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Publication Metadata only An optimization framework for QoS-enabled adaptive video streaming over openflow networks(Institute of Electrical and Electronics Engineers (IEEE), 2013) Civanlar, Seyhan; N/A; Department of Electrical and Electronics Engineering; Eğilmez, Hilmi Enes; Tekalp, Ahmet Murat; Master Student; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; 26207OpenFlow is a programmable network protocol and associated hardware designed to effectively manage and direct traffic by decoupling control and forwarding layers of routing. This paper presents an analytical framework for optimization of forwarding decisions at the control layer to enable dynamic Quality of Service (QoS) over OpenFlow networks and discusses application of this framework to QoS-enabled streaming of scalable encoded videos with two QoS levels. We pose and solve optimization of dynamic QoS routing as a constrained shortest path problem, where we treat the base layer of scalable encoded video as a level-1 QoS flow, while the enhancement layers can be treated as level-2 QoS or best-effort flows. We provide experimental results which show that the proposed dynamic QoS framework achieves significant improvement in overall quality of streaming of scalable encoded videos under various coding configurations and network congestion scenarios.Publication Metadata only BitTorrent packet traffic features over IPv6 and IPv4(Elsevier, 2010) Ciflikli, Cebrail; Gezer, Ali; OzŞahin, A. Tuncay; Department of Computer Engineering; Özkasap, Öznur; Faculty Member; Department of Computer Engineering; College of Engineering; 113507At present, BitTorrent protocol packets constitute a large part of peer-to-peer application traffic on the Internet. Due to the increasing amount of BitTorrent traffic, it has become inevitable to take into account its effects on network management. Generally, studies on BitTorrent traffic measurement have involved analysis with packets transmitted via IPv4 protocol. However, with several facilities provided by IPv6 protocol, its traffic volume in operational networks is increasing day by day. New features of IPv6 enhance packet processing speeds over routers, switches and end systems. We consider that traffic features and packet traffic characteristics are likely to be affected with increasing amount of IPv6 protocol traffic. Therefore, it becomes significant to explore IPv6 packet traffic characteristics and application traffic features over IPv6. In this study, we investigate the IPv6 BitTorrent packet traffic characteristics in terms of autocorrelation, power spectral density and self similarity of packet size and packet interarrival time. We also perform distribution modeling for IPv4 and IPv6 BitTorrent packet traffic. With these models, efficient packet traffic traces are generated for network simulation studies. A detailed comparison is performed to determine differences between IPv4 and IPv6 BitTorrent packet traffic.Publication Metadata only Cross-layer framework for QoS support in wireless multimedia sensor networks(Institute of Electrical and Electronics Engineers (IEEE), 2012) Liang, Weifa; Department of Electrical and Electronics Engineering; N/A; Akan, Özgür Barış; Shah, Ghalib Asadullah; Faculty Member; N/A; Department of Electrical and Electronics Engineering; College of Engineering; N/A; 6647The emergence of wireless multimedia sensor networks (WMSNs) has made it possible to realize multimedia delivery on tiny sensing devices. The volume and characteristics of multimedia data is quite different from the data generated in WSNs that has raised the need to explore communication protocols for multimedia delivery in WMSNs. The existing studies focus on providing quality-of-service (QoS) to each individual source but they are not adaptive to create room for maximizing the number of sources. In this paper, we propose a novel cross-layer framework for QoS support in WMSNs. The objective of the proposed framework is to maximize the capacity of the deployed network to enhance the number of video sources given that the QoS constraint of each individual source is also preserved. This is achieved by implementing Wyner-Ziv lossy distributed source coding at the sensor node with variable group of pictures (GOP) size, exploiting multipath routing for real-time delivery and link adaptation to enhance the bandwidth under the given bit error rate. Hence, application requirements are mapped on joint operations of application, network, link and MAC layers to achieve the desired QoS. Simulation results reveal that the framework admits larger number of video sources under the satisfied distortion constraint.Publication Metadata only Delay-distortion optimization for content-adaptive video streaming(Institute of Electrical and Electronics Engineers (IEEE), 2007) N/A; N/A; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Özçelebi, Tanır; Tekalp, Ahmet Murat; Civanlar, Mehmet Reha; PhD Student; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; 26207; 16372We propose a new pre-roll delay-distortion optimization (DDO) framework that allows determination of the minimum pre-roll delay and distortion while ensuring continuous playback for on-demand content-adaptive video streaming over limited bitrate networks. The input video is first divided into temporal segments, which are assigned a relevance weight and a maximum distortion level, called relevance-distortion policy, which may be specified by the user. The system then encodes the input video according to the specified relevance-distortion policy, whereby the optimal spatial and temporal resolutions and quantization parameters, also called encoding parameters, are selected for each temporal segment. The optimal encoding parameters are computed using a novel, multi-objective optimization formulation, where a relevance weighted distortion measure and pre-roll delay are jointly minimized under maximum allowable buffer size, continuous playback, and maximum allowable distortion constraints. The performance of the system has been demonstrated for on-demand streaming of soccer videos with substantial improvement in the weighted distortion without any increase in pre-roll delay over a very low-bitrate network using AVC/H.264 encoding.Publication Metadata only Distributed qos architectures for multimedia streaming over software defined networks(Institute of Electrical and Electronics Engineers (IEEE), 2014) Eğilmez, Hilmi E.; Department of Electrical and Electronics Engineering; Tekalp, Ahmet Murat; Faculty Member; Department of Electrical and Electronics Engineering; College of Engineering; 26207This paper presents novel QoS extensions to distributed control plane architectures for multimedia delivery over large-scale, multi-operator Software Defined Networks (SDNs). We foresee that large-scale SDNs shall be managed by a distributed control plane consisting of multiple controllers, where each controller performs optimal QoS routing within its domain and shares summarized (aggregated) QoS routing information with other domain controllers to enable inter-domain QoS routing with reduced problem dimensionality. To this effect, this paper proposes (i) topology aggregation and link summarization methods to efficiently acquire network topology and state information, (ii) a general optimization framework for flow-based end-to-end QoS provision over multi-domain networks, and (iii) two distributed control plane designs by addressing the messaging between controllers for scalable and secure inter-domain QoS routing. We apply these extensions to streaming of layered videos and compare the performance of different control planes in terms of received video quality, communication cost and memory overhead. Our experimental results show that the proposed distributed solution closely approaches the global optimum (with full network state information) and nicely scales to large networks.Publication Metadata only Embedded web server-based home appliance networks(Academic Press Ltd Elsevier Science Ltd, 2007) N/A; Department of Computer Engineering; Department of Electrical and Electronics Engineering; Filibeli, Mustafa Can; Özkasap, Öznur; Civanlar, Mehmet Reha; Master Student; Faculty Member; Faculty Member; Department of Computer Engineering; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; 113507; 16372Powerful microcontrollers are used as parts ofmost home and office appliances of today. IntegratingwebserverstotheseintelligentdeviceswillaidincontrollingthemovertheInternetand alsoincreatingeffectiveuserinterfacesintheformofwebpages.Assigningmultiplefunctionalities toasinglebuttononanappliancehelpmanufacturerseconomizeuserinterfaces,but,thiscaneasily createconfusionfortheusers.Sincethecostofweb-basedinterfacesisconsiderablylow,theycanbe usedtoprovide the infrastructure for thedesignof simpleandmoreuser-friendly interfaces for householdappliances.Also,awebpagebasedinterfaceismucheasiertochange,whenneeded,as comparedtoahardware interface.Thispaperpresentsanovel approachtocontroldeviceswith embeddedwebserversovertheInternetandtoformdevicenetworkssuchthattheircomponentscan makeuseofoneanother’s servicesandfunctionswhile improving theuser interfaces.Themain benefitsofthisapproachincludeitslightweightdesign,automaticconfiguration,and,utilizationof widelyavailableandtestednetworkprotocolsofTCP/IPandHTTP.Thevalidityof theapproach hasbeenverifiedthroughaprototypesystemworkingwithrealappliances. r2006ElsevierLtd.All rightsreserved.Publication Open Access Highly efficient and re-executable private function evaluation with linear complexity(Institute of Electrical and Electronics Engineers (IEEE), 2022) Bingöl, Muhammed Ali; Kiraz, Mehmet Sabr; Levi, Albert; Department of Computer Engineering; Biçer, Osman; Department of Computer Engineering; Graduate School of Sciences and EngineeringPrivate function evaluation aims to securely compute a function f(x(1), ..., x(n)) without leaking any information other than what is revealed by the output, where f is a private input of one of the parties (say Party(1)) and x(i) is a private input of the ith party Party(i). In this article, we propose a novel and secure two-party private function evaluation (2PFE) scheme based on the DDH assumption. Our scheme introduces a reusability feature that significantly improves the state-of-the-art. Accordingly, our scheme has two variants, one is utilized in the initial execution of the function f, and the other is utilized in its subsequent evaluations. To the best of our knowledge, this is the first and most efficient 2PFE scheme that enjoys a reusablity feature. Our protocols achieve linear communication and computation complexities and a constant number of rounds which is at most three.Publication Metadata only Inner approximations of completely positive reformulations of mixed binary quadratic programs: a unified analysis(Taylor & Francis Ltd, 2017) Department of Industrial Engineering; Yıldırım, Emre Alper; Faculty Member; Department of Industrial Engineering; College of Engineering; 28415Every quadratic programming problem with a mix of continuous and binary variables can be equivalently reformulated as a completely positive optimization problem, that is, a linear optimization problem over the convex but computationally intractable cone of completely positive matrices. In this paper, we focus on general inner approximations of the cone of completely positive matrices on instances of completely positive optimization problems that arise from the reformulation of mixed binary quadratic programming problems. We provide a characterization of the feasibility of such an inner approximation as well as the optimal value of a feasible inner approximation. In particular, our results imply that polyhedral inner approximations are equivalent to a finite discretization of the feasible region of the original completely positive optimization problem. Our characterization yields, as a byproduct, an upper bound on the gap between the optimal value of an inner approximation and that of the original instance. We discuss the implications of this error bound for standard and box-constrained quadratic programs as well as general mixed binary quadratic programs with a bounded feasible region.Publication Metadata only Integrated semantic-syntactic video modeling for search and browsing(Institute of Electrical and Electronics Engineers (IEEE), 2004) Ekin, A; Mehrotra, R; Department of Electrical and Electronics Engineering; Tekalp, Ahmet Murat; Faculty Member; Department of Electrical and Electronics Engineering; College of Engineering; 26207Video processing and computer vision communities usually employ shot-based or object-based structural video models and associate low-level (color, texture, shape, and motion) and semantic descriptions (textual annotations) with these structural (syntactic) elements. Database and information retrieval communities, on the other hand, employ entity-relation or object-oriented models to model the semantics of multimedia documents. This paper proposes a new generic integrated semantic-syntactic video model to include all of these elements within a single framework to enable structured video search and browsing combining textual and low-level descriptors. The proposed model includes semantic entities (video objects and events) and the relations between them. We introduce a new "actor" entity to enable grouping of object roles in specific events. This context-dependent classification of attributes of an object allows for more efficient browsing and retrieval. The model also allows for decomposition of events into elementary motion units and elementary reaction/interaction units in order to access mid-level semantics and low-level video features. The instantiations of the model are expressed as graphs. Users can formulate flexible queries that can be translated into such graphs. Alternatively, users can input query graphs by editing an abstract model (model template). Search and retrieval is accomplished by matching the query graph with those instantiated models in the database. Examples and experimental results are provided to demonstrate the effectiveness of the proposed integrated modeling and querying framework.Publication Metadata only Learn2dance: learning statistical music-to-dance mappings for choreography synthesis(IEEE-Inst Electrical Electronics Engineers Inc, 2012) Department of Computer Engineering; Department of Computer Engineering; Department of Electrical and Electronics Engineering; N/A; Erzin, Engin; Yemez, Yücel; Tekalp, Ahmet Murat; Ofli, Ferda; Faculty Member; Faculty Member; Faculty Member; PhD Student; Department of Computer Engineering; Department of Electrical and Electronics Engineering; College of Engineering; College of Engineering; College of Engineering; Graduate School of Science and Engineering; 34503; 107907; 26207; N/AWe propose a novel framework for learning many-to-many statistical mappings from musical measures to dance figures towards generating plausible music-driven dance choreographies. We obtain music-to-dance mappings through use of four statistical models: 1) musical measure models, representing a many-to-one relation, each of which associates different melody patterns to a given dance figure via a hidden Markov model (HMM); 2) exchangeable figures model, which captures the diversity in a dance performance through a one-to-many relation, extracted by unsupervised clustering of musical measure segments based on melodic similarity; 3) figure transition model, which captures the intrinsic dependencies of dance figure sequences via an n-gram model; 4) dance figure models, capturing the variations in the way particular dance figures are performed, by modeling the motion trajectory of each dance figure via an HMM. Based on the first three of these statistical mappings, we define a discrete HMM and synthesize alternative dance figure sequences by employing a modified Viterbi algorithm. The motion parameters of the dance figures in the synthesized choreography are then computed using the dance figure models. Finally, the generated motion parameters are animated synchronously with the musical audio using a 3-D character model. Objective and subjective evaluation results demonstrate that the proposed framework is able to produce compelling music-driven choreographies.