twin (DT) technology can model and evaluate manufacturing and logistics processes using high-level decision support and process monitoring. The cost of collecting input data from different enterprise data sources and mapping it into models and the lack of qualified experts prevent the widespread use of these methods in industry, especially in small and medium-sized enterprises and larger multinational companies. This research aims to create a modular digital twin framework for manufacturing process optimization and real-time monitoring in an industrial environment with few components. The system can identify and track the product through the manufacturing cycle while updating the DT in real-time and can be used independently to collect input parameters for discrete event-driven simulations and even for automatic simulation building in the future. The framework's operation will be shown through an example. With the proposed IIoT (industrial internet of things) system integration, it can detect faults and warn of deviations from normal operation, and DT can drastically reduce data collection and model building and support model reusability, increasing sustainability.
Open Access: Yes
The Effect of Drying of Glycerol-Plasticized Starch upon Its Dielectric Relaxation Dynamics and Charge Transport
Publication Name: Journal of Polymers and the Environment
Publication Date: 2023-12-01
Volume: 31
Issue: 12
Page Range: 5389-5400
Description:
Carbohydrate polymers are promising materials for an eco-friendly future due to their biodegradability and abundance in nature. However, due to their molecular characteristics and hydrophilicity, are often complicated to be investigated via spectroscopic methods. Thermoplastic starch plasticized by glycerol was prepared through melt processing conditions using twin screw extruder. Here we show how the presence of water molecules affects the dielectric response and charge transport dynamics over broad frequency (10−1 to 107 Hz) and temperature (− 140 to 150 oC) ranges. Overall, 7 dielectric processes were observed and differentiation between electronic and ionic conductivities was achieved. Two segmental relaxation processes were observed for each sample, ascribed to the starch-rich and glycerol-rich phases. Although the timescales of the two segmental relaxations were found different, both arise from the same temperature, giving thus an alternative explanation on what is reported in the literature. The origin of the σ-relaxation was attributed to hydrogen ions and was found to be proportional to the ionic conductivity according to the Barton, Nakajima and Namikawa relation. The presence of water molecules was found to enhance the ionic conductivity, indicating that water contributes charge carriers when compared to the dried sample. Graphical Abstract: [Figure not available: see fulltext.]
Open Access: Yes
Comparison of Field and Standard Random Vibration for Small-Sized and Stacked Shipments during Parcel Delivery
Publication Name: Journal of Testing and Evaluation
Publication Date: 2023-11-01
Volume: 51
Issue: 6
Page Range: Unknown
Description:
In recent years, the volume of parcel shipments has increased significantly because of the rise in popularity of online shopping. This article focuses on the last mile segment of the parcel shipment, especially on the vibration behavior of the packages and van platform during transportation and the laboratory simulation of transportation vibration circumstances. The goal of this study is to measure in the field the vibration levels of small, stacked parcels and compare the results with measured vibration levels from the same measuring setup in the laboratory using ASTM D7386-16, Standard Practice for Performance Testing of Packages for Single Parcel Delivery Systems, vibration test method. For the measurements, three-layers of stacked small boxes with data recorder were set up into a delivery van to observe the vibration levels for the boxes inside and on the platform of the van, along different road conditions. The power spectral density spectra and overall Grms values of vibration intensity were presented and compared in four sections of frequency range between 1-200 Hz. The results indicate that the proposed vibration simulation does not correlate well with typical field vibration levels of the van platform and stacked packages. Based on the results, the packaging testing process can be developed as a more realistic preshipment testing process to avoid under-testing or over-testing of small parcels, thereby eliminating unnecessary packaging costs or damages.
Open Access: Yes
DOI: 10.1520/JTE20220490
The impact of the coronavirus pandemic on the mental health of critical care workers
Publication Name: Orvosi Hetilap
Publication Date: 2023-10-22
Volume: 164
Issue: 42
Page Range: 1646-1655
Description:
Introduction: The coronavirus pandemic has focused attention on the importance of critical care and highlighted the shortage of critical care specialists. Due to increasing workloads and high mortality rates, healthcare professionals were exposed to higher levels of physical and psychological stress during the pandemic than before. Objective: Our study investigated the effects of the coronavirus outbreak on the emotional, mental and moral stress of intensive care professionals. Method: Our workgroup performed paper-based surveys among caregivers in the Department of Anaesthesiology and Intensive Therapy at Semmelweis University. The first survey was conducted at the start of the pandemic in 2020, the second survey was conducted after the third wave in 2021. We applied validated questionnaires (Professional Quality of Life, Demoralization Scale, Perceived Stress Scale, Impact of Event Scale, and Posttraumatic Growth Inventory), collected demographic data and information on lifestyle, recreation, dietary habits, and accepting psychological support. Results: The number and demographic characteristics of the participants in the two studies are different, reflecting the changes in the workforce during the pandemic. Our results revealed no differences between the working and socio-demographic groups before the outbreak, however, one year later, nurses scored significantly higher on all negative psychological scales compared to other groups. Only a minority of the respondents had sought psychological support (9.5–12.7%), although more than a third of respondents reported the need for psychological support. Employees in new work positions showed significantly increased posttraumatic growth (2.91 ± 0.82 vs. 2.20 ± 1.06, p = 0.016). Discussion: These findings demonstrate that nurses are the most strained workgroup during an uncertain and stressful period. The available mental support alone is not enough to help caregivers. Conclusion: Further steps are needed to improve the mental health of critical care workers
Open Access: Yes
CHARACTERISTICS OF SEGMENTS ACCORDING TO THE PREFERENCE SYSTEM FOR JOB SELECTION, OPPORTUNITIES FOR EFFECTIVE INCENTIVES IN EMPLOYEE GROUPS
Publication Name: Decision Making Applications in Management and Engineering
Publication Date: 2023-10-01
Volume: 6
Issue: 2
Page Range: 557-580
Description:
In addition to economic challenges, employers are also facing a growing generation gap. Generations that are significantly different in terms of values, mindsets and preferences need to be effectively managed in a workplace, which requires complex solutions. In this paper we present sub results of our primary research. In a quantitative procedure, we conducted a pre-tested standardized questionnaire online survey with random sample making method, resulting in 1146 evaluable questionnaires. Descriptive statistics to evaluate the results presented in this study. Descriptive statistics, bivariate and multivariate analyses were applied to process the quantitative results, to test the hypotheses put forward. The main focus of our research is to investigate the factors that influence employees' choice of jobs, and we analyzed the structure of their preference system. As a result of the research, we were able to identify distinct clusters according to the preference system of job selection. In the context of the resulting segments, we also analyzed which motivational tools could be most effective in encouraging higher performance. We believe that our research has useful implications for practice, by highlighting how to differentiate the pool of employees in terms of job choice and how to apply effective incentives to a specific segment.
Open Access: Yes
The past, the present and the future of online road vehicle diagnosis from car and scan tool communication perspective
Publication Name: Advances in Transdisciplinary Engineering
Publication Date: 2023-09-15
Volume: 39
Issue: Unknown
Page Range: 52-58
Description:
In the luxury vehicle class, online internet connection has become a standard feature in the recent years. This process is likely to spread completely in all vehicle categories in the coming years. In the past, computer supported vehicle diagnostics started with On-Board Diagnostic (OBD) I standard in the late 1960's. This has been followed by OBD II in 1996, which allows a fully standardization regardless of vehicle manufacturer and models, based on a generic scan tool. Even its communication with the vehicle electronic architecture has been developed rapidly followed by the new technologies. This way of car analysis has been extended also for non-emission related functions. Online data collecting and analysis provides not only solutions in the car production and service but in its development process too. For example, it can help you to set realistic thresholds by defining an OBD strategy for many in-car systems and functions to avoid customer complaints, warranty costs and recalls afterwards. From predictive maintenance / repair perspective it is possible to monitor material properties, vibrations, damages potentials also in processes e.g. welding and soldering. The dynamic development of telecommunication and automotive technologies hand in hand will provide completely new ways for 'car to diagnostics back end' communication in the future without using a scan tool device and its physical in-vehicle interface.
Open Access: Yes
DOI: 10.3233/ATDE230419
Effect of Different Plant Growth-Promoting Rhizobacteria on Biological Soil Properties, Growth, Yield and Quality of Oregano (Origanum onites L.)
Publication Name: Agronomy
Publication Date: 2023-10-01
Volume: 13
Issue: 10
Page Range: Unknown
Description:
Intensive agriculture uses continuous chemical fertilizers to increase crop yields, but excessive use of fertilizers leads to environmental pollution, permanent changes in physicochemical conditions in soil ecology, deterioration of soil biological health, leaching of nutrients, surface and groundwater pollution and eutrophication. Plant growth-promoting rhizobacteria (PGPR) are becoming increasingly important for ensuring crop safety, increasing nutrient uptake and output, lowering fertilizer costs, preventing environmental contamination and promoting sustainable agriculture and agricultural resources. Therefore, the purpose of this study was to identify and evaluate the effects of fifteen bacteria strains that were isolated from various acidic rhizospheric soils as biofertilizers on soil biological properties. Growth, yield and quality traits were analyzed, and various PGPR were identified using 16S ribosomal RNA of Turkish oregano. Fifteen bacterial inoculations with 1-aminocyclopropane-1-carboxylate (ACC) deaminase, N2 -fixing, P-solubilizing and/or IAA-producing genes were used in the experiment, which was carried out in a randomized block design with five replicates (each with three pots) and a control without inoculation. Increased biological activity in soil inoculated with bacteria with multiple traits was confirmed by high C and N content in microbial biomass, urease, dehydrogenase and acid and alkaline phosphatase activities. Essential oil content, oil yield, thymol and carvacrol contents increased by 0.5–40.1%, 5.9–71.9%, 0.07–16.7% and 0.3–9.2%, respectively, as a result of bacterial inoculation. Oil content ranged from 2.02% to 2.83%; carvacrol (66.1–72.2%) was the main constituent, followed by thymol (14.5–16.9%) and linalool (1.38–3.68%). Two large PGPR groups were formed based on genetic distance analysis. Responses were variable and depended on the inoculant strain and the parameters being evaluated. The results indicate PGPR has clear potential for improving the yield of cultivated aromatic and essential oil plants, such as oregano.
Open Access: Yes
A case study on the capacity of a signalized circular intersection
Publication Name: Pollack Periodica
Publication Date: 2023-09-25
Volume: 18
Issue: 3
Page Range: 106-112
Description:
Analyzing the capacity of a signalized circular intersection is an essential aspect of traffic flow management. With the increased number of vehicles at the intersection, it is preferable to examine ways to increase capacity without altering the existing geometric features. A signalized circular intersection on the national highway in Gyor, Hungary, between 47° 40′ 43.7988″ N and 17° 39′ 37.6668″ E is chosen and analyzed for capacity enhancement. The survey is conducted using 360-degree cameras. The PTV Vissim software is then used to construct a model based on the current and projected vehicle counts, as well as the current and proposed options. The result shows that it is possible to increase the capacity of signalized circular intersections without altering the geometric features.
Open Access: Yes
