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Öğe Aided navigation techniques for indoor and outdoor unmanned vehicles(2012) Tuna G.; Gulez K.This paper presents design considerations of indoor and outdoor navigation techniques proposed for unmanned vehicles (UV). In this paper, we mainly investigate the use and the advantages of wireless sensor networks (WSNs) for indoor navigation, and Global Positioning System (GPS) for outdoor navigation. The system primarily uses laser range finder (LRF) measurements for indoor navigation, and is based on Extended Kalman Filter (EKF). For outdoor navigation the system uses Inertial Navigation System (INS) measurements. At periodical intervals the system integrates the measurements of an absolute sensor to improve estimations. The absolute sensor is a WSN interface for indoor navigation, and a GPS receiver for outdoor navigation. Simulation studies were conducted using Unified System for Automation and Robot Simulation (USARSim) and Player/Stage. The results of USARSim based simulations prove the advantages of integrating GPS measurements. Player/Stage based simulations show the advantages of integrating Received Signal Strength Indicator (RSSI) measurements obtained from WSN interfaces. In addition to the simulation studies, field tests with a custom-built Corobot autonomous robot platform will be realized to prove the effectiveness of the methods. © 2012 IEEE.Öğe Analysis and comparison of hash functions in terms of security and performance(IGI Global, 2023) Özer O.; Tuna G.Hash functions map data of arbitrary size to fixed-size values, though there are some that support variable length output. The values returned by a hash function are called hash values. Hash functions are used in many fields such as generation of passwords and encryption which are the building blocks of cryptology, digital signatures, data integrity control, crypto storage, and random number generation. However, some hash functions like MD5 and SHA1 are now broken. Using a weak or broken hash function can leave data vulnerable, and thus should not be used. This chapter presents definitions, structures, performances, as well as security vulnerabilities, of hash functions. © 2023, IGI Global. All rights reserved.Öğe Analysis of windows operating systems in incident response processes in cyber wars: Use of open source tools(IGI Global, 2023) Bircan M.; Tuna G.Although Windows is the most popular operating system in the world, it has many vulnerabilities, depending on its version. Due to these vulnerabilities, attackers can capture sensitive data and cause irreversible damage. Examination of these vulnerabilities and analysis of malicious codes can be done with open-source tools. Analyzing affected services in a cyber war is important to prevent the future attacks and prevent data breaches. Because, in every attack and every data breach, a trace is definitely left by the attacker(s). These traces help us identify the culprit and the magnitude of the violation committed. In this study, open-source software tools that can be used in incident response process in Windows operating systems are reviewed. As it is shown, when such tools are used appropriately and timely, they can reduce the impacts of cyber attacks and help to prevent future cyber attacks. © 2023, IGI Global. All rights reserved.Öğe Automatic positioning of mobile 3d laser scanners equipped with wireless interfaces for automatic map merging(International Multidisciplinary Scientific Geoconference, 2018) Savran D.; Tuna G.One of the most important issues in the problem of fusing partial maps without common reference frames into one large global map is requirement of manually obtaining the locations of mobile 3D laser scanners that are used to scan the environment. In this paper, we propose a novel positioning approach to obtain the locations of 3D laser scanners. The main limitation of our approach is that 3D laser scanners must be equipped with long-range wireless interfaces or off-the-shelf long-range wireless interfaces must be installed on them. Via references points (anchor nodes) on the corners of the environments, we use the measured distances and find the locations of the 3D laser scanners through multilateration technique. Although the approach proposed in this study is much easier to implement and much more cost-effective compared to the existing approaches, it is well-known that there are many challenges in real world scenarios that cannot be included in simulation environments and these challenges have impacts on the success of positioning algorithms. Therefore, the future work of this study consists of field tests using a set of 3D laser scanners and a group of anchor nodes so that the positioning accuracy of the proposed approach can be verified. © SGEM 2018.Öğe Autonomous intruder detection system using wireless networked mobile robots(2012) Tuna G.; Tasdemir C.; Gulez K.; Mumcu T.V.; Gungor V.C.Wireless networked mobile robots pursuing a common objective are envisioned to be an efficient solution for many military, industrial, commercial, and environmental applications. This paper presents the design considerations of an autonomous intruder detection system based on wireless networked robots. Specifically, three critical aspects of these systems, such as coordination and task allocation, communication, and map-based intruder detection, have been investigated and a multi-sensor fusion mechanism has been presented. Performance results show that the fusion of redundant information from different sensors can increase the accuracy of a system and reduce overall uncertainty in intruder detection applications. © 2012 IEEE.Öğe Benefits of information security awareness training against phishing attacks: A field study(IGI Global, 2023) Tufan A.; Tuna G.Phishing attacks are human-targeted attacks, and it may not always be possible to counter them with technical measures alone. By their nature, humans have a natural weakness of desiring to believe. Cyber attackers who analyze this vulnerability well have been exploiting this in order to achieve success in their respective attack targets. This study focuses on reviewing the benefits of information security awareness training against phishing attacks and aims to provide insight on this through the results of a field study. The field work was carried out in Turkey on four different scenarios on the success of information security trainings against phishing attacks. The data obtained as a result of the field study were compared with the data obtained in international studies, and the maturity of the non-regulated institutions in Turkey against phishing attacks was measured. When the data obtained as a result of the field study were compared with the international results, it was evident that the test group subject to the study exhibited a success below the international values. © 2023 by IGI Global. All rights reserved.Öğe Budget analysis for water reservoirs using an autonomous sensor-equipped mini boat(American Scientific Publishers, 2015) Tuna G.; Arkoc O.; Potirakis S.M.; Nefzi B.Water is an inescapable necessity for all forms of life on Earth. Therefore, both man-made reservoirs and natural reservoirs play critical roles for several purposes. Evaporation is an important factor that should be taken into account in the case of surface water reservoirs in hot and dry environments, since it can cause significant water loss. In order to estimate the water budgets of reservoirs, the hydrologists are typically using specifically developed computer models which take into account the effects of evaporation. An important step in this repetitive process is to provide an as accurate as possible calculation of the current water budget of reservoir under study. A novel system for the required water budget calculation is proposed in this paper, providing an automated, fast and accurate solution, requiring no human effort as it is based on an autonomous sensor-equipped mini-boat. First, the autonomous mini boat follows predefined trajectories at a reservoir and builds a bathymetric map (depth map) of it. Then, an onboard computer calculates the water budget of the reservoir. The proposed system is portable; as a result, a single system can periodically serve at several water reservoirs. Following the description of the main components of the proposed system, that is the autonomous navigation system and water budget calculation application, the performance of the navigation subsystem and the system as a whole is evaluated based on simulation studies. Copyright © 2015 American Scientific Publishers All rights reserved.Öğe Cognitive radio networks for smart grid communications: Potential applications, protocols, and research challenges(CRC Press, 2017) Kogias D.; Tuna G.; Gungor V.C.A smart grid (SG) is the next generation of power grid, where transmission, distribution, power generation, utilization, and management are fully upgraded to improve efficiency, agility, environmental friendliness, economy, security, and reliability [1-4]. It offers two-way communication between the base stations and power generation sites [2-5], and optimizes the overall system performance by taking the advantage of wireless sensor networks (WSNs) [6-13], using smart sensor devices, and implementing renewable energy solutions. Since SG consists of many different applications with different communication and quality of service (QoS) requirements, it involves heterogeneous communication technologies based on a multitier communication infrastructure. © 2016 by Taylor & Francis Group, LLC.Öğe Communication related design considerations of WSN-aided Multi-Robot SLAM(2011) Tuna G.; Gulez K.; Gungor V.C.This paper presents the communication related design considerations of Wireless Sensor Network (WSN) aided Multi-Robot Simultaneous Localization and Mapping (SLAM). In this approach, multiple robots perform WSN-aided cooperative SLAM using only range values to landmarks in the environment by measuring the Received Signal Strength Indicator (RSSI) of the received radio messages, and odometry information. The SLAM algorithm proposed in this study uses the Rao-Blackwellized Particle Filters. In addition, the inherent communication problems in WSNs, and their effects on cooperative SLAM are explained in detail and shown with the results of The Network Simulator (ns-2) simulations. © 2011 IEEE.Öğe Communications Technologies for Smart Grid Applications: A Review of Advances and Challenges(IGI Global, 2022) Tuna G.; Daş R.; Gungor V.C.Smart grid is a modern power grid infrastructure for improved efficiency, reliability, and safety, with smooth integration of renewable and alternative energy sources, through automated control and modern communications technologies. The smart grid offers several advantages over traditional power grids such as reduced operational costs and opening new markets to utility providers, direct communication with customer premises through advanced metering infrastructure, self-healing in case of power drops or outage, providing security against several types of attacks, and preserving power quality by increasing link quality. Typically, a heterogeneous set of networking technologies is found in the smart grid. In this chapter, smart grid communications technologies along with their advantages and disadvantages are explained. Moreover, research challenges and open research issues are provided. © 2022 by IGI Global. All rights reserved.Öğe Cyber wars and cyber threats against mobile devices: Analysis of mobile devices(IGI Global, 2023) Kayabaş H.; Tuna G.In recent years, the electronic device that has been used and bought the most by the consumers is mobile devices. Recently, there has been a significant increase in cyber crimes committed using mobile devices. It has been seen that this situation has become more critical with the widespread use of mobile devices in society, and it is of great importance to take some precautions. Unlike traditional crimes, detecting and analyzing these types of crimes requires special and technical knowledge. The detection of crimes committed using mobile devices is possible with the evidence obtained in accordance with the procedure. Therefore, in this study, a forensic analysis process in which data in a mobile device has been accessed and extracted using UFED 4PC mobile forensic software, and the acquired data has been analyzed using cellebrite physical analyzer has been carried out. As the analysis shows, these software-based tools can be used to extract mobile device data and analyze mobile devices with different brands, models, and operating systems. © 2023, IGI Global. All rights reserved.Öğe Design considerations for an environmental monitoring wireless acoustic sensor network(American Scientific Publishers, 2015) Potirakis S.M.; Nefzi B.; Tatlas N.-A.; Tuna G.; Rangoussi M.A wireless acoustic sensor network for the sound/acoustic monitoring of areas of environmental interest, and the automated generation of multi-level sound maps for environmental assessment has been recently proposed. This contribution focuses on the design considerations of such a network, and especially on the relation of specific performance factors, like the supported event sensing frequency, and density of the wireless nodes, with node operational parameters, like the required communication rate, data compression, local data storage and power autonomy. A simulation-based analysis provides useful information for the relation between competing design factors; this information can be employed for the selection of the hardware architecture on network and on node level, but also for the decision on the distribution of the processing effort between the local and the central processing units. Copyright © 2015 American Scientific Publishers All rights reserved.Öğe Design, development, and testing of web applications: Security aspects(IGI Global, 2023) Uçak U.; Tuna G.Today, with the changes and developments in software technologies, web applications have gained an important place by being actively used in many sectors. Due to the fact that web applications do not require installation costs and are easily accessible and operable, the increased usage rate in recent years makes these systems the target of cyber hackers. As a result of cyber attacks, services are blocked, and material and moral damages and data privacy violations are experienced. Within the scope of this study, web applications are explained, vulnerabilities that threaten software security and the measures that can be taken against these vulnerabilities are included. Particularly, security threats to web applications, security principles, secure software development lifecycles, test tools, and hardware and software products used for security are examined. In addition, SAMM and BSIMM models, which are maturity models used in secure software development, are discussed. © 2023, IGI Global.Öğe Effects of speed and measurement variance on the accuracy of mobile robot localisation(International Multidisciplinary Scientific Geoconference, 2018) Tuna G.; Savran D.Localisation and navigation are essential tasks for a mobile robot. If a mobile robot knows where it is, then it can make a plan to reach its destination. Localisation and navigation processes are not isolated from each other, they are closely linked. In fact, the ability for a mobile robot to localise itself is a basic requirement for reliable long-range autonomous navigation. Using sensory information about its environment, the mobile robot can perform actions dependent on this sensory information and navigate around. Although highly accurate localisation and mapping using low-cost hardware is very difficult, the emergence of new sensor technologies and development of state-of-the-art localisation and navigation algorithms help researchers and practitioners to realise their goals. In this study we evaluate the effects of speed and measurement variance on the accuracy of mobile robot localisation. As the results of our simulation studies prove, increasing speed and measurement variance of a mobile robot results in higher position error and velocity error. This indicates that high robot speed and high measurement variances may significantly reduce the accuracy of localisation algorithms. © SGEM 2018.Öğe Energy harvesting and battery technologies for powering wireless sensor networks(Elsevier Inc., 2016) Tuna G.; Gungor V.C.Due 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. © 2016 Elsevier Ltd. All rights reserved.Öğe Evaluations of different Simultaneous Localization and Mapping (SLAM) algorithms(2012) Tuna G.; Gulez K.; Cagri Gungor V.; Veli Mumcu T.Simultaneous Localization and Mapping (SLAM) algorithms with multiple autonomous robots have received considerable attention in recent years. In general, SLAM algorithms use odometry information and measurements from exteroceptive sensors of robots. The accuracy of these measurements and the performance of the corresponding SLAM algorithm directly affect the overall success of the system. This paper presents comparative performance evaluations of three Simultaneous Localization and Mapping (SLAM) algorithms using Extended Kalman Filter (EKF), Compressed Extended Kalman Filter (CEKF) and Unscented Kalman Filter (UKF). Specifically, it focuses on their SLAM performances and processing time requirements. To show the effect of CPU power on the processing time of SLAM algorithms, two notebooks and a netbook with different specifications have been used. Comparative simulation results show that processing time requirements are consistent with the computational complexities of SLAM algorithms. The results we obtained are consistent with the CPU power tests of independent organizations and show that higher processing power decreases processing time accordingly. The results also show that CEKF is more suitable for outdoor SLAM applications where there are a lot of natural and artificial features. © 2012 IEEE.Öğe GPS aided Extended Kalman Filter based localization for unmanned vehicles(2012) Tuna G.; Güngör V.C.; Gülez K.This paper presents design considerations of a GPS-aided localization system for unmanned vehicles used in outdoor applications. The system proposed in this paper is based on Extended Kalman Filter (EKF) and also integrates Global Positioning System (GPS) measurements. Localization and navigation systems are base components of all unmanned vehicles since they give unmanned vehicles the ability of perceiving the environment in order to localize themselves and to navigate to a target. The advantage of the proposed system over a GPS based localization system is that the system works even if the GPS receiver does not receive any GPS signals. In this study, firstly proposed EKF-based localization system is explained, and then how to integrate GPS measurements into this localization system is explained. With simulation studies in MATLAB, the effectiveness of the system is shown. The simulations show that the proposed localization system gives accurate results with negligible positional errors. © 2012 IEEE.Öğe Histogram based color object classification by multi-class support vector machine(2011) Mumcu T.V.; Aliskan I.; Gulez K.; Tuna G.This work presents a histogram based color object classification by SVM for laboratory automation. In the laboratory environment, existing problem is the classification of color objects which is understood as blob like pictures by the system via a camera. This automated system is located at hospitals, blood banks where we introduce the system different blood samples for different research purposes. The blood samples for different research purposes are realized with different colors of tube caps. These caps constitute the main problem here since their images are often blob like pictures. The segmented, multi color cap pictures are investigated in this paper by SVM for color object classification. To validate the performance of the system with SVM method, its output also compared to the other classification methods. In the future work different color spaces will be incorporated with SVM for better color classification. © 2011 Springer-Verlag.Öğe The impact of increasing number of nodes on the performance of well-known trust and reputation models for wireless sensor networks(Istanbul University, 2020) Tuna G.; Daş R.In recent years, several trust and reputation management models have been proposed to address the security issues of wireless sensor networks. In wireless sensor networks, trust and reputation management systems basically allow sensor nodes to make their own opinion about how trustworthy other nodes are so that a higher number of successful transactions can be obtained and the probability of being defrauded reduced. To assess the performance of trust and reputation management systems a number of performance metrics were proposed. In this study, with the aim of finding out the most suitable trust and reputation model when the number of sensor nodes involved in a wireless sensor network has been increased, the performance of EigenTrust, Linguistic Fuzzy Trust Mechanism, PeerTrust and PowerTrust is evaluated in terms of accuracy rate and path length. The reason for focusing on this is that if a trust and reputation model is able to achieve the same accuracy rate and path length performance without any performance degradation when more sensor nodes are involved in the network, it can be considered as scalable. The results of our simulation studies prove that compared to the other models, Linguistic Fuzzy Trust Mechanism provides higher accuracy and less path length scores and is more suitable for large-scale deployments of wireless sensor networks. © 2020 Istanbul University. All rights reserved.Öğe Integrated smart home services and smart wearable technology for the disabled and elderly(SciTePress, 2015) Tuna A.; Das R.; Tuna G.Smart Home is indeed a broad concept which includes the techniques and systems applied to living spaces. While its main goal is to reduce the consumption of energy, it provides many benefits including living in comfort, security and increasing flexibility. Smart homes are achieved through networking, control and automation technologies. Since smart homes offer more comfort and security and provide novel innovative services, people with disabilities or the elderly can take the advantages and improve their life quality. However, for such novel services, an analytical infrastructure which can manage overall data flow provided by various sensors, understand anomalous behaviour, and make necessary decisions. In this study, for efficient data handling and visualisation, an integrated smart service approach based on the use of a smart vest is proposed. The smart vest plays a key role in the proposed system since it provides the main health parameters of the monitored person to the smart home service and enables tracking of the monitored person's location. The proposed system offers many benefits to both people with disabilities and the elderly and their families in terms of increased efficiency of health care service and comfort for the monitored person. It can also reduce the cost of health care services by reducing the number of periodical visits.
