Preface to the International Scientific Conference on Communications, Information, Electronic and Energy Systems (CIEES’2021)

The International Scientific Conference on Communications, Information, Electronic and Energy Systems (CIEES’2021) was held virtually in Ruse, Bulgaria from 25 to 27 November, 2021. The CIEES’2021 was organized by the Association CIEES with the following partners: University of Ruse (Bulgaria), Politehnica University of Bucharest (Romania), the Union of Scientists in Ruse (Bulgaria) and Encon Services Ltd (Bulgaria). In light of the current situation related to the coronavirus (COVID-19) and regarding to the internal government regulations from the Bulgarian Ministry of Health, the Organizing Committee took the decision to turn CIEES’2021 in a virtual format – online conference on the same period. The goal of the CIEES’2021 conference is to provide an international forum for researchers, academics, people in industry, and students to address recent research results and to present and discuss their ideas, theories, technologies, systems, tools, applications, work in progress and experiences on all theoretical and practical issues arising in telecommunications, electronics, signal processing and applications, information technologies and energy. List of CIEES 2021 Organizing Committee, CIEES 2021 International Scientific Committee are avilable in the pdf.

In light of the current situation related to the coronavirus  and regarding to the internal government regulations from the Bulgarian Ministry of Health, the Organizing Committee took the decision to turn CIEES'2021 in a virtual format -online conference on the same period.
The goal of the CIEES'2021 conference is to provide an international forum for researchers, academics, people in industry, and students to address recent research results and to present and discuss their ideas, theories, technologies, systems, tools, applications, work in progress and experiences on all theoretical and practical issues arising in telecommunications, electronics, signal processing and applications, information technologies and energy.
The technical program of this year's edition of the conference consists of three distinguished keynotes by world-renowned experts with their lectures as follows: Prof. Stefan Ditchev DSc, University of Food Technologies -Plovdiv, Bulgaria, the title of the lecture "The heat pump systems -an option for energy efficiency and innovation of technologies"; Assist. Prof. Dr. Frank Grabner, IMG Electronic & Power Systems GmbH, Nordhausen, Germany, the title of the lecture "New EMC effects with multi-layered type of EM shield"; Prof. Dr. Felipe L. Peñaranda-Foix, Universidad Politécnica de Valencia (UPV), Valencia, Spain, the title of the lecture "Material electromagnetic characterization".
During the online conference, were used the Zoom Meeting platform for the opening ceremony, all conference sessions, and meetings. In advance, the Conference Organizing Committee of CIEES 2021 organized test sessions for participants, Conference chairs, and plenary lecturers. All authors prepared a video presentation of up to 12 minutes that was played on stream with authors IOP Publishing doi:10.1088/1757-899X/1216/1/011001 2 participating in the discussion during the session. All of the video presentations are available on the conference YouTube© channel.
The conference programme consists 3 special sessions and 7 technical sessions. The time slot for presentation and Q&A was 15 minutes. Questions were asked in the chat section of the zoom channel or by raised hand when the video presentation is finished. All Q&A were made face-toface in the Zoom channel, between the CIEES Host (technical moderator), Session Chair, and participants.
Among the submitted manuscripts, 20 full papers passed the review process for publication in IOP Conference Series: Materials Science and Engineering. The review process was conducted according to the review policy of the IOP conference series, involving national and international reviewers -each paper was reviewed by two reviewers. During the discussion phase, International Scientific Committee members and the Programme Committee members discussed the reviews in detail. The rebuttals from the authors were also seriously considered. For consistency across tracks, final decisions on papers were made at the face-to-face Programme Committee meeting between the Organizing Committee chairs and the Programme Committee chairs.
Finally, we are grateful to all members of the International Scientific Committee, for providing insightful guidelines and support in preparing and organizing the conference, and for the highly professional work done on all aspects of the local organization of the Conference.
We thank all authors and participants for their contributions.
CIEES is an annual conference. More information about the conference and the forthcoming events, please visit the website: http://ciees.eu.