Višnja Križanović

Dr. Višnja Križanović

orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

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

Representative Publications

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12 July 2023 in Sensors
Verified
Journal Article
Open access
PDF file
Višnja KrižanovićVišnja Križanović
Višnja Križanović
Krešimir GrgićKrešimir Grgić
Krešimir Grgić
JSJosip Spišić
Josip Spišić
Drago ŽagarDrago Žagar
Drago Žagar
Sensor networks, as a special subtype of wireless networks, consist of sets of wirelessly connected sensor nodes often placed in hard-to-reach environments. Therefore, it is expected that sensor nodes will not be powered from the power grid. Instead, sensor nodes have their own power sources, the replacement of which is often impractical and requires additional costs, so it is necessary to ensure minimum energy consumption. For that reason, the energy efficiency of wireless sensor networks used for monitoring environmental parameters is essential, especially in remote networking scenarios. In this paper, an overview of the latest research progress on wireless sensor networks based on LoRa was provided. Furthermore, analyses of energy consumption of sensor nodes used in agriculture to observe environmental parameters were conducted using the results of real measurements in the field, as well as simulations carried out based on collected data about real equipment. Optimization methods of energy consumption, in terms of choosing the appropriate data collection processes from the conducted field measurements, as well as the settings of network radio parameters imitating real conditions used in conducted simulations were highlighted. In the analyses, special emphasis was placed on choosing the optimal packet size. Unlike in other papers analyzing energy efficiency of LoRa communication, in this paper, it was proven that the adjustment of the transmission speed to the actual size of the packet is important for better energy efficiency of communication and that it can reduce energy consumption considerably. Moreover, in the paper, the contents of a packet that can be used in precision agriculture is suggested in order to prove that the 6-bit packet is sufficient for energy-efficient collection of parameters from the environment, in contrast to the 11-bit packets used in standard commercially available equipment.

18 July 2016 in Journal of Sensors
Verified
Journal Article
Open access
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Krešimir GrgićKrešimir Grgić
Krešimir Grgić
DZDrago Zagar
Drago Zagar
Višnja KrižanovićVišnja Križanović
Višnja Križanović
The trend of implementing the IPv6 into wireless sensor networks (WSNs) has recently occurred as a consequence of a tendency of their integration with other types of IP-based networks. The paper deals with the security aspects of these IPv6-based WSNs. A brief analysis of security threats and attacks which are present in the IPv6-based WSN is given. The solution to an adaptive distributed system for malicious node detection in the IPv6-based WSN is proposed. The proposed intrusion detection system is based on distributed algorithms and a collective decision-making process. It introduces an innovative concept of probability estimation for malicious behaviour of sensor nodes. The proposed system is implemented and tested through several different scenarios in three different network topologies. Finally, the performed analysis showed that the proposed system is energy efficient and has a good capability to detect malicious nodes.

10 July 2017 in Universal Access in the Information Society
Verified
Journal Article
Open access
PDF file
Višnja KrižanovićVišnja Križanović
Višnja Križanović
DZDrago Zagar
Drago Zagar
Krešimir GrgićKrešimir Grgić
Krešimir Grgić
Broadband solutions, i.e., broadband technologies and services, offer users numerous benefits. However, inequalities related to the levels of broadband solutions’ deployment and adoption between rural and urban areas, i.e., the digital divide, remain a consequential problem worldwide. To reduce the digital divide, the issues related to the deployment and usage of broadband solutions in rural areas are analysed in this paper. To define optimal strategies for the deployment and adoption of rural broadband solutions, the application of an extended techno-economic assessment process is considered. Therefore, an additional framework that extends the structure of standard techno-economic models is proposed, and its detailed overview is given. Within the framework, the regression analyses of factors relevant to broadband solutions deployment and adoption in rural areas are defined. The results of conducted analyses are used in the standard techno-economic modelling process. Finally, the efficiency of framework usage in techno-economic assessment process and in finding optimal broadband solutions is demonstrated for a case study rural scenario.

14 June 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
Višnja KrižanovićVišnja Križanović
Višnja Križanović
Krešimir GrgićKrešimir Grgić
Krešimir Grgić
JSJosip Spišić
Josip Spišić
Drago ŽagarDrago Žagar
Drago Žagar
Sensor networks, as a special subtype of wireless networks, consist of sets of wirelessly connected sensor nodes often placed in hard-to-reach environments. Therefore, it is expected that sensor nodes will not be powered from the power grid. Instead, sensor nodes have their own power sources, the replacement of which is often impractical and requires additional costs, so it is necessary to ensure minimum energy consumption. For that reason, the energy efficiency of wireless sensor networks used for monitoring environmental parameters is essential, especially in remote networking scenarios. In this paper, an overview of the latest research progress on wireless sensor networks based on LoRa was provided. Furthermore, the analyses of the energy consumption of sensor nodes used in agriculture to observe environmental parameters were carried out. Optimization methods of energy consumption, in terms of choosing the appropriate data collection processes, as well as the settings of wireless network radio parameters were suggested. In the conducted analyses, special emphasis was placed on choosing the optimal package size. In this paper, it was proven that the adjustment of the transmission speed to the actual size of the packet is important for better energy efficiency of communication.

13 February 2017 in Security and Communication Networks
Verified
Journal Article
Open access
PDF file
MKMirko Kohler
Mirko Kohler
ILIvica Lukić
Ivica Lukić
Višnja KrižanovićVišnja Križanović
Višnja Križanović
In modern communication systems, one of the most challenging tasks involves the implementation of adequate methods for successful and secure transfer of confidential digital information over an unsecured communication channel. Many encryption algorithms have been developed for protection of confidential information. However, over time, flaws have been discovered even with the most sophisticated encryption algorithms. Each encryption algorithm can be decrypted within sufficient time and with sufficient resources. The possibility of decryption has increased with the development of computer technology since available computer speeds enable the decryption process based on the exhaustive data search. This has led to the development of steganography, a science which attempts to hide the very existence of confidential information. However, the stenography also has its disadvantages, listed in the paper. Hence, a new method which combines the favourable properties of cryptography based on substitution encryption and stenography is analysed in the paper. The ability of hiding the existence of confidential information comes from steganography and its encryption using a coding table makes its content undecipherable. This synergy greatly improves protection of confidential information.

1 October 2018 in Advanced Engineering Informatics
Verified
Journal Article
Open access
Višnja KrižanovićVišnja Križanović
Višnja Križanović
DŽDrago Žagar
Drago Žagar
KGKrešimir Grgić
Krešimir Grgić
MVMario Vranjes
Mario Vranjes