ENERGY CERTIFICATION AND ENERGY AUDIT OF HIGHER EDUCATION AS A METHODOLOGICAL TOOL TO IMPROVE THE ENERGY EFFICIENCY OF THE UNIVERSITY

BACKGROUND AND OBJECTIVES. Improving the energy performance of buildings is one of the least expensive ways to reduce energy consumption and greenhouse gas emissions. Building energy performance certification increases public knowledge about energy conservation and allows consumers and other decision makers to compare buildings based on their lifetime performance. In addition, energy performance certifications are an incentive for owners to improve the efficiency of existing buildings.METHODS. It is proposed to use in the process of energy certification and energy audit of university buildings collection and evaluation of basic information (including information about local climate, method of use, value of thermal conductivity coefficient and building envelope area, orientation) to determine the level of energy efficiency of the building on a generally accepted scale. In the Certificate of energy efficiency to take into account the calculated results from the assessment of the energy performance of the building.FINDINGS. It is suggested that the results of the energy certification of university buildings be presented in a simple, clear form, to ensure clarity, ease of use and comparability. For the energy certification of university buildings, a comparative labeling from A to G is proposed for use. The scale, on which the current national building standard is at "C," provides ample room for improving the rating of both new and existing buildings. If necessary, the scale should be expanded to add a label such as A1, A2, or A+, A++ when it comes to high-performance buildings.CONCLUSION. Accurate and reliable energy performance certification is a necessary foundation that will help ensure consumer confidence and the success of the certification program. The certification program must be clearly coordinated to ensure a smooth transition of the construction industry to the new rules.

Nonlinear Short-Run Adjustments between REITs and Stock Markets in the USA and Australia

This study examines whether nonlinear co-integration exists between real estate investment trusts (REITs) and corresponding stock markets in the United States and Australia. Moreover, we employ the smooth-transition, vector-error correction model (STVECM) including the generalized autoregressive conditional heteroskedasticity (GARCH) model to separately explore the adjustment efficiencies of the short-run REITs and corresponding stock returns in dynamics. The empirical results demonstrate that there is a nonlinear co-integration with structural breaks between the equity and mortgage REITs and stock markets in the US as well as between the REITs and stock markets in Australia. When large positive and negative deviations of STVECM exist, the speed of equilibrium adjustment of the S&P 500 index is greater than that of the Mortgage REITs index. Additionally, the higher the equilibrium adjustment of Australian/US REITs index, the greater the reversion of Australian/US REITs index. Meanwhile, this study is also interested in finding out whether the REIT indices in the US or Australia would serve as a leading indicator for price movements. The result findings may provide a good reference for the investors’ investment engaged in the areas of these two countries. JEL Classification: C22, D53, G14, L85. Keywords: REITs, STVECM, Nonlinear Granger causality, GARCH.

Extending DC Bus Utilization for Induction Motors with Stator Flux Oriented Direct Torque Control

This paper presents a method to extend the DC bus utilization on an induction motor (IM) by using a combination of Space-Vector Modulated Direct Torque Control (DTC–SVM) and conventional DTC. The scheme proposed in this paper exploits the advantages of both control methods. During the linear region, it allows for a low torque ripple and low current harmonic distortion (THD). During the overmodulation region, it allows for the fastest torque response up to the six-step operation region. In both regions, there is complete independence of the motor parameters. The paper describes a way to provide a smooth transition between the two control schemes. Non-linearities affect the stator flux angle estimation, which leads to the inability to decouple torque and flux. To overcome this problem, a novel PI-based control scheme as well as a simplification on the decoupling terms’ calculation are proposed. Simulation and experimental results are presented to verify the feasibility of the proposed method.

Hydrogen Storage and Transportation Technologies to Enable the Hydrogen Economy: Liquid Organic Hydrogen Carriers

Reliable storage and transportation of hydrogen at scale is a challenge which needs to be tackled to allow a robust and on-demand hydrogen supply when moving towards a global low carbon hydrogen economy with the aim of meeting net-zero climate goals. Numerous technologies and options are currently being explored for effective hydrogen storage and transportation to facilitate a smooth transition to the hydrogen economy. This paper provides an overview of different hydrogen storage and transportation technologies, focusing in more detail on liquid organic hydrogen carriers (LOHCs), its advantages and disadvantages, and future considerations for the optimisation of the LOHC technology.

Motion coordination control of planar 5R parallel quadruped robot based on SCPL-CPG

The parallel leg of the quadruped robot has good structural stiffness, accurate movement, and strong bearing capacity, but it is complicated to control. To solve this problem, a series connection of parallel legs (SCPL) was proposed, as well as a control strategy combined with the central pattern generator (CPG). With the planar 5R parallel leg as the research object, the SCPL analysis method was used to analyze the leg structure. The topology of CPG network was built with the Hopf oscillator as the unit model, and the CPG was the core to model the robot control system. By continuously adjusting the parameters in the CPG control system and changing the connection weight, and the smooth transition between gaits was realized. The simulation results show that the SCPL analysis method can be effectively used in the analysis of parallel legs, and the control system can realize the smooth transition between gaits, which verifies the feasibility and effectiveness of the proposed control strategy.

Simulation and predictive control of the gas transportation system in a large industrial zone

The article describes an approach to the operational and supervisory control of a gas transmission system for large industrial zones using a model predictive control, as well as analytical and simulation methods. The operational and supervisory control of the gas transportation system covers the time horizon from several hours to several days and involves performing several cyclically repeated actions. The authors propose a time series predictive model of the gas consumption parameter considering temperature weather conditions, which is extended based on accounting for the correlation relationships between the consumption volumes of each consumer. The control methods used today, reacting to the current deviations from the planned regime, a priori do not allow achieving the best results. A significant increase in the stability of control and a reduction in the cost of fuel and energy resources can be achieved by using the control method based on predictive models. In this case, the control object model is used to predict its behavior within the selected time horizon, and optimal control actions are selected on this basis. The process of predicting and selecting control actions is periodically repeated, constantly changing the time horizon boundaries. The described method of changing the flow diagram consists either in changing all the flows at the same time or in a preemptive and smooth transition based on the introduction of a weighted flow diagram for various stationary modes, provided that their mismatch is minimized at neighboring time intervals corresponding to the intervals of constancy of consumption requests.

HHO-Based Vector Quantization Technique for Biomedical Image Compression in Cloud Computing

In the present digital era, the exploitation of medical technologies and massive generation of medical data using different imaging modalities, adequate storage, management, and transmission of biomedical images necessitate image compression techniques. Vector quantization (VQ) is an effective image compression approach, and the widely employed VQ technique is Linde–Buzo–Gray (LBG), which generates local optimum codebooks for image compression. The codebook construction is treated as an optimization issue solved with utilization of metaheuristic optimization techniques. In this view, this paper designs an effective biomedical image compression technique in the cloud computing (CC) environment using Harris Hawks Optimization (HHO)-based LBG techniques. The HHO-LBG algorithm achieves a smooth transition among exploration as well as exploitation. To investigate the better performance of the HHO-LBG technique, an extensive set of simulations was carried out on benchmark biomedical images. The proposed HHO-LBG technique has accomplished promising results in terms of compression performance and reconstructed image quality.

Regulating Work Experience Programs in the Greek Post-Secondary Education: The Case of Traineeships

The smooth transition of young people to the labor market and their competency in successfully planning and developing their careers constitute key aims of all modern education systems. The implementation of work placements plays an important role in the realization of these aims by enhancing the communication between the education providers and the world of work, and by contributing to the development of professionally oriented competences by young learners. The paper focuses on traineeships, a particular type of work placement, which is implemented by post-secondary education institutions in Greece. A traineeship includes a variety of training processes with clear objectives and predetermined assessment strategies, which help trainees to gain professional skills and experience through an experiential process. Its ability to exercise a strong influence on the professional prospects of young people led many education institutions to integrate traineeship opportunities in their study program either as a compulsory component or as a non-mandatory option. The paper analyses the traineeship component of the study programs of three post-secondary education institutions in Greece, i.e. Institutes of Vocational Training (IVTs), Higher Education Institutions (HEIs) and Technological Educational Institutes (TEIs). More analytically, the paper investigates the legislative provisions concerning the organization and implementation of student traineeships, and records the evolution of the particular learning option over the years. In addition, it attempts to identify indications of interaction between post-secondary education institutions as regards the organization and the particular features of student traineeship schemes, which may imply the development of mutual learning. The paper concludes by articulating some remarks regarding the implementation of traineeships in Greek post-secondary institutions and the improvement of their organizational and operational characteristics.