4653 research outputs found
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Energetic, exergetic, exergoeconomic, environmental and sustainability analyses of a solar, geothermal and biomass based novel multi-generation system for production of power, hydrogen, heating, cooling and fresh water
No full textThe present study proposes and investigates a novel solar, geothermal and biomass based multi-generation system producing multiple outputs to generate power, hydrogen, heating, cooling, and fresh water. Parabolic trough solar collectors, a two stages Rankine cycle, two organic Rankine cycles, two absorption cooling systems, a gas turbine system, a once-through (OT) multi stage flash (MSF) desalination unit, a geothermal unit, a heat pump, an electrolyser and a thermal energy storage are used as sub-systems. The novelty of the system is to focus on novel sub-system design pattern for the proposed multi-generation system by using multiple energy inputs as there is a gap about those studies in the literature. The overall system performance is evaluated from energetic, exergetic, exergo-economic, environmental (4E) and sustainability points of view by using the EES software package. The total installed power and hydrogen mass flow rates are 7.76 MW and 3.52 kg/h, respectively. The energy and exergy efficiency values of the overall system are found to be 65.55% and 27.09%. Fresh water flow rate is calculated to be 6.16 kg/s with 10 stages. The overall unit product cost is determined to be 21,79 $/GJ and the overall social ecologic factor is calculated to be 1.37.Engineering, Environmental || Engineering, Chemica
THE WHATSAPP APPLICATION USE AS A SUPPORT SERVICE IN DISTANCE EDUCATION: A CASE ANALYSIS
No full textThis study aims to reveal the strengths and limitations of the WhatsApp application as a support service in distance education, conducted through a learning management system during the Covid-19 pandemic, and make suggestions on improving its use in this capacity. Despite the lack of readiness on the part of the students and the lack of sufficient knowledge regarding distance education during the pandemic, many universities had to revert to emergency remote teaching. This situation necessitated the intensive use of various support services for the students to get the most out of their emergency remote teaching However, their lack of experience with distance education prevented them from using the support services offered by learning management systems. Due to the increasingly widespread use of mobile technologies, one of the support services used by course instructors became the WhatsApp application. The following research is a qualitative case study. The sample for the study was determined through purposive sampling. The data was analyzed using the content analysis method. Nvivo qualitative data analysis software was used to contribute to the detailed and versatile data analysis. The most important results of the study were that the application supported and strengthened distance learning by allowing instant communication, but that the absence of a moderator caused various limitations in this communication. In addition, it was concluded that incorporating natural language processing techniques into learning management systems and clearly stated rules by course instructors improved the use of such instant communication applications as a support service for distance education.Education & Educational Researc
The impact of geopolitical risks on connectedness among natural resource commodities: A quantile vector autoregressive approach
No full textThis study examines the impact of global geopolitical risk on connectedness among major natural resource commodities. We implemented a Quantile Vector Autoregressive connectedness estimation approach from 5 January 2010 to 3 March 2023, including many geopolitical turbulences, such as the Russian-Ukrainian war. We found high connectedness under both extraordinarily high and low return conditions. The extreme return shocks in metals tended to spillover to energy commodities. The spillover index peaked during important economic, political, and financial developments. In addition, geopolitical risk drives connectedness among natural resources commodities under average market conditions. Our results may help investors with portfolio optimization and risk management practices and guide policymakers toward attaining financial market stability.Environmental Studie
Multi-timescale boosting for efficient and improved event camera face pose alignment
No full textThe success of event camera (EC) vision in certain types of applications has been steadily shown thanks to energy-efficient sparse sensing, high dynamic range, and extremely high temporal resolution. However, the utilization of ECs for facial processing tasks has remained rather limited. To enable high energy efficiency for large face pose alignment, which is a crucial facial pre-processing stage, we aim at leveraging EC by effective adaptation of the processing rate proportional to facial movement intensity. For this purpose, we propose a novel alternative to the commonly employed constant time frame and event count frame strategies which combines their advantages and provides the benefits of supervised learning. This is realized by a multi-timescale boosting framework that can generate highly sparse pose-events at a variable rate via detection-based online timescale selection. Although detectors of multiple scales with boosted sensitivities operate as a cascade, our method provides minimal delay essential for real-time applications. Comprehensive evaluations show that the proposed multi-timescale processing substantially improves the performance-efficiency trade-off over singletimescale frames and markedly over event count frames. Mega-floating-point-operations-per-second ranges from 2.5 at the moderate motion clips to 6.5 at the intense motion clips, with negligible computation in the absence of activity. Also, alignment errors are considerably reduced by online selection of small timescales at fast head motion and of bigger timescales at slower motion or local activity of lips and eyes. Being orthogonal and complementary to spatial domain techniques, the proposed approach can also be conveniently integrated with future advances for further performance/efficiency improvements or for alignment extensions.Computer Science, Artificial Intelligence || Engineering, Electrical & Electroni
Workplace aggression profiles and employee role behaviors: Mediation of multiple negative emotions
No full textPsychology, Multidisciplinar
The Mediating Effect of Trust and Perceived Value on the Relationship between Corporate Image and Online Shopping Intention: A Study on Consumer Durables
No full textThe study aims to reveal factors that affect customers' extension from the offline to the online channel and investigate how these factors influence consumers' behavior toward online channel adoption. We examine how offline corporate image, trust, and perceived value affect consumers' online shopping intentions. This study focuses on electrical appliances, both brown and white goods. A convenience sampling method was followed for the data collection process using both an online and offline survey method. Data were collected from 219 consumers who had purchased an electric appliance (brown or white goods, e.g., dishwasher, refrigerator, oven) within the last three months. Data were analyzed with structural equation modeling, and mediation effects of offline perceived value and trust were tested with SPSS process macro. Our empirical results suggest that consumers' offline-based trust and value perceptions significantly drive their online shopping intentions for durable products. The findings also reveal that offline trust and perceived value mediate the relationship between corporate image and online shopping intention.Communicatio
Event Study Design for Modeling Early Relaxation in Turkish Public with COVID-19 Vaccine
No full textObjective:Vaccination is crucial to fighting the coronavirus disease (COVID-19) pandemic. A large body of literature investigates the effect of the initiation of the COVID-19 vaccination in case numbers in Turkey, including the resistance and willingness to taking the vaccine. The effect of early relaxation in the Turkish public with the initiation of vaccination on new daily cases is unknown.Methods:This study performs an event study analysis to explore the pre-relaxation effect of vaccination on the Turkish public by using daily data of new cases, stringency index, and residential mobility. Two events are comparatively defined as the vaccination of the health personnel (Event 1) and the citizens age 65 and over (Event 2). The initial dates of these events are January 13 and February 12, 2021, respectively. The length of the estimation window is determined as 14 days for the 2 events. To represent only the early stages of the vaccination, the study period ends on April 12, 2021. Thus, whereas the event window of Event 1 includes 90 observations, Event 2 covers 60 observations.Results:While average values of residential mobility, stringency index, and daily numbers of cases are 15.36, 71.03, and 11 978.93 in the estimation window for Event 1, these averages are 8.89, 70.88, and 17 303.20 in the event window. For Event 2, the same average values are 9.14, 69.38, and 7 664.93 in the estimation window and 8.25, 71.12, and 22 319.10 in the event window. When 14-day abnormal growth rates of the daily number of cases for Event 1 and Event 2 are compared, it is observed that Event 1 has negative growth rates initially and reaches a 7.59% growth at most. On the other hand, Event 2 starts with a 1.11% growth rate, and having a steady increase, it reaches a 23.70% growth in the last 14 days of the study period.Conclusion:The preliminary result shows that, despite taking more strict governmental measures, while residential mobility decreases, the daily number of COVID-19 cases increases in the early stages of vaccination compared to short pre-periods of it. This indicates that the initiation of vaccination leads to early behavioral relaxation in public. Moreover, the effect of Event 2 on the case numbers is more significant and immediate, compared to that of Event 1, which may be linked to the characteristic of the Turkish culture being more sensitive to the older adult population.Public, Environmental & Occupational Healt
Machine Learning Based Multipath Processing Architecture for Mobile IoT Indoor Positioning
No full textIn this work, we propose a novel machine learning-based architecture that processes the Channel Impulse Response (CIR) for mobile Internet of Things (IoT) indoor localization. Our architecture is comprised of three stages: First, it pre-processes the Channel Impulse Response of the channel from the mobile device to each anchor by lumping the channel tap values at a configurable resolution. Second, the Machine Learning-Based Multipath Profile Processing block applies feature selection to the pre-processed channel taps. Third, in the Machine Learning Based Feature Fusion block, the selected features are combined to estimate the position of the mobile device. In order to test the performance of our architecture, we use two distinct datasets that were collected in home and office environments respectively. The results demonstrate that our work can significantly improve indoor localization accuracy. This work paves the way to significant performance improvements in indoor localization by processing the Channel Impulse Response via machine learning algorithms.Computer Science, Artificial Intelligence || Computer Science, Theory & Methods || Engineering, Electrical & Electronic || Telecommunication
Challenges for circular food packaging: Circular resources utilization
No full textPackaging is considered as one of the most important activities of the food supply chain. Even though it serves a vital role in both the supply chain management and manufacturing industry || knowledge base for the implementation of extended producer's responsibility for packaging is significantly ignored and inadequate. Thus, aim of this article is to identify and analyse the challenges to circular food packaging in the literature for reduced food waste and sustainable food supply chain. To reach this aforementioned aim, as an initial step, systematic literature review is conducted with 189 articles. Articles were gathered from databases including Web of Science (WoS), MDPI and Scopus. In total of 26 challenges are selected and classified under 7 categories. Moreover, findings provide a further analysis with multi-dimensional perspective to the circular food packaging including CE principles (9Rs), packaging materials and sub-sectors in food industry. The study ended with the interpretation of results and implications which will guide practitioners and policy makers.Food Science & Technolog
Leveraging corporate sustainability through responsible innovation: Capacity building with exploration and exploitation
No full textThe growing literature on corporate sustainability suggests its positive implications for organizations and stakeholders. Based on the social identity approach, the current study aims to investigate whether responsible innovation can leverage these sustainability advantages of companies to improve organizational commitment and competitiveness. Responsible innovation has been integrated into an original model as a construct that translates corporate sustainability into organizational outcomes to meet stakeholders' needs and to frame and solve the sustainability-related tensions in an ethical way. The study also attempts to examine the mediating impacts of exploration and exploitation orientations on the proposed link between corporate sustainability and responsible innovation. The model was validated by using the partial least squares structural equation modelling method on a sample of 196 middle managers in small businesses in Turkey. The findings reveal that responsible innovation has a significant mediation effect on the proposed links, and both exploration and exploitation elicit the innovation capacity in sustainability practices. The study also supports the argument on the positive impact of exploitation on exploration.Managemen