Computer Engineering / Bilgisayar Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/10
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Conference Object Deep Convolutional Neural Networks for Viability Analysis Directly From Cell Holograms Captured Using Lensless Holographic Microscopy(The Chemical and Biological Microsystems Society (CBMS), 2019) Delikoyun, Kerem; Çine, Ersin; Anıl İnevi, Müge; Özçivici, Engin; Özuysal, Mustafa; Tekin, Hüseyin CumhurCell viability analysis is one of the most widely used protocols in the fields of biomedical sciences. Traditional methods are prone to human error and require high-cost and bulky instrumentations. Lensless digital inline holographic microscopy (LDIHM) offers low-cost and high resolution imaging. However, recorded holograms should be digitally reconstructed to obtain real images, which requires intense computational work. We introduce a deep transfer learning-based cell viability classification method that directly processes the hologram without reconstruction. This new model is only trained once and viability of each cell can be predicted from its hologram. © 2019 CBMS-0001.Conference Object Citation - Scopus: 1Distributed Identity Based Private Key Generation for Scada Systems(Springer, 2013) Kılınç, Görkem; Nai Fovino, IgorThe security of the ICT (Information Communications Technology) components of industrial systems is gaining great importance in the context of their criticality for society at large. There is an urgent need for the consideration of security in their design, and for the analysis of the related vulnerabilities and potential threats. The high exposure of industrial critical infrastructure to such threats is mainly due to the intrinsic weakness of the communication protocols used to control the process network. The peculiarities of the industrial protocols (low computational power, large geographical distribution, near to real-time constraints) make hard the effective use of traditional cryptographic schemes and in particular the implementation of a effective key management infrastructure supporting a cryptographic layer. In this paper we present the first working prototype of a distributed key generation infrastructure for SCADA systems based on the well known identity based crypto-paradigm. © 2013 Springer-Verlag.Conference Object Citation - Scopus: 4Test Case Generation for Firewall Implementation Testing Using Software Testing Techniques(Tafford Publishing, 2008) Tuğlular, TuğkanThe firewall implementation testing approach checks actions performed by the firewall with respect to corresponding firewall rules. This type of firewall testing can be implemented by developing test cases from firewall rule sequence, generating test packets using those test cases and injecting those test packets into the firewall. Although this method has been already defined in the academic world, an approach to generate test cases does not exist in the literature. In this work, a test case generation approach is developed using software testing techniques. © 2008 Atilla Elçi.Conference Object The Performance Results of Ecdsa Implementation on Different Coordinate Systems(Tafford Publishing, 2008) Atay, SerapElliptic Curve Cryptography has a high computational cost due to arithmetic operations of point addition and point doubling. But the cost can be reduced if different coordinate systems utilized. This paper shows that the performance of an elliptic curve digital signature algorithm (ECDSA) can be significantly increased by using different coordinate systems.Conference Object On Ntru and Its Performance(Tafford Publishing, 2008) Mersin, Ali; Beyazıt, MutluHardness of lattice problems has introduced a new candidate for public key cryptosystems. NTRU is one of such cryptosystems. The fact that it works with small integers and that the complexities of key generation, encryption and decryption are relatively small leads to good overall performance when compared to the other public key cryptosystems. The aim of this study is to make a theoretical to practical introduction to NTRU and investigate how it performs against popular public key cryptosystems such as RSA and, especially, ECC. © 2008 Atilla Elçi.Conference Object A Memory Management Model for Cryptographic Software Libraries(Tafford Publishing, 2008) Mersin, Ali; Beyazıt, MutluCryptographic protocols are implemented on the abstraction of multiple precision number libraries in which the dominant design criterion mostly turns out to be the maximization of the system performance. In contrast, each protocol may have its own memory usage pattern. In general case, the memory allocation and release routines are frequently called during the runtime. For this reason, an improper memory management strategy may yield an inefficient implementation. In this paper, we propose a memory management technique which is constructed under the consideration of the context of high level cryptographic software running on multi-programmed environments. Also, we show the implementation results of our approach and discuss with respect to the common static and dynamic memory allocation strategies. © 2008 Atilla Elçi.Conference Object Monitoring of Policy Operations in a Distributed Firewall Environment(2008) Çakı, Oğuzhan; Tuğlular, Tuğkan; Çetin, FüsunDistributed firewalls concept has been introduced to overcome some drawbacks of traditional firewalls. Distributed firewall approach is based on the idea of enforcing policy rules at the intermediate and end points rather than a single entry point to the network. Management of policy rules in a distributed firewall environment requires surveillance of policy operations performed on each firewall. With this paper, we propose a monitoring architecture and its application prototype for distributed firewalls to keep track of actions, such as create, read, update, and delete, carried out on policy rule sets. We performed some emulation and laboratory experiments to obtain operational values of the proposed architecture. ©2008 by Bo?aziçi University.Book Part Citation - Scopus: 2A Survey on Security in Wireless Sensor Networks: Attacks and Defense Mechanisms(IGI Global, 2013) Tekbacak, Fatih; Dalkılıç, Mehmet Emin; Korkmaz, İlker; Dağdeviren, OrhanWireless Sensor Network (WSN) is a promising technology that has attracted the interest of research in the last decade. Security is one of the fundamental issues in sensor networks since sensor nodes are very resource constrained. An attacker may modify, insert, and delete new hardware and software components to the system where a single node, a specific part of the sensing area, and the whole network may become inoperable. Thus, the design of early attack detection and defense mechanisms must be carefully considered. In this chapter, the authors survey attacks and their defense mechanisms in WSNs. Attacks are categorized according to the related protocol layer. They also investigate the open research issues and emerging technologies on security in WSNs.Article Citation - WoS: 4Citation - Scopus: 5Query optimization: Mobile agents versus accuracy of the cost estimation(CRL Publishing, 2005) Özakar, Belgin; Morvan, F.; Hameurlaint, A.Since an increasing number of diverse sources of data and information become available through World Wide Web, the field of distributed heterogeneous query processing attracts attention of the researchers. One of the main concerns is to reduce the amount of communication and the volume of data transferred in terms of query optimization where it is a real challenge to have the statistics of the resources predictable and up-to-date. Autonomy, proactivity and mobility features of mobile agents seem promising under some conditions. In this paper we are interested in the study of the efficiency of the mobile agents in relation with the approach of the cost model used during the optimization process. We present an execution model based on mobile agents. Performance evaluation shows the efficiency intervals of the execution model according to the estimation errors and the current state of the system. The major contribution of this paper is to point out the effective use of an execution model based on mobile agents in relation with the approach of the cost model and with the query type. © 2005 CRL Publishing Ltd.Article Citation - WoS: 3Citation - Scopus: 4Affordable person detection in omnidirectional cameras using radial integral channel features(Springer Verlag, 2019) Demiröz, Barış Evrim; Salah, Albert Ali; Baştanlar, Yalın; Akarun, LaleOmnidirectional cameras cover more ground than perspective cameras, at the expense of resolution. Their comprehensive field of view makes omnidirectional cameras appealing for security and ambient intelligence applications. Person detection is usually a core part of such applications. Conventional methods fail for omnidirectional images due to different image geometry and formation. In this study, we propose a method for person detection in omnidirectional images, which is based on the integral channel features approach. Features are extracted from various channels, such as LUV and gradient magnitude, and classified using boosted decision trees. Features are pixel sums inside annular sectors (doughnut slice shapes) contained by the detection window. We also propose a novel data structure called radial integral image that allows to calculate sums inside annular sectors efficiently. We have shown with experiments that our method outperforms the previous state of the art and uses significantly less computational resources.