Sürdürülebilir Kalkınma Amaçları
Yayınlar
- ArticleAçık Erişim2019A Study on Room-Level Accuracy of Wi-Fi Fingerprinting-Based Indoor Localization Systems
Dalkılıç, Feriştah; Çabuk, Umut Can; Dagdeviren, Orhan
Global positioning system and other outdoor positioning mechanisms are already subject to comprehensiveresearch and development for almost half a century. Conversely, indoor positioning services became a hottopic in the last decade. Since GPS (and. other outdoor solutions) do not work reliably in most indoorenvironments, researchers and developers are working on accurate positioning solutions, especially tailoredfor indoor places. However; due to walls, furniture, people and other obstacles, absolute location estimationis very hard and expensive to achieve in indoor places. In addition, accuracy needs depend on the scenarioand application. In this study, we have studied the feasibility of room-level location detection in home andoffice environments. We have focused on examining the quality of room-wise detection accuracy of thefingerprinting method that is applied along with standard Wi-Fi radio infrastructure. We have conductedexperiments in a multi-storey office building made of concrete and aerated concrete bricks with manyrooms, in which it is significantly hard to accurately estimate the correct place of a thing, using radio signals.To the best of our knowledge, our paper is the first study that investigates the room-level accuracy of Wi-Fi fingerprinting-based indoor localization systems. We have found out that, it is possible to feasibly achieveroom-level detection with good accuracy, via a pre-calculated room-specific received signal strengthindicator threshold value.
RDL Kalıcı Kaydıİncele - Conference ObjectYalnız künye2019A Path Loss Analysis on LTE Radio in Eastern Market Districts
Çabuk, Umut Can; Dalkiliç, Gökhan
Radio propagation and path loss attenuation are subject to many research - even for LTE - throughout decades already. Nevertheless, smart city and Internet of Things concepts are emerging recently. Hence, new path loss studies are required to address new problems that come up with these. This study introduces eastern market districts, located in the heart of some big cities, as distinct areas with special needs. So, many widespread propagation models are analyzed and evaluated considering environmental properties. Consequently, the COST231 Walfisch-Ikegami model is found to be the best fit for the defined area type; hence, the need for the empirical measurements are eliminated. Finally, simulations and calculations are made using the model, in order to make inferences about the coverage, the capacity and the quality of an LTE network to serve smart city services to the area.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2018Gömülü Sistemler İçin Android Tabanlı Bir Mikroişlemci Programlama Yazılımı
Yiğit, Yasin; Süvari, Metin; Çabuk, Umut Can; Dağdeviren, Orhan
Gömülü sistemler belirli görevleri yerine getirmek amacıyla tasarlanıp beyaz eşya, trafik ışıkları, akıllıfabrikalar, ofis cihazları ve nesnelerin interneti gibi alanlarda kullanılır. Farklı gömülü sistemlerinin programlanmasıiçin farklı elektronik kartlar ve bilgisayar desteği gerekebilir. Böyle durumda bazı üreticilerin gömülü sistemlereyazılım yükleme işini dış sağlayıcılardan alınan hazır programlama cihazları ile yaptıkları görülmüştür. Bu cihazlardaparalel programlama imkânı olmadığından yazılım yükleme işi ancak sırayla yapılabilmektedir. Bu cihazlara firmaiçinde birçok birim aynı anda ihtiyaç duyabilir. Tüm bunlar maliyeti yükseltmekte ve performansı düşürmektedir. Diğeryandan, birçok durumda teknik servis ekipleri müşterilere giderken operasyonel nedenlerle bilgisayar taşımamaktadır.Dolayısıyla, bilgisayar kullanılmadan, tablet veya cep telefonu üzerinden gömülü sistem kartlarına yazılım yüklemeişleminin yapılması uygun bir strateji olabilir. Android işletim sistemi günümüzde akıllı telefon ve tabletlerin ötesindeyaygın bir kullanım alanına sahip olmuştur. Öyle ki, gömülü sistemler ve bunları programlamaya yarayan cihazlardadahi Android kullanılabilmektedir. Tablet ve cep telefonlarının maliyet, kullanım kolaylığı ve taşınabilirlikavantajlarından dolayı kişisel bilgisayarlara göre daha fazla kullanım alanı bulunmaktadır. Bu çalışmada Vestel BeyazEşya AŞ için, farklı ürünlere özgü farklı konsept işlemcileri destekleyen, paralel programla yapabilen ve üretimortamına-koşullarına uygun bir programlama cihazı tasarlanmış ve gerçeklenmiştir. Ayrıca, cihazın kontrol edilmesinisağlayan Windows ve Android uygulamaları da yazılmıştır. Üzerinde çalışılan gömülü sistem beyaz eşya odaklıolmasına karşın, tasarlanan sistem farklı gömülü sistemlerde de etkin olarak kullanılabilir.
RDL Kalıcı Kaydıİncele - Conference ObjectYalnız künye2018Towards secure e-voting using ethereum blockchain
Koç, Ali Kaan; Yavuz, Emre; Çabuk, Umut Can; Dalkiliç, Gökhan; Varol, A.; Karabatak, M.; Varol, C.
There is no doubt that the revolutionary concept of the blockchain, which is the underlying technology behind the famous cryptocurrency Bitcoin and its successors, is triggering the start of a new era in the Internet and the online services. While most people focus only at cryptocurrencies; in fact, many administrative operations, fintech procedures, and everyday services that can only be done offline and/or in person, can now safely be moved to the Internet as online services. What makes it a powerful tool for digitalizing everyday services is the introduction of smart contracts, as in the Ethereum platform. Smart contracts are meaningful pieces of codes, to be integrated in the blockchain and executed as scheduled in every step of blockchain updates. E-voting on the other hand, is another trending, yet critical, topic related to the online services. The blockchain with the smart contracts, emerges as a good candidate to use in developments of safer, cheaper, more secure, more transparent, and easier-to-use e-voting systems. Ethereum and its network is one of the most suitable ones, due to its consistency, widespread use, and provision of smart contracts logic. An e-voting system must be secure, as it should not allow duplicated votes and be fully transparent, while protecting the privacy of the attendees. In this work, we have implemented and tested a sample e-voting application as a smart contract for the Ethereum network using the Ethereum wallets and the Solidity language. Android platform is also considered to allow voting for people who do not have an Ethereum wallet. After an election is held, eventually, the Ethereum blockchain will hold the records of ballots and votes. Users can submit their votes via an Android device or directly from their Ethereum wallets, and these transaction requests are handled with the consensus of every single Ethereum node. This consensus creates a transparent environment for e-voting. In addition to a broad discussion about reliability and efficiency of the blockchain-based e-voting systems, our application and its test results are presented in this paper, too.
RDL Kalıcı Kaydıİncele - Conference ObjectYalnız künye2017Providing key diversity for symmetric encryption in Ad-Hoc wireless networks
Polat, Çaǧri; Yildiz, Kadir; Çabuk, Umut Can; Dalkiliç, Gökhan; Adali, E
The revolutionary network that totally changed how the humankind life, the Internet, is now evolving into the Internet of things; which is being achieved by fetching the network connectivity to legacy industrial or commercial devices, as well as everyday objects. This connectivity may be an Internet connection, where the Internet protocol and related technologies are in use. But, there are also many constrained devices, like sensors, actuators, radio frequency identification (RFID) tags and smart cards etc., which cannot handle the full-stack. These devices usually form ad-hoc networks, in which the internal data communication is made via lighter protocols, while the Internet connection is provided by anchor/gateway nodes. This structure brings ease of use, saves power and allows development of new technologies. However, privacy and security are under severe threats, much more than ever. In this paper, we propose a key diversification method, inspired from RFID smart cards, to be used in symmetric encryption within these ad-hoc networks. Thus, lightweight devices will be able to communicate securely, without exhausting their processors and wasting energy.
RDL Kalıcı Kaydıİncele - Conference ObjectYalnız künye2017An analysis of the positioning accuracy of iBeacon technology in indoor environments
Dalkiliç, Feriştah; Ankan, Emine; Çabuk, Umut Can; Gürkan, Aslihan; Adali, E
Positioning and location tracking are two major needs of the modern era; in which logistics, industry automation, smart buildings/cities and the Internet of Things concepts are trending topics and are constantly evolving. Introduction of the Global Positioning System (GPS) solved the issue well for outdoor scenarios, however, it is not a reliable solution for indoors, where satellite communication (line-of-sight in general) cannot be maintained. Additionally, there are usually many obstructions (i.e. walls), which block or distort the signals or many signal sources causing interference and noise. Thus, indoor positioning requires different and smarter approaches. iBeacon, is new device-to-device communication technology that relies on Bluetooth Low Energy. In this work, we tested accuracy of a known method used to estimate the distance between two devices communicating through the iBeacon technology. Moreover; effects of the output power, placement of the devices, existence of walls and the possible radio interference, on the accuracy of that distance estimation are investigated.
RDL Kalıcı Kaydıİncele