Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
Browse
3 results
Search Results
Conference Object Citation - WoS: 3Citation - Scopus: 4Seamless Mobile Data Offloading in Heterogeneous Wireless Networks Based on IEEE 802.21 and User Experience(Institute of Electrical and Electronics Engineers Inc., 2014-04) Tüzünkan, Firat A.; Güngör, Vehbi Çağrı; Zeydan, Engin; Ileri, Ömer; Ergüt, SalihThe increase on smartphone usage has brought the burden of data traffic with it. Operators are looking for cost-effective solutions to overcome the problem of 3G infrastructure for high contention traffic scenarios. Several schemes were offered to save the moment, and they brought some extra costs including deploying femtocell or WiMax, LTE, LTE-Advanced systems along with their expensive equipment. On the other hand, operators are expanding their networks with 802.11 technologies such that they can exploit the free-band communication. Meaning the data traffic can handover between WLAN and UMTS interchangeably. By using NS-2 simulator, we implemented IEEE 802.21 WG's Media Independent Handover (MIH) module by combining with Channel Quality Indicator (CQI) values collected from user equipment (UE) and observed a recovered throughput for both medium. We found that there is a tradeoff among energy efficiency, delay tolerance and cost. Furthermore, in this study, we integrated a Quality of Experience (QoE) metric during real-time handover decision process so that with this type of collaborative solution, an operator will be unique in terms of user happiness and heterogeneous network management. © 2021 Elsevier B.V., All rights reserved.Book Part Citation - Scopus: 54Energy Harvesting and Battery Technologies for Powering Wireless Sensor Networks(Elsevier Inc., 2016) Tuna, Gürkan; Güngör, Vehbi ÇağrıDue to the advances in wireless sensor networks (WSNs), factory and plant process automation systems are being reinvented. WSN-based industrial applications often cost much less than wired networks in both the short and long terms; automation engineers are empowering existing solutions with the new capabilities of WSNs. On the other hand, since industrial wireless sensor networks (IWSNs) consist of thousands of nodes, the problem of powering the nodes is critical. Power to the nodes is usually provided through primary batteries and this necessitates replacement when the batteries are depleted. However, the replacement may not be cost-effective or even feasible in most industrial applications.Though advancements in integrated circuit technologies help in saving more energy by leading to lower energy consumption levels, they do not eliminate the use of battery power. In this regard, energy harvesting technologies play a key role in extending the battery lifetime of the nodes. Wireless sensor nodes within industrial plants can operate from energy harvested from available energy sources such as heat, mechanical motion or vibration, indoor lighting, electromagnetic fields, and air flow. In this chapter, a review of existing energy storage technologies and various energy-harvesting techniques is given. The chapter then discusses open research issues in these topics. © 2020 Elsevier B.V., All rights reserved.Conference Object Citation - Scopus: 2Comparative Performance Analysis of Ethereum and Optimism Smart Contracts in Health Insurance(Institute of Electrical and Electronics Engineers Inc., 2024-10-26) Dedeturk, Beyhan Adanur; Dedeturk, Bilge KaganOne type of insurance that people purchase to cover unexpected medical expenses is health insurance. In exchange for premium payments, the insurance company may cover a portion of the insured person's medical expenses, such as prescription medications, hospital stays, and doctor visits. This method makes access to healthcare easier and less expensive. Health insurance systems do, however, have a number of issues, including fair insurance premium calculation, automation, data verification, privacy and security, and cost effectiveness. These issues are starting to be addressed by blockchain technology, particularly with the help of smart contracts. Using a comparison analysis between Ethereum and Optimism smart contracts, this paper demonstrates the performance of health insurance. Simulation of these BC technologies was carried out both on the Sepolia testnet and using Alchemy. Tools and metrics provided to monitor the performance of Alchemy applications, detect errors, and analyze user interactions were used in the measurements. While Ethereum's well-established ecosystem offers robust support for smart contracts, Optimism distinguishes itself as a scalable substitute that delivers quicker transaction speeds and more affordable options. According to the analysis results, the advantages and disadvantages of Ethereum and Optimism are highlighted when it comes to health insurance. © 2025 Elsevier B.V., All rights reserved.