Papers by nikolaos Asimopoulos
Sustainable Energy Technologies and Assessments, Apr 1, 2021
Abstract In high Renewable Energy Sources (RES) penetration cases and especially whenever local g... more Abstract In high Renewable Energy Sources (RES) penetration cases and especially whenever local grids are considered, the absence of coordination between RES production and demand includes the risk of reduced reliability of power supply to the consumers. In this paper, an innovative, cost-effective and easy to install technology is introduced that allows PV sun-tracking systems to regulate their actual energy production according to the network demands instead of relying on the inverters to manage the excessive energy. This method is suitable for existing applications where energy storage is not possible. In addition, a main advantage of the proposed method is that it protects the PV panels from high temperatures when network loads permits, expanding thus the life span of a system. This technology utilizes control-automation and communication tools, to adjust the PV power production of distributed sources with respect to the needs of the consumers as well as to the technical and economic requirements of the electricity grid and the power market. The main idea is to use the sun-tracking system, i.e. by changing the position of slave trackers, for achieving maximum power and to determine the unserved power, so that enables charging and market integration potential. The system can be adopted to almost all sun-tracking systems, whereas the signal transmission towards the PV system is accomplished by the newly-introduced and the cost-effective Digital Audio Broadcasting (DAB) energy data transmission protocol.
2017 IEEE International Conference on Environment and Electrical Engineering and 2017 IEEE Industrial and Commercial Power Systems Europe (EEEIC / I&CPS Europe)
Demand Side Management (DSM) refers to a set of measures targeting at load modifications in perio... more Demand Side Management (DSM) refers to a set of measures targeting at load modifications in periods of high electricity generation costs, supply shortage and grid" s techno-economic constrains. This paper proposes a novel DSM strategy for load management of consumers that are eligible for the implementation of Real-Time Pricing (RTP) schemes. The DSM strategy is formulated as a constrained optimization problem that can be easily solved and therefore, making it an ideal tool for Retailers" decision making framework in day-ahead competitive electricity markets.
SHS Web of Conferences
Medical industry produces a significant portion of data whereas by adopting various Machine Learn... more Medical industry produces a significant portion of data whereas by adopting various Machine Learning models it can make accurate predictions about public healthcare that can be generalised. Transfer learning improves traditional machine learning by transferring the knowledge learned in one or more tasks and by using it for learning improvement in a related target task. In the current study, transfer learning with random forests was applied. Four datasets of medical interest obtained from the University of California, Irvine (UCI) Machine Learning Repository were used i.e., the BUPA-Liver Disease Dataset, the Breast Cancer Wisconsin Dataset, the Cleveland Heart Disease Dataset, and the Pima Indians Diabetes dataset. To our knowledge, there has been no study that applied Random Forests and Transfer Learning for these datasets. According to our results, our proposed method could provide significant accuracy rates in terms of diagnosing these disorders. Specifically, the classification ...
SHS Web of Conferences
Neural Network’s basic principles and functions are based on the nervous system of living organis... more Neural Network’s basic principles and functions are based on the nervous system of living organisms, they aim to simulate neurons of the human brain to solve complicated real-world problems by working in a forward-only manner. A recursive Neural Network on the other hand is based on a recursive design principle over a given sequence input, to come up with a scalar assessment of the structured input. This means that is ideal for a given sequence of input data that is when processed dependent on its previous input sequence, which by default are used in various problems of our era. A common example could be devices such as Amazon Alexa, which uses speech recognition i.e., given an audio input source that receives audio signals, tries to predict logical expressions extracted from its different audio segments to form complete sentences. But RNNs do not come with no problems or difficulties. Today’s problems become more and more complex involving parameters in big data form, therefore a n...
SHS Web of Conferences
Chatbots are artificial intelligence systems that comprehend the intent, context, and sentiment o... more Chatbots are artificial intelligence systems that comprehend the intent, context, and sentiment of the user, interact properly with them leading to an increased development of their creation, the past few years. In this study, Convolutional Neural Networks (CNNs) are applied as the classifier and some specific tools for tokenization are used for the creation of a chatbot. Taking into account that it is difficult to apply any algorithm in text, we use a technique called “Word Embedding”, which converts a text into numbers in order to run text processing. Specifically, “Word2Vec” Word Embedding technique was applied. AlexNet, LeNet5, ResNet and VGGNet CNN architectures were utilised. These architectures were compared for their accuracy, f1 score, training time and execution time. The results obtained highlighted that there were significant differences in the performance of the architectures applied. The most preferable architecture of our study was LeNet-5 having the best accuracy com...
In this paper we consider the decentralized load-frequency control (LFC) of a two-area power syst... more In this paper we consider the decentralized load-frequency control (LFC) of a two-area power system. The model of the power system is determined, and is viewed as an interconnected system (A, B d), for which the methods of the decentralized control are applied; these are based on the intercontrollability matrix D(s), its kernel U(s), and the equivalent system {M(s), I 2 } in the operator domain. Based on this, a decentralized control via linear programming methods, and with decentralized optimization techniques is determined. Several responses are given and compared.
2021 International Symposium on Performance Evaluation of Computer and Telecommunication Systems (SPECTS), 2021
Mobility management is a key function of modern wireless networks. Specifically, in vehicular env... more Mobility management is a key function of modern wireless networks. Specifically, in vehicular environments which are characterized by high mobility, networks must be able to provide a stable, uninterrupted connection to the vehicles to guarantee the continuity of their services. In this paper, the Proxy Mobile IPv6 (PMIPv6) as well as its enhanced schemes suggested by the research literature are studied, while at the same time the architecture of the 5G Core (5GC) network is described. Subsequently, a novel handover (HO) scheme is proposed for supporting Vehicle to Infrastructure (V2I) communications. The proposed scheme is based on the Fast Proxy Mobile IPv6 (FPMIPv6) protocol using the functionalities of the 5GC network and applies signaling enhancements and transient binding to improve the route of data packets to the mobile node (MN), aiming at the optimization of both Predictive and Reactive HOs. Evaluation results shows that the proposed scheme outperforms the FMIPv6 protocol in terms of HO delay, HO cost and packet loss.
A large part of information systems security approaches is technical in nature with less consider... more A large part of information systems security approaches is technical in nature with less consideration on people and organizational issues. To this end, there is a need to investigate other means of managing information systems security since most information systems security approaches although valuable they focus on technical oriented solutions, e.g. checklists, risk analysis, evaluation methods, and ignore the social aspects of risks and the informal structures of organizations. This research adopts a psychological-organizational point of view to information systems security by investigating the role and application of goals to informal structured organizations in the banking industry. The ultimate scope of this research is to investigate the importance of having an efficient goal setting structure in the context of information systems security in banking. The research contributes to interpretive information systems with the study of goal setting in a security management context.
2017 IEEE International Conference on Environment and Electrical Engineering and 2017 IEEE Industrial and Commercial Power Systems Europe (EEEIC / I&CPS Europe), 2017
Day-ahead peak load forecasting is an essential tool for generation units scheduling, unit commit... more Day-ahead peak load forecasting is an essential tool for generation units scheduling, unit commitment and generally, in power systems operation in short-term horizon. The scope of the present study is to develop a robust peak load forecasting model for the power system of Greece. The peak load series is decomposed via the Discrete Wavelet Transform (DWT) into low-frequency and high-frequency subseries in the wavelet domain. For each subseries the Support Vector Regression (SVR) model is trained and applied. The final peak load series is obtained by the inverse DWT. The proposed approach corresponds to low execution time and robust performance and thus, can be a valuable tool for utilities, systems operators and others.
While precision agriculture has been present for many years and lately massively spread through t... more While precision agriculture has been present for many years and lately massively spread through the agricultural and scientific community, little to nothing has been published for smart farming and agriculture in aromatic and herbal plants. In this article we search and review publications regarding aromatic plants’ crop management, the use of state of the art techniques while recording most common UAVs, special thermal and multispectral cameras for the raw data acquisition and aerial imagery post processing software used. We also discuss common methodologies and indices used for this specific segment of agriculture and point out the hidden potential of more efficient, in many ways, crop management in the use of UAVs.
Energies, 2017
Load profiling refers to a procedure that leads to the formulation of daily load curves and consu... more Load profiling refers to a procedure that leads to the formulation of daily load curves and consumer classes regarding the similarity of the curve shapes. This procedure incorporates a set of unsupervised machine learning algorithms. While many crisp clustering algorithms have been proposed for grouping load curves into clusters, only one soft clustering algorithm is utilized for the aforementioned purpose, namely the Fuzzy C-Means (FCM) algorithm. Since the benefits of soft clustering are demonstrated in a variety of applications, the potential of introducing a novel modification of the FCM in the electricity consumer clustering process is examined. Additionally, this paper proposes a novel Demand Side Management (DSM) strategy for load management of consumers that are eligible for the implementation of Real-Time Pricing (RTP) schemes. The DSM strategy is formulated as a constrained optimization problem that can be easily solved and therefore, making it a useful tool for retailers' decision-making framework in competitive electricity markets.
Proceedings of the 3rd Wseas International Conference on Engineering Mechanics Structures Engineering Geology, Jul 22, 2010
Brown coal is considered to be a competitive primary energy source for power generation in parts ... more Brown coal is considered to be a competitive primary energy source for power generation in parts of Central and Eastern Europe due to the economically recoverable reserves of this fuel in these regions. Specifically for Greece lignites is the main fuel and contributes at 60 % in the production of electric energy. On the other side, it is well known that coal brown contains significant amounts of moisture whish decreases the overall plant thermal efficiency due to the increased flu gas thermal loses. In order to keep the competitive edge of brown coal, an improvement of the power plant efficiency is required. In the previous paper a computing program was developed for the brown coal fluidized bed calculation in a matlab code. Model studies of fluidized bed show the best parametric a brown coal fluidized bed should have in order to dry the Greek lignite.
Technical education is, by definition, a field that requires hands-on practice and experience by ... more Technical education is, by definition, a field that requires hands-on practice and experience by the student. When it comes to distant learning, technical education suffers from lack of such practical study, given the fact that e-learning is based on theoretical material being provided remotely to the student. This article presents the idea of assisting technical education that is provided remotely,
ABSTRACT A variety of labels are used in industry in order to inform the consumers about the prod... more ABSTRACT A variety of labels are used in industry in order to inform the consumers about the product itself and comply with certain regulation demands. In addition, several graphic designs are used for creating a marketing advantage and increase the likelihood of a product/package purchase. Designers have the opportunity to influence attitudes and aspirations, aiming to achieve consumer awareness and behaviour in line with life cycle thinking. The proposed Green Label is designed in a way that results in an effective and understandable way of communicating environmental impact information to the customer in a simple and pictorial way. Therefore, it forms the basis for a marketing advantage policy making and innovation.
2011 IEEE Trondheim PowerTech, 2011
... they will have to build essentially a new dc grid and install the expensive SIMs, and ✓ it ..... more ... they will have to build essentially a new dc grid and install the expensive SIMs, and ✓ it ... The lowest level of the grid is the microgrid that is controlled by each SIM, where for ... an important disadvantage of this topology, since it is well-known that the operation of microgrids is strictly ...
Procedia Technology, 2013
The objective of this paper is the design and development of an autonomous vehicle which would be... more The objective of this paper is the design and development of an autonomous vehicle which would be able to harvest saffron flowers unsupervised. This vehicle will be able to collect the flowers of the saffron unharmed. The time for the harvest isn't more than the time needed by a human to accomplish the same task. Moreover, this procedure must be more cost effective compared to the same task accomplished by a human. We also take under consideration that the plant appears to be very sensitive to the fluctuation of pH and can be chemically destroyed in the presence of oxidizing factors and in an ionized environment. It is also very sensitive to the atmosphere's humidity (due to its trichoid stamen) however it seems to be resistant to heat. Generally, the vehicle will be able to accomplish all the operations without the need of human supervision.
International Journal of Information Technology Project Management, 2011
This research investigates the role of project commitment in the context of information systems s... more This research investigates the role of project commitment in the context of information systems security. In doing so, the research adopts a psychological point of view by exploring and discussing the concept of project commitment in setting information security goals. Information security can be viewed as the efficient control of uncertainty arising from malicious acts intended to exploit valuable assets, and in the context of information systems the valuable assets under consideration are data. Data were collected by using an interpretive approach through in-depth interviews and observation within a single case study in Greece. The contribution of this research to interpretive information-systems consists of the study of project commitment and goal theory in an information security-management context, and its grounding within an interpretive epistemology. Ultimately, this research promotes an interdisciplinary and interorganizational theory that fosters a dialogue transcending ind...
Innovations, 2004
Ruben Cabello, Lab.Microelectrónica. EPS, Universidad Autonoma, 28049 Madrid, Spain Ivan Gonzalez... more Ruben Cabello, Lab.Microelectrónica. EPS, Universidad Autonoma, 28049 Madrid, Spain Ivan Gonzalez, Lab.Microelectrónica. EPS, Universidad Autonoma, 28049 Madrid, Spain Francisco Gomez-Arribas,Lab.Microelectrónica. EPS, Universidad Autonoma, 28049 Madrid, Spain ...
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Papers by nikolaos Asimopoulos