Telfor Journal Vol.15 No.2 (2023)
Content
Editorial 
Editor-in-Chief:
Prof. Dr Aleksandar Nešković
Quadratic Fitting Model in No-Reference Image Quality Assessment
A. Gavrovska, D. Dujković, A. Samčović, Y. Golub, and V. Starovoitov- Topic:
- Multimedia
- Abstract
- The perceptual quality of image is affected by distortions during compression, delivery and storage. Distortions also impact automatic image quality assessment (IQA) that needs to be highly correlated with subjective scores. In the absence of reference, which is a typical scenario in practice, no-reference (NR) metrics are necessary for quality measurements. Recently such methods are proposed, and they employ natural scene statistics (NSS). The experimental analysis performed in this paper takes into consideration two fitting or regression models of several NR-IQA metrics relying on different distortion types. The results show quadratic model as promising for making relations in terms of difference mean opinion score and Shannon entropy.
- Keywords
- Image Quality Assessment, no-reference, fitting model, correlation, subjective score, Shannon entropy.
- Full Text
- Quadratic Fitting Model in No-Reference Image Quality Assessment
- Page(s)
- 32-37
- Doi
- 10.5937/telfor2302032G
Centralized Controlling of Distributed PV Systems using Cloud and IoT Technologies
I. Vujović, M. Koprivica, and Ž. Đurišić- Topic:
- IoT
- Abstract
- Usage of electrical energy obtained from renewable sources is rapidly increasing. Distributed solar systems will be widely used. The photovoltaic (PV) systems can be used to produce active and reactive power or to compensate reactive power. This paper proposes a solution for monitoring and management of distributed PV systems from the integrated center. The main parts of the system are a cloud infrastructure at the Data Center and Internet of Things (IoT) devices at distributed sites. Also, networks that are used for communication between main parts are an important piece of the proposed solution. While IoT devices continuously send information about electrical parameters of the system and environmental conditions, the inverter, as a part of the PV system, can be controlled by influencing the Maximum Power Point Tracking (MPPT) algorithm operation and inverter functionality.
- Keywords
- distributed PV system, MPPT algorithm, cloud, Internet of Things, network.
- Full Text
- Centralized Controlling of Distributed PV Systems using Cloud and IoT Technologies
- Page(s)
- 38-43
- Doi
- 10.5937/telfor2302038V
Developing Multilingual Learning Application to Arabic Elementary Learning
Taufik, H. S. Zainiyati, A. T. Wibowo, A. Bramantoro, and Y. Farida
- Topic:
- Speech Processing
- Abstract
- Nowadays, Learning Arabic is perceived as drab by students, with 2.4% finding it very drab, 25.3% finding it drab, and 34.9% finding it quite drab. This research is a development of the MLATS ARABIC for easy Arabic language learning. The functional testing showed a 100% success rate for all 7 test cases, and the application performed well on five different computer browsers. The user satisfaction survey yielded a 95% average satisfaction rate for each indicator.
- Keywords
- Arabic language learning, MLATS ARABIC, user satisfaction.
- Full Text
- Developing Multilingual Learning Application to Arabic Elementary Learning
- Page(s)
- 44-49
- Doi
- 10.5937/telfor2302044T
Method of Two-Factor Authentication of Electronic Documents Using Enhanced Encrypted Non-Certified Digital Signature with the Use of Security Token with Biometric Data
T. A. Burganova, D. R. Fakhreeva, and N. N. Fakhreev- Topic:
- Software Tools and Applications
- Abstract
- The purpose of this study is to develop a method for two-factor authentication of electronic documents using an enhanced encrypted non-certified digital signature with the use of a security token with biometric data (fingerprint image). In order to achieve the goal, the method of comparative analysis was used. Existing algorithms for the electronic signature operation were studied. The method of multi-factor authentication of an electronic signature using biometric data has been studied in detail. Biometric data included: a handwritten password, an autograph, typing biometrics when typing a pass phrase, a facial image, typing biometrics when typing a free text. An external storage medium with a biometric authentication method based on a fingerprint image was also studied. Information on this media was accessed by scanning a fingerprint image. After conducting a comparative analysis and studying in detail these methods, a method for two-factor authentication of an electronic signature using a security token with biometric data was developed.
- Keywords
- two-factor authentication, digital signature, security token, fingerprint image, algorithm.
- Full Text
- Method of Two-Factor Authentication of Electronic Documents Using Enhanced Encrypted Non-Certified Digital Signature with the Use of Security Token with Biometric Data
- Page(s)
- 50-55
- Doi
- 10.5937/telfor2302050B
Call Rating based on Objective Data Extraction
E. Avdagić-Golub, N. Goran, B. Karahodža, M. Begović, and B. Memić- Topic:
- Telecommunications Services
- Abstract
- Interaction channels are special opportunities to improve customer satisfaction by offering a consistent problem-solving experience. Contact center employees are the link between the company and the customer. They are responsible for maintaining an appropriate relationship between the company and the customer. So, they are personally responsible for the customer experience. In this paper, we present an objective evaluation method for evaluating customer-agent interaction, i.e., evaluating the effectiveness of the realization of customer requests from calls. The evaluation method is automatic and does not depend on the relationship between the call center manager and the employees. The motivation for evaluating calls stems from the key performance characteristics of a contact center, of which we particularly emphasize service time, first call resolution, handling time, and others.
- Keywords
- contact center, agent, call rating, call routing
- Full Text
- Call Rating based on Objective Data Extraction
- Page(s)
- 56-62
- Doi
- 10.5937/telfor2302056A
The TELFOR Journal appreciates the support received from the reviewers. The following is the alphabetic list of the reviewers who have submitted one or more reviews for the current volume of the TELFOR Journal.
Marko Barjaktarović, School of Electrical Engineering, University of Belgrade, Serbia; Milana Bojanić, Faculty of Technical Sciences, University of Novi Sad, Serbia; Živko Bojović, Faculty of Technical Sciences, University of Novi Sad, Serbia; Urban Burnik, Univesity of Ljubljana, Faculty of Electrical Engineering, Slovenia; Goran Đorđević, Faculty of Electronic Engineering, University of Niš, Serbia; Dejan Drajić, School of Electrical Engineering, University of Belgrade, Serbia; Radivoje Đurić, School of Electrical Engineering, University of Belgrade, Serbia; Marija Malnar, Faculty of Transport and Traffic Engineering, University of Belgrade, Serbia; Goran Marković, School of Electrical Engineering, University of Belgrade, Serbia; Dejan Milić, Faculty of Electronic Engineering, University of Niš, Serbia; Nenad Jevtić, Faculty of Transport and Traffic Engineering, University of Belgrade, Serbia; Veljko Papić, School of Electrical Engineering, University of Belgrade, Serbia; Milorad Paskaš, School of Information and Communication Technologies, Academy of Technical and Art Applied Studies Belgrade, Serbia; Aleksandra Pavlović, School of Electrical and Computer Engineering, Academy of Technical and Art Applied Studies Belgrade, Serbia; Andreja Samčović, Faculty of Transport and Traffic Engineering, University of Belgrade, Serbia; Tomislav Šekara, School of Electrical Engineering, University of Belgrade, Serbia; Pavle Vuletić, School of Electrical Engineering, University of Belgrade, Serbia; Marija Zajeganović, School of Information and Communication Technologies, Academy of Technical and Art Applied Studies Belgrade, Serbia; Goran Zajić, School of Information and Communication Technologies, Academy of Technical and Art Applied Studies Belgrade, Serbia; Amela Zeković, School of Electrical and Computer Engineering, Academy of Technical and Art Applied Studies Belgrade, Serbia;