•Developed machine learning models for HVAC electricity consumption prediction.•Compared the performance of feed-forward back-propagation artificial neural network (ANN) with random forest (RF).•The ...ANN model performed marginally better than the RF model.•RF model can be used as a variable selection tool.
Energy prediction models are used in buildings as a performance evaluation engine in advanced control and optimisation, and in making informed decisions by facility managers and utilities for enhanced energy efficiency. Simplified and data-driven models are often the preferred option where pertinent information for detailed simulation are not available and where fast responses are required. We compared the performance of the widely-used feed-forward back-propagation artificial neural network (ANN) with random forest (RF), an ensemble-based method gaining popularity in prediction – for predicting the hourly HVAC energy consumption of a hotel in Madrid, Spain. Incorporating social parameters such as the numbers of guests marginally increased prediction accuracy in both cases. Overall, ANN performed marginally better than RF with root-mean-square error (RMSE) of 4.97 and 6.10 respectively. However, the ease of tuning and modelling with categorical variables offers ensemble-based algorithms an advantage for dealing with multi-dimensional complex data, typical in buildings. RF performs internal cross-validation (i.e. using out-of-bag samples) and only has a few tuning parameters. Both models have comparable predictive power and nearly equally applicable in building energy applications.
Bullying remains a pervasive issue that affects many children worldwide, with devastating consequences that ripple through their lives and communities ....
Purpose
The purpose of this study is to examine the relationship between knowledge-hiding behaviors (evasive hiding, playing dumb and rationalized hiding) and employees’ silence (defensive silence, ...relational silence and ineffectual silence). Besides, this paper investigates the relation mediated by psychological contract breach.
Design/methodology/approach
The data were collected with three-time lags (40 days each) through a structured questionnaire from 389 employees of registered software houses in Pakistan. The structural equation modeling (partial least squares) approach is used for data analysis.
Findings
The findings of this study confirm that knowledge-hiding behaviors have a significant and positive relationship with employees’ silence, and psychological contract breach significantly mediates the relationship between knowledge-hiding behaviors and employees’ silence.
Practical implications
The implications of this study are very supportive to the knowledge-intensive organizations, i.e. software houses. The management should increase the knowledge sharing and trust culture among employees to discourage the knowledge-hiding behaviors among employees. Moreover, supervisors should develop trust among employees, motivate them to avoid knowledge hiding and encourage the employees to raise their voices against their problems in a formal way.
Originality/value
The present study highlights the impact of different dimensions of knowledge hiding on employees’ silence and the role of psychological contract breach as a mediator in this scenario.
This paper proposes a fractional order sliding mode control (FOSMC) strategy for grid-connected doubly fed induction generator (DFIG). The novel approach aims to directly control the active/reactive ...power output of a DFIG-based wind energy conversion system with FOSMC, which has never been utilized in the control of DFIG. The fractional order sliding mode control with disturbance is introduced and the Caputo derivative is employed in constructing the sliding surface. Meanwhile, an enhanced exponential reaching law is utilized in order to mitigate the chattering phenomenon in the sliding stage and accelerate the reaching progress in the meantime. A comparative study is conducted subsequently to verify the superior performance of the proposed FOSMC control scheme over that of the conventional sliding mode control and the vector control approach. A steady state simulation is first conducted to tune the parameters of the FOSMC. A variable wind condition is subsequently simulated to compare the performance of those methods. After that, simulations with background harmonics of the grid voltage and parameter perturbation are considered. Ultimately, an experimental test is conducted to further validate the proposed method. The superior performance and the effectiveness of the FOSMC are fully validated with the above four comparative tests.
Cryptosystems are commonly deployed to secure data transmission over an insecure line of communication. To provide confusion in the data over insecure networks, substitution boxes are the solitary ...components for delivering a nonlinear mapping between inputs and outputs. A confusion component of a block cipher with high nonlinearity and low differential and linear approximation probabilities is considered secure against cryptanalysis. This study aims to design a highly nonlinear substitution-permutation network using the blotch symmetry of quantum spin states on the Galois field GF (2
). To observe the efficiency of the proposed methodology, some common and advanced measures were evaluated for performance, randomness, and cryptanalytics. The outcomes of these analyses validate that the generated nonlinear confusion components are effective for block ciphers and attain better cryptographic strength with a high signal-to-noise ratio in comparison to state-of-the-art techniques.
In recent decades, climate change and environmental pollution have been at the center of global environmental debates. Nowadays, researchers have turned their attention to the linkage between real ...output and environmental quality and test the environmental Kuznets curve. Majority of the studies focus on a single pollutant aspect and measure the deterioration of the environment through carbon emission (CO
2
) only. In contrary, the current study uses a comprehensive proxy, ecological footprint, to measure the environmental quality of the sixteen Central and Eastern European Countries (CEECs). The aim of this paper is to discover the impact of financial development, economic growth, and energy consumption (renewable and non-renewable) on the environment. In addition, for the first time, the current study includes biocapacity and human capital in the growth–energy–environment nexus in the case of CEECs. In doing so, we used annual data of sixteen CEE countries in perspective of the One Belt One Road (OBOR) initiative and cover the period of 1991–2014. For reliable findings, this study focuses on second-generation econometric approaches to check stationarity, cross-sectional dependency, and co-integration among the model parameters. The long-run estimations of the “Dynamic Seemingly Unrelated-co-integration Regression” (DSUR) signify that the effect of economic growth on ecological footprint is not stable and validate N-shaped relationship for cubic functional form between per capita income and ecological footprint (environmental quality). Empirical evidence divulges that financial development and energy use significantly contribute to environmental degradation while renewable energy improves environmental quality by declining ecological footprint significantly. Moreover, the significant effects of biocapacity and human capital are positive and negative on the ecological footprint, respectively. In robustness check through the “Feasible Generalized Least Square” (FGLS) and “Generalized Method of Moment” (GMM) models, we found consistent result. Lastly, the “Dumitrescu-Hurlin (D-H) Panel Causality Test” demonstrates that two-way causal relationship exists between EF and GDP, EF and FD, EF and EU, EF and BC, and EF and HC, while one-way causality is running from RE to EF. This study puts the present scenario of CEE economies in front of the policymakers and suggests that they should consider the vital role of renewable energy and human capital to get sustainability.
•Reviews energy metering and environmental monitoring technologies along with a discussion on their working principle, types and cost comparison of most widely available meters and sensors.•Reviewed ...social, economic, environmental and legislative drivers for the installation of these technologies.•Presented a table to summarise energy legislation and regulations in different countries.•Factors influencing the selection of meters and sensors are also discussed in detail.•Reviews most widely used communication and network technologies.•Discusses possible future research directions and challenges.
Buildings are responsible for 40% of global energy use and contribute towards 30% of the total CO2 emissions. The drive to reduce energy consumption and associated greenhouse gas emissions from buildings has acted as a catalyst in the increasing installation of meters and sensors for monitoring energy use and indoor environmental conditions in buildings. This paper reviews the state-of-the-art in building energy metering and environmental monitoring, including their social, economic, environmental and legislative drivers. The integration of meters and sensors with existing building energy management systems (BEMS) is critically appraised, especially with regard to communication technologies and protocols such as ModBus, M-Bus, Ethernet, Cellular, ZigBee, WiFi and BACnet. Findings suggest that energy metering is covered in existing policies and regulations in only a handful of countries. Most of the legislations and policies on energy metering in Europe are in response to the Energy Performance of Buildings Directive (EPBD), 2002/91/EC. However, recent developments in policy are pointing towards more stringent metering requirements in future, moving away from voluntary to mandatory compliance. With regards to metering equipment, significant developments have been made in the recent past on miniaturisation, accuracy, robustness, data storage, ability to connect using multiple communication protocols, and the integration with BEMS and the Cloud – resulting in a range of available solutions, selection of which can be challenging. Developments in communication technologies, in particular in low-power wireless such as ZigBee and Bluetooth LE (BLE), are enabling cost-effective machine to machine (M2M) and internet of things (IoT) implementation of sensor networks. Privacy and data protection, however, remain a concern for data aggregators and end-users. The standardization of network protocols and device functionalities remains an active area of research and development, especially due to the prevalence of many protocols in the BEMS industry. Available solutions often lack interoperability between hardware and software systems, resulting in vendor lock-in. The paper provides a comprehensive understanding of available technologies for energy metering and environmental monitoring; their drivers, advantages and limitations; factors affecting their selection and future directions of research and development – for use a reference, as well as for generating further interest in this expanding research area.
Teachers’ education has a pivotal role in the process of societal change and for leading towards a sustainable future. The current study aimed at investigating the effect of a course regarding ...education for sustainable development on the student-teachers’ attitude towards sustainable development. The data were collected from student teachers in two stages; in the first stage, data were collected from 287 students to validate the questionnaire while in the second stage data were collected from the experimental and controlled group. Structural equation modelling technique, paired and independent sample t-tests were applied for data analysis. The results of the quantitative and qualitative data indicate a positive change in the student-teachers’ attitude towards sustainable development. Student-teachers who studied education for sustainable development subject during their course-work were surveyed to determine if they had a positive attitude towards sustainable development compared to their counterpart student-teachers who did not study education for sustainable development subject. Results of the study advocate the need and potential of education for sustainable development in different academic programs, especially teachers’ education program in Pakistan, is to enhance the students’ attitude towards sustainable development.
•Education for Sustainable Development (ESD) plays a significant role in sustainable future.•Analysis of ESD course on pre-service teachers’ attitude and behaviour towards sustainable development (SD).•A significant increase in student-teachers’ attitude towards sustainable development (SD) after studying the ESD course.
Display omitted
•New fluorene based sensors 4 and 5 were synthesized and characterized.•Ultrasensitive sensing of picric acid (PA) was detected selectively with low limit of detection (LOD) of 22 ppt ...for sensor 4.•Sensor 5 exhibited PA detection with very low LOD of 0.23 ppt through FRET, IFE and PET based fluorescence quenching mechanisms.•Both sensors were used for rapid detection of picric acid in real samples.•Sensors displayed ultra-selective colorimetric detection of picric acid.•Plausible interaction of sensors with PA was supported by 1HNMR, UV Vis., DLS, and computational studies.
New butterfly-shaped π-extended sensors 4 and 5 were synthesized through the Knoevenagel condensation and the Suzuki-Miyaura coupling reaction. Sensors were employed for sensitive detection of nitroaromatics. Among nitroaromatic compounds (NACs), sensors 4 and 5 exhibited ultrasensitive fluorescence quenching response to picric acid (PA) with quenching efficiency >45 and >260 folds and limit of detection (LOD) 22.0 and 0.23 ppt (parts per trillion), respectively. This ultra-sensitivity was contributed by FRET and IFE processes. Selective interaction of sensors with PA was evaluated by fluorescence, UV–Vis., 1H NMR titration, dynamic light scattering (DLS), and density functional theory (DFT) calculations. These sensors were successfully employed for detection of picric acid in real water samples. Interestingly, sensors 4 and 5 showed selective colorimetric recognition of picric acid. Moreover, sensors’ coated test strips were fabricated for an immediate naked eye detection of PA that demonstrated rapidity, simplicity, and convenience for on-site detection of PA. Robust sensitivity for PA illustrated that these sensors can be employed in the development of new detection tools for PA analysis in real samples.
Chromium (Cr) is a toxic heavy metal that contaminates soil and water resources after its discharge from different industries. It can act as carcinogen and mutagen for biological systems. ...Microbe-assisted phytoremediation is one of the most emergent and environment friendly technique used for detoxification of Cr from Cr-contaminated soils. In this study, wheat as a test crop was grown under varying stress levels (0, 50, 100 and 200 mg/kg) of Cr in a pot experiment under a complete randomized design. Alleviative role of Staphylococcus aureus strain K1 was assessed by applying as a treatment in different combinations of zinc oxide nanoparticles (0, 50, 100 mg/L). Growth and yield attributes data presented nurturing impact of bacterial inoculation and ZnO NPs in improvement of wheat defense system by decreasing Cr toxicity. Increase in chlorophyll and carotenoids contents, antioxidant enzymes (SOD, POD, APX, CAT) activities and nutrient uptake also confirmed the mitigative potential of bacterial inoculation when applied solely or in combination with ZnO NPs. The Cr accumulation in different parts of plant was significantly reduced with the application of NPs and S. aureus strain K1. Taken together, the results showed that combined application of Staphylococcus aureus strain K1 and ZnO NPs detoxifies the effects of Cr on wheat plants and boosts its growth, physiology and defense system.
Display omitted
•Chromium toxicity reduced the plant growth, physiological along with oxidant and antioxidant activity.•ZnO application improves enzymatic activity by enhancing growth and physiology of wheat plants.•Staphylococcus aureus strain K1 reduced oxidative stress and improved plant growth.•S. aureus bio-transformed the chromium Cr6+ into Cr3+ and decreased its uptake by plant.
PDF
