Now showing items 1-20 of 30

  • A Novel Image Steganography Technique based on Similarity of Bits Pairs 

    Authors:Shehzad, Danish; Daǧ, Tamer
    Publisher and Date:(IEEE, 2017)
    Steganography is one of the most important information hiding mechanism which can be used along with cryptography for providing adequate data security. The common Steganographic mediums used are text image audio and video for hiding secret information. In the case of image medium mostly least significant bits of pixels of a cover image are used for hiding secret information. In this paper a new technique based on pairs matching is proposed data bits of the message to be secured are arranged in ...

  • A review on the recent energy-efficient approaches for the Internet protocol stack 

    Authors:Cengiz, Korhan; Daǧ, Tamer
    Publisher and Date:(Springeropen, 2015)
    The reduction of energy consumption has become a key research area for the information and communication technology (ICT) industry due to economical environmental and marketing reasons. While the environmental direction aims at minimization of greenhouse gas emissions by enforcing the usage of renewable energy in the ICT industry economical and marketing directions lead researchers to design low-power components or develop and enhance energy-saving protocols without an impact on the level of the ...

  • An energy efficient routing algorithm (X-Centric routing) for sensor networks 

    Authors:Atac, Goktug; Daǧ, Tamer
    Publisher and Date:(INT INST Informatics & Systemics, 2011)
    Recent developments in wireless communications and electronics technologies have enabled the progress in low cost sensor networks. Sensor networks differ from traditional networks in several ways such as the severe energy constraints redundant low-rate date and many-to-one flows that the sensor networks require. One of the major challenges facing the design of a routing protocol for Wireless Sensor Networks (WSNs) is to find the most reliable path between the sources and the sink node by considering ...

  • Automatic detection of mgd level (Meibomian gland dysfunction) 

    Authors:Bütün, Alp Eren
    Publisher and Date:(Kadir Has University, 2019)
    MGD is a common, clinical disease which is the major cause of dry eye. Meibography is a study in order to observe meibomian glands. A meibography image is the infrared photograph of the inner part of eyelids of the patient. Physicians are using meibography images to diagnose MGD. The important result from the infrared meibography image is the level of the disease. Using the level, the appropriate treatment is decided by the physician. Aim of this thesis is to develop the automatic software to ...

  • Developing novel techniques for spatial domain LSB i̇mage steganography 

    Authors:Shehzad, Danish
    Publisher and Date:(Kadir Has University, 2019)
    Steganography is one of the most noteworthy information hiding mechanism, which is used as an alternative to cryptography in order to provide adequate data security. Image steganography is one of the key types of steganography where a message to be transmitted is hidden inside a cover image. The most commonly used techniques for image steganography rely on LSB Steganography. In this thesis, new techniques are developed for LSB image steganography to achieve maximum security, optimal data capacity ...

  • Dynamic Multi Threshold Priority Packet Scheduling Algorithms 

    Authors:Daǧ, Tamer; Uzungenc, Sezer
    Publisher and Date:(EDP Sciences, 2015)
    Packet scheduling algorithms are developed in order to use shared transmission resources efficiently. Various application packets such as real and non-real time packets might have different QoS requirements and traditional scheduling algorithms might be insufficient to respond to the applications needs. In this paper two packet scheduling algorithms are proposed to overcome this problem: Dynamic multi threshold priority packet scheduling (DMTPS) and dynamic multi threshold priority with urgency ...

  • Dynamic Priority Packet Scheduler with Deadline Considerations (DPD) 

    Authors:Daǧ, Tamer
    Publisher and Date:(INT INST Informatics & Systemics, 2010)
    Providing quality of service (QoS) to applications with different traffic characteristics based on their needs is an important research area for today's and tomorrow's high speed networks. Various techniques have been proposed to achieve good QoS for diverse application types. Among these techniques packet scheduling algorithms decide on how to process packets at network nodes

  • Energy Aware Multi-Hop Routing Protocol for WSNs 

    Authors:Cengiz, Korhan; Daǧ, Tamer
    Publisher and Date:(IEEE, 2018)
    In this paper we propose an energy-efficient multi-hop routing protocol for wireless sensor networks (WSNs). The nature of sensor nodes with limited batteries and inefficient protocols are the key limiting factors of the sensor network lifetime. We aim to provide for a green routing protocol that can be implemented in a wireless sensor network. Our proposed protocol's most significant achievement is the reduction of the excessive overhead typically seen in most of the routing protocols by employing ...

  • Extending the lifetime of WSNs with Maximum Energy Selection Algorithm (MESA) 

    The limited battery supply of a sensor node is one of the most important factors that limit the lifetime of the WSNs. As a consequence increasing the lifetime of WSNs through energy efficient mechanisms has become a challenging research area. Previous studies have shown that instead of implementing direct transmission or multi-hop routing clustering can significantly improve the total energy dissipation and lifetime of a WSN. The traditional LEACH and LEACH based algorithms have evolved from this ...

  • Extending the Lifetime of WSNs with Maximum Energy Selection Algorithm (MESA) 

    Authors:Cengiz, Korhan; Daǧ, Tamer
    Publisher and Date:(IEEE, 2016)
    The limited battery supply of a sensor node is one of the most important factors that limit the lifetime of the WSNs. As a consequence increasing the lifetime of WSNs through energy efficient mechanisms has become a challenging research area. Previous studies have shown that instead of implementing direct transmission or multi-hop routing clustering can significantly improve the total energy dissipation and lifetime of a WSN. The traditional LEACH and LEACH based algorithms have evolved from this ...

  • Implementation of a SDN (Software defined network) 

    Improving resource efficiency enhancing network security and achieving simpler network management have become the main goals for networking in the previous years. To accomplish these ideas an efficient routing traffic monitoring access control and server load balancing systems need to be designed. However these objectives make the optimization and management of networks rather difficult. In this paper Software Defined Networks (SDN) an alternative way for creating an optimized network by taking ...

  • Importance of Regional Differences in Brain Throughout Aging for Down Syndrome 

    Down syndrome (DS) which affects approximately one in 700 live births is caused by an extra copy of the long arm of human chromosome 21 (HSA21). Statistical analysis has been done for understanding the protein expression profiles based on age and sex differences in DS. In addition there are ongoing research efforts for comprehending expression patterns based on different brain regions. However little is known about the mechanisms of expression differences in brain regions throughout aging. Insights ...

  • Improving Energy-Efficiency of WSNs through LEFCA 

    Authors:Cengiz, Korhan; Daǧ, Tamer
    Publisher and Date:(Sage Publications Inc, 2016)
    Wireless sensor networks (WSNs) have become an important part of our lives as they can be used in vast application areas from disaster relief to health care. As a consequence the life span and the energy consumption of a WSN have become a challenging research area. According to the existing studies instead of using direct transmission or multihop routing clustering can significantly reduce the energy consumption of sensor nodes and can prolong the lifetime of a WSN. In this paper we propose a low ...

  • In silico identification of critical proteins associated with learning process and immune system for Down syndrome 

    Authors:Kulan, Handan; Daǧ, Tamer
    Publisher and Date:(Public Library Science, 2019)
    Understanding expression levels of proteins and their interactions is a key factor to diagnose and explain the Down syndrome which can be considered as the most prevalent reason of intellectual disability in human beings. In the previous studies the expression levels of 77 proteins obtained from normal genotype control mice and from trisomic Ts65Dn mice have been analyzed after training in contextual fear conditioning with and without injection of the memantine drug using statistical methods and ...

  • Low Energy Fixed Clustering Algorithm (LEFCA) for Wireless Sensor Networks 

    Authors:Cengiz, Korhan; Daǧ, Tamer
    Publisher and Date:(IEEE, 2015)
    Wireless sensor networks (WSNs) have become an important part of our lives as they can be used in vast application areas from disaster relief to health care. As a consequence the life span and the energy consumption of a WSN has become a challenging research area. According to the existing studies instead of using direct transmission or multi-hop routing clustering can significantly reduce the energy consumption of sensor nodes and can prolong the lifetime of a WSN. In this paper we propose a low ...

  • Low energy fixed clustering algorithm for wireless sensor networks 

    Authors:Cengiz, Korhan
    Publisher and Date:(Kadir Has University, 2016)
    Wireless sensor networks (WSNs) have become an important part of our lives as they can be used in vast application areas from disaster relief to health care. As a consequence the life span and the energy consumption of a WSN has become a challenging research area. According to the existing studies instead of using direct transmission or multi-hop routing clustering can significantly reduce the energy consumption of sensor nodes and can prolong the lifetime of a WSN. in this thesis low energy fixed ...

  • Max-pivot routing for opportunistic networks 

    Authors:Daǧ, Tamer
    Publisher and Date:(2013)
    Opportunistic networks are challenging types of networks where network connections are imminent. Network topologies are dynamic and can rapidly change. A path between a source node and a destination node may or may not exist the network can be disconnected. This type of behavior observed under opportunistic networks makes classical networking solutions impractical. Thus traditional routing algorithms are not suitable for such networks and will not be useful. Although flooding might be seen as the ...

  • Multi-hop low energy fixed clustering algorithm (M-LEFCA) for WSNs 

    The limited battery supply of sensor nodes is one of the most important factors which restrict the lifetime of the wireless sensor networks (WSNs). As a consequence the wide deployment of WSNs in the recent years led to the necessity of extending the lifetime through energy efficient mechanisms. Previous studies have shown that instead of implementing direct transmission in a WSN field to collect data clustering can significantly improve the energy-efficiency and thus the lifetime. The traditional ...

  • Multi-Hop Low Energy Fixed Clustering Algorithm (M-LEFCA) for WSNs 

    Authors:Cengiz, Korhan; Daǧ, Tamer
    Publisher and Date:(IEEE, 2016)
    The limited battery supply of sensor nodes is one of the most important factors which restrict the lifetime of the wireless sensor networks (WSNs). As a consequence the wide deployment of WSNs in the recent years led to the necessity of extending the lifetime through energy efficient mechanisms. Previous studies have shown that instead of implementing direct transmission in a WSN field to collect data clustering can significantly improve the energy-efficiency and thus the lifetime. The traditional ...

  • Nearest Fixed Clustering Algorithm (NFCA) for Wireless Sensor Networks 

    The objective of reducing energy consumption at the sensor nodes has become a key research area for wireless sensor networks (WSNs) in recent years. With the steady increase in the cost of energy the existing algorithms and protocols need to be redeveloped. In this paper an energy-efficient routing protocol which forms fixed clusters is proposed. The new cluster head (CH) selections are made based on selecting nearest nodes to the current CH. The proposed protocol includes two phases to achieve ...