My publications
Network Load Effects on Wireless Sensor Network Node Activity
by Zuhal Can and Elif Değirmenci, Eskişehir Türk Dünyası Uygulama ve Araştırma Merkezi Bilişim Dergisi, 2022
Abstract:
Due to the failure-prone and vulnerable structure of WSN nodes, understanding the typical activity patterns of nodes helps identify the faulty and malicious node activities and differentiate normal node behaviors from abnormal node behaviors. In this study, for understanding the typical node activities, we observe the effects of the network load on energy consumption, packet throughput, and latency parameters. We run simulations of networks with a variable number of sinks up to 5 in a network of various sizes. We observed a growth in the network load as the source and sink node request activities increased. We found that increasing the number of sinks affects the overall network load and causes communication delays between the source and sink node.
Kurum İçi Maske Tespit ve Uyarı Sistemi
by Zuhal Can
Abstract:
Pandemi sürecinde maske kullanmak, koronanın, damlacık yoluyla bulaşmasının önüne geçen bir çözüm olmasına karşın, takılı olduğunda nefes almayı zorlaştırması ve bunaltıcı bir etki yaratması sebebiyle, insanların zaman zaman ihmal ettiği bir uygulamadır. Kurumlarda, insanların maskelerini doğru takıp takmadığını denetleyebilmek, pandeminin gidişatını ve virüsün yayılımını kontrol altına almak ve en aza indirmek adına çok önemlidir. Bu çalışmada geliştirilen kurum içi maske tespit ve uyarı sistemi, kamera görüntülerinin gerçek zamanlı analiz edilmesiyle, bireylerin kurum içinde maskelerinin takılı olup olmadığını denetler. Bu sistemde, derin öğrenme metodları kullanılarak, analiz edilen görüntüde yer alan yüzler tespit edilir, maskeli olup olmadıkları saptanır ve bir e-posta uyarı sistemi ile maskesiz çalışanlar uyarılır.
Effects of Network Density in Detecting Node Abnormality in Wireless Sensor Networks
by Zuhal Can and Elif Değirmenci, ICITBDIT, 2020
Abstract:
With the novel developments in Wireless Sensor Network (WSN) technologies, understanding node patterns have become critical for enabling security since the vulnerable structure of WSN nodes is a drawback of the technological developments in the area. Understanding node activity patterns helps to detect abnormal node behaviors and prevent malicious nodes. In this study, we observe diverse node activity patterns in terms of packet reception, packet transmission, and energy utilization. We also observe the network delay pattern between the source and sink according to various network sizes.
Querying on Federated Sensor Networks
by Zuhal Can and Murat Demirbas, Journal of Sensor and Actuator Networks, 2016
Abstract:
A Federated Sensor Network (FSN) is a network of geographically distributed Wireless Sensor Networks (WSNs) called islands. For querying on an FSN, we introduce the Layered Federated Sensor Network (L-FSN) Protocol. For layered management, L-FSN provides communication among islands by its inter-island querying protocol by which a query packet routing path is determined according to some path selection policies. L-FSN allows autonomous management of each island by island-specific intra-island querying protocols that can be selected according to island properties. We evaluate the applicability of L-FSN and compare the L-FSN protocol with various querying protocols running on the flat federation model. Flat federation is a method to federate islands by running a single querying protocol on an entire FSN without distinguishing communication among and within islands. For flat federation, we select a querying protocol from geometrical, hierarchical cluster-based, hash-based, and tree-based WSN querying protocol categories. We found that a layered federation of islands by L-FSN increases the querying performance with respect to energy-efficiency, query resolving distance, and query resolving latency. Moreover, L-FSN’s flexibility of choosing intra-island querying protocols regarding the island size brings advantages on energy-efficiency and query resolving latency.
Smartphone-based data collection from wireless sensor networks in an urban environment
by Zuhal Can and Murat Demirbas, Journal of Network and Computer Applications, 2015
Abstract:
Using smartphones as mobile basestations and leveraging human mobility is a promising approach for urban data collection from Wireless Sensor Networks (WSNs). In this paper, we evaluate the feasibility of this approach applying analyses on a city-wide mobility dataset. Our spatial analysis shows that popular locations cluster close to each other and sensor nodes located in rarely visited locations can transmit their data in a few hops to smartphones visiting these popular locations. Our energy-efficiency analysis indicates the feasibility of employing energy-conserving approaches on both smartphones and WSN nodes based on mobility behavior of smartphone users. We evaluated and compared on-demand and continuous data collection protocols on several WSN islands with different size and connectivity regarding to data collection efficiency. Our simulation results show that continuous data collection protocols surpass on-demand data collection protocols in terms of data delivery ratio and latency. We found that data collection protocols run more efficiently in many-connected small islands compared to fewer connected large islands.
Energy-efficient Smartphone-based Data Collection from Wireless Sensor Networks
by Zuhal Can and Murat Demirbas, IEEE CCNC, 2015
Abstract:
We develop the Periodic Listening Medium Access Control protocol (PLMAC) to improve energy-efficiency for smartphone-based data collection applications. PLMAC decreases the idle listening period of network nodes with a duty cycling schedule based on neighbor node visits. In a smartphone-based data collection application, network nodes run mostly in the idle listening operation for detecting a smartphone visit. The duty cycling mechanism of PLMAC allows nodes to sleep most of the time with a sleep/listen schedule. When a node is visited by a smartphone user, its neighbor nodes adjust their listening period to be long enough to communicate with an approaching smartphone. By analyzing a mobility dataset, we validate the need for a duty cycling schedule based on neighbor node visits. PLMAC runs in collaboration with the B-MAC protocol. We found that PLMAC's duty cycling mechanism results in better energy-efficiency than B-MAC.
A survey on in-network querying and tracking services for wireless sensor networks
by Zuhal Can and Murat Demirbas, Ad Hoc Networks, 2013
Abstract:
In wireless sensor networks, querying services purpose to detect static events while tracking services continuously monitor mobile events. This paper surveys and discusses in-network querying and tracking services for static and mobile networks. Querying and tracking services are categorized by tree-based, hierarchical cluster-based, geometrical and hash-based. Mobility effects of network units and several design metrics including energy-efficiency, distance-sensitivity, scalability and fault-tolerance are also discussed. The paper includes open research issues for querying and tracking services in various domains.
Investigation of querying techniques for federated sensor networks
by Murat Demirbas and Zuhal Can, IWCMC, 2011
Abstract:
Federated sensor networks (FSNs) connect and combine several partitioned wireless sensor networks (WSNs) to extend the scope of WSNs to larger scale geographical areas. The federated and sparsely/intermittently connected nature of FSNs introduce several challenges for deploying middleware services such as routing, querying, tracking, time synchronization. In this paper, we investigate the challenges for deploying a querying service on FSNs. We review several querying protocols proposed in the WSNs literature and identify the applicability and shortcomings of these protocols for FSNs. Based on our investigation, we suggest open research directions for building an efficient querying service for FSNs.
My PhD dissertation
IN-NETWORK QUERYING ON FEDERATED SENSOR NETWORKS
by Zuhal Can, 2015, (Order No. 3714548). Available from Proquest Dissertations & Theses @ SUNY Buffalo. (1709470282).
Abstract:
Querying and tracking are two major in-network data processing services for Wireless Sensor Networks (WSNs). Although there are several in-network querying and tracking protocols in the WSNs literature, those protocols are not directly applicable for large-scale federated/partitioned WSN deployments where loss of connectivity and network partitioning is a norm rather than an exception. Due to large-scale federated/partitioned deployment characteristics, a so-called Federated Sensor Network (FSN) needs to cope with the distribution and sparse-connectivity of distinct WSN islands via interspace network of either mobile or static relay nodes.
This dissertation investigates the characteristics of FSNs for designing resilient querying and tracking services. The federated and sparsely/intermittently connected nature of FSNs introduces several challenges for deploying middleware services such as routing, querying, and tracking. In this dissertation, effective information querying from FSN islands using in-network data processing and indexing techniques is explained by static and mobile federation of FSN islands.
For static federation, the challenges for deploying a querying service on both flat and layered FSN models are investigated. Several querying protocols proposed in the WSNs literature are applied and reviewed, and the shortcomings of these protocols are identified for the flat FSN management by several simulation results. The layered federation of islands by the L-FSN protocol is found to be alleviating the shortcomings of flat federation and increasing the querying performance compared to flat federation. L-FSN allows islands to be managed autonomously by a degree of privacy. Inter-island querying of L-FSN is based on the path selection policies while intra-island querying protocols of L-FSN can be selected according to the size of islands to gain benefit on energy-efficiency and query resolving latency. In order to suggest directions for future intra-island querying protocols, this dissertation presents a review of in-network querying and tracking protocols in static and mobile WSNs under the categorizations of geometrical, hierarchical cluster-based, hash-based, and tree-based.
For mobile federation, a mobility dataset is analyzed to understand and highlight the characteristics of the federation of FSN islands by smartphones as mobile relay nodes. The analysis of this mobility dataset revealed the existence of island regions in an urban area which lack regular visitors. Since these islands are found to be adjacent to city roads, multi-hop data collection is feasible from island nodes by smartphone users traveling on city roads. This analysis discusses the spatial and energy-related opportunities of mobile federation by smartphones. In the light of this analysis, the duty cycling PLMAC protocol is proposed to conserve energy on islands for smartphone-based data collection applications.