Panagiotis Karampelas

Dr. Panagiotis Karampelas

orcid

Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
1 March 2010 in Electric Power Systems Research
Verified
Journal Article
Closed access
Stylianos PappasStylianos Pappas
Stylianos Pappas
LEL. Ekonomou
L. Ekonomou
PKPanagiotis Karampelas
Panagiotis Karampelas
DKD.C. Karamousantas
D.C. Karamousantas
Sokratis KatsikasSokratis Katsikas
Sokratis Katsikas
PSP.D. Skafidas
P.D. Skafidas

1 October 2011
Verified
Conference Paper
Closed access
PKPanagiotis Kalagiakos
Panagiotis Kalagiakos
PKPanagiotis Karampelas
Panagiotis Karampelas
Cloud Computing is evolving as a key technology for sharing resources. Grid Computing, distributed computing, parallel computing and virtualization technologies define the shape of a new era. Traditional distance learning systems lack reusability, portability and interoperability. This paper sees cloud computing ecosystem as a new opportunity in designing cloud computing educational platforms where learning actors can reuse learning resources handled by cloud educational operating systems. To enhance learning objects portability and interoperability not only cloud computing API standards should be advocated by the key cloud providers but also learning resources standards should be defined by the Open Cloud Computing Education Federation as proposed by this paper.

5 April 2016 in Applied Intelligence
Verified
Journal Article
Closed access
PDF file
KXKonstantinos F. Xylogiannopoulos
Konstantinos F. Xylogiannopoulos
PKPanagiotis Karampelas
Panagiotis Karampelas
RAReda Alhajj
Reda Alhajj

1 September 2021 in BMC Public Health
Verified
Journal Article
Open access
PDF file
KXKonstantinos F. Xylogiannopoulos
Konstantinos F. Xylogiannopoulos
PKPanagiotis Karampelas
Panagiotis Karampelas
RAReda Alhajj
Reda Alhajj
Background: The first half of 2020 has been marked as the era of COVID-19 pandemic which affected the world globally in almost every aspect of the daily life from societal to economical. To prevent the spread of COVID-19, countries have implemented diverse policies regarding Non-Pharmaceutical Intervention (NPI) measures. This is because in the first stage countries had limited knowledge about the virus and its contagiousness. Also, there was no effective medication or vaccines. This paper studies the effectiveness of the implemented policies and measures against the deaths attributed to the virus between January and May 2020. Methods: Data from the European Centre for Disease Prevention and Control regarding the identified cases and deaths of COVID-19 from 48 countries have been used. Additionally, data concerning the NPI measures related policies implemented by the 48 countries and the capacity of their health care systems was collected manually from their national gazettes and official institutes. Data mining, time series analysis, pattern detection, machine learning, clustering methods and visual analytics techniques have been applied to analyze the collected data and discover possible relationships between the implemented NPIs and COVID-19 spread and mortality. Further, we recorded and analyzed the responses of the countries against COVID-19 pandemic, mainly in urban areas which are over-populated and accordingly COVID-19 has the potential to spread easier among humans. Results: The data mining and clustering analysis of the collected data showed that the implementation of the NPI measures before the first death case seems to be very effective in controlling the spread of the disease. In other words, delaying the implementation of the NPI measures to after the first death case has practically little effect on limiting the spread of the disease. The success of implementing the NPI measures further depends on the way each government monitored their application. Countries with stricter policing of the measures seems to be more effective in controlling the transmission of the disease. Conclusions: The conducted comparative data mining study provides insights regarding the correlation between the early implementation of the NPI measures and controlling COVID-19 contagiousness and mortality. We reported a number of useful observations that could be very helpful to the decision makers or epidemiologists regarding the rapid implementation and monitoring of the NPI measures in case of a future wave of COVID-19 or to deal with other unknown infectious pandemics. Regardless, after the first wave of COVID-19, most countries have decided to lift the restrictions and return to normal. This has resulted in a severe second wave in some countries, a situation which requires re-evaluating the whole process and inspiring lessons for the future.

23 August 2014 in Applied Intelligence
Verified
Journal Article
Open access
PDF file
KXKonstantinos F. Xylogiannopoulos
Konstantinos F. Xylogiannopoulos
PKPanagiotis Karampelas
Panagiotis Karampelas
RAReda Alhajj
Reda Alhajj
Suffix arrays form a powerful data structure for pattern detection and matching. In a previous work, we presented a novel algorithm (COV) which is the only algorithm that allows the detection of all repeated patterns in a time series by using the actual suffix array. However, the requirements for storing the actual suffix strings even on external media makes the use of suffix arrays impossible for very large time series. We have already proved that using the concept of Longest Expected Repeated Pattern (LERP) allows the actual suffices to be stored in linear capacity O(n) on external media. The repeated pattern detection using LERP has analogous time complexity, and thus makes the analysis of large time series feasible and limited only to the size of the external media and not memory. Yet, there are cases when hardware limitations might be an obstacle for the analysis of very larger time series of size comparable to hard disk capacity. With the Moving LERP (MLERP) method introduced in this paper, it is possible to analyze very large time series (of size tens or hundreds thousands times larger than what the LERP can analyze) by maximal utilization of the available hardware. Further, when empirical knowledge related to the distribution of repeated pattern’s length is available, the proposed method (MLERP) can achieve better time performance compared to the standard LERP method and definitely much better than using any other pattern matching algorithm and applying brute force techniques which are unfeasible in logical (human) time frame. Thus, we may argue that MLERP is a very useful tool for detecting all repeated patterns in a time series regardless of its size and hardware limitations.

1 December 2008 in Journal of Zhejiang University-SCIENCE A
Verified
Journal Article
Closed access
PDF file
Stylianos PappasStylianos Pappas
Stylianos Pappas
Lambros EkonomouLambros Ekonomou
Lambros Ekonomou
VMV. C. Moussas
V. C. Moussas
PKPanagiotis Karampelas
Panagiotis Karampelas
Sokratis KatsikasSokratis Katsikas
Sokratis Katsikas
Designers are required to plan for future expansion and also to estimate the grid’s future utilization. This means that an effective modeling and forecasting technique, which will use efficiently the...