Turgay Korkmaz

• PhD
• Professor (Associate) at The University of Texas at San Antonio

Edge computing is emerging as a key enabler of low-latency, high-efficiency processing for the Internet of Things (IoT) and other real-time applications. To support these demands, containerization has gained traction in edge computing due to its lightweight virtualization and efficient resource management. However, there is currently no established...

The rapid expansion of IoT devices and their real-time applications have driven a growing need for edge computing. To meet this need, efficient and secure solutions are required for running such applications on resource-constrained devices with limited power, CPU, and memory. Unikernel, with its minimalistic design and application-specific approach...

In the evolving tech landscape, various container technologies coexist and offer compelling advantages in quickly deploying applications and efficiently utilizing resources on edge devices. Despite the potential benefits of containerization in general, limited research has explored how various container technologies perform in specific domains. In...

The proliferation of IoT devices has led to various computer vision applications, where addressing bandwidth and latency challenges through edge nodes presents significant benefits. However, there are still existing gaps and a need for improvements to optimize IoT applications, especially in the field of computer vision, by overcoming limited resou...

Internet-of-Things (IoT) devices continuously gather data and send the data to the cloud for further processing. However, with the recent trend of increasing number of IoT devices, billions of devices are anticipated to send data to the cloud, eventually impacting performance and cost. To solve this problem, one way is to process data locally insid...

Software Defined Networking (SDN) has emerged as a promising paradigm with the key idea of separating control and data planes. However, this separation causes various scalability issues (e.g., increased response time, overhead on the controller and core SDN switches) in Wide Area Networks (WANs). While addressing such scalability issues, it is impo...

In this paper, we compared the existing routing algorithms in the context of Software Defined Networking ( SDN ), where a logically centralized controller acquires the global view of the network, selects the paths using a routing algorithm, and installs the determined routing rules to the switches. We divided existing routing algorithms (RA) into...

Software Defined Networking (SDN) has emerged as a promising paradigm to make network management easier while supporting various applications requiring different guarantees in terms of performance, availability and correctness. In essence, SDN decouples the control and data planes such that a logically centralized SDN controller finds the paths bas...

When a link fails in Software Defined Networks (SDN), the flows that use the failed link need to be rerouted over other paths. To achieve this rerouting task, researchers have proposed reactive and proactive recovery approaches. In reactive approach, upon failure, SDN controller computes new paths for the affected flows and installs them on demand....

This paper presents the design and evaluation of a novel project designed to facilitate the learning of memory management concepts and interactions between different components. This project removes the complexity of a full or specific operating system by implementing memory management inside the user space. Evaluation results show that the mean ex...

Mobility within Wireless Sensor Networks (WSNs) has been widely considered for data collection tasks, where mobile robots physically collect the data from the sensors and return to the base station. Although this approach has proven to be useful in prolonging the lifetime of these networks, it cannot meet the requirements of real-time data collecti...

Routing a given set of flows with bandwidth requirements is a fundamental problem, which has been formulated as Unsplittable Flow Problem (UFP). One of the key issues in this formulation is that the bandwidth requirement is fixed for each flow. In practice, however, many applications (e.g., video-on-demand, backup and replication services) would gr...

Large scale cloud applications may require users to get multiple resources (e.g., VMs, storage) from different sites and simultaneously connect each pair of resources by a path that can satisfy certain Quality-of-Service (QoS) requirements. Finding such paths with the bandwidth constraint is known as the unsplittiable flow problem, which is shown t...

Numerous algorithms have been proposed for the well-known multi-constrained shortest path (MCSP) problem, but very few have good practical performance in case of two or more constraints. In this paper, we propose a new Lagrangian relaxation algorithm to solve a generalized version of the MCSP problem where we search for multiple shortest paths subj...

Mobile robots have been used to collect data in the network in order to reduce the energy consumed when forwarding data. In order to be energy efficient, mobile robots should be deployed and controlled in such a way as to minimize travel distance. To do this, we examined multiple deployment and movement policies and their effects on the performance...

Wireless multimedia sensor networks can provide a much clearer picture of the sensed area and thus significantly improve many applications. However, the increased amount of data will lead to issues with energy consumption and network lifetimes if we use the traditional network-based data collection where packets are forwarded hop by hop to the base...

Annotating and understanding the function of proteins and other elements in a genome can be difficult in the absence of a well-studied and evolutionarily close relative. The causative agent of malaria, one of the oldest and most deadly global infectious diseases, is a good example of this problem. The burden of malaria is huge and there is a pressi...

Graph indexing and querying mechanisms have been receiving significant attention due to their importance in analyzing the growing graph datasets in many domains. Although much work has been done in the context of simple graphs, they are not directly applicable to hypergraphs that represent more complex relationships in various applications. The key...

Mining web log datasets has been extensively studied using Frequent Pattern Mining (FPM) and its various other forms. Identifyingfrequent patterns in different sequences can help in analyzing the most common sub-sequences (e.g., the pages visitedtogether). However, this approach would not be able to identify general structures spanning over multipl...

It is important to mine the weblog dataset to find interesting and helpful information. There are three kinds of mining on weblog data which are web usage mining, web structure mining and web content mining. In our research, we are going to investigate web pages structure and find the most evident groups of users and web pages. Nowadays, big data i...

Mobility within Wireless Sensor Networks (WSNs) has proven to be quite useful in prolonging the lifetime of these networks. This mobility requires intelligent control of the robots in order to efficiently complete tasks within the network. If the tasks required of the network need to send audio-video data back to the base station, then we need to m...

Malaria is one of the most deadly infectious diseases in the world. The malaria burden is characterized by 207 million cases and over 627,000 deaths annually. The consistent morbidity and mortality underscore an urgent need for the development of next-generation antimalarials. In this paper, we propose a network mining approach to uncover the prote...

Due to the importance of Frequent Pattern Mining (FPM) in bioinformatics, web mining, social networks and so on, researchers have been paying significant attention to FPM and its various forms. In this study, we introduce a new form that we call super-sequence pattern mining. In contrast to frequent sub-sequence pattern mining studied significantly...

Considerable efforts have been dedicated to develop both heuristic and approximation algorithms for the NP-complete delay-constrained least-cost (DCLC) routing problem, but to the best of our knowledge, no prior work has been done to mingle the two tracks of research. In this letter we introduce a novel idea to show how a heuristic method can be us...

Understanding the topological characteristics of communications networks is essential to the design and operation of such networks. Accordingly, the researchers have been analyzing the topological characteristics of various networks. In this paper, we focus on multi-hop wireless networks with uniformly distributed nodes in 2D and 3D environments. U...

Wireless Multimedia Sensor Networks are a budding topic for researchers which could vastly improve many applications, such as border monitoring networks. The increased amount of data leads to greater issues with energy consumption and decreased network lifetimes. To mitigate these problems, the use of mobile sinks to travel through the network and...

Researchers have recently exploited the use of mobile sinks in WSN and shown its potential benefits in energy savings. In order to maximize these savings and meet other QoS requirements, the mobile sink should collect all the data from the sensors during its limited contact time. This necessitate the provisioning of appropriate mechanisms to improv...

In this paper we are focusing on closed MANETs where only authorized nodes are supposed to access the network. We denote “outsider” nodes as those nodes that are not authorized to access the network, and ‘insider” nodes as those that are. The objective of this research is to develop mechanisms that protect a closed MANET against malicious behavior...

We start with role-based trust management (RBTM) and address some of the challenges associated with using RBTM in mobile ad hoc networks (MANETs). We then enhance RBTM with reputation systems (RSs), and propose a new hybrid trust management system (HTMS). In HTMS, the privilege level of an entity is determined not only by its role in the system, bu...

We present a distributed verification algo- rithm to check the existence of multiple disjoint paths between all nodes in a wireless network. In contrast to the expensive algorithms computing full disjoint paths between nodes, our proposed algorithm distributes the computation across the network and makes statements regarding the interconnectedness...

Automatic IP Multicast Without Explicit Tunnels (AMT) has recently been proposed as an enabling technology to expand multicast content availability in the Internet. Using AMT, clients in unicast-only networks can establish tunnels to AMT relay servers to receive multicast content over unicast-only networks. In this paper, we study the task of mappi...

Many-to-one traffic pattern in wireless sensor networks (WSNs) causes significant performance degradation toward the sink. To mitigate this so called funneling phenomenon, researchers have proposed various mechanisms at different layers. In this paper, we consider batch forwarding or packet concatenation at network layer, and experimentally demonst...

Reliable data transfer (RDT) is one of the key issues in wireless sensor networks (WSNs) and can be achieved by using link-level re-transmissions and multi-path routing. Another key issue is the scalability of WSNs. In this paper, we try to better understand and characterize/quantify the relationships between reliability and scalability, and identi...

Being an important and yet a challenging problem, the QoS-based routing in the converging Internet has received significant attention from the research community. However, most of the QoS-based routing research is conducted in the context of intra-domain routing, leaving QoS-based inter-domain routing relatively open. In this paper, we focus on QoS...

This chapter discusses the issues faced when trying to train SVM on imbalanced datasets. The main reason why SVM performs poorly for such datasets is because of the weakness of soft margins. Soft margins were introduced in order to make SVM resilient against nonseparable datasets. The idea was to tolerate some classification error as a trade off fo...

An organization consists of many resources and entities who want to access those resources. Not all entities are granted full access rights to every resource, so there must be a Trust Management System (TMS) in place to enforce access rights. In this paper, we present a new Hybrid Trust Management System (HTMS) that combines Role Based Trust Manage...

Digital signatures are mainly used to make the receiver believe that the message was actually sent by the claimed sender. However, since generating digital signatures requires intensive computations, researchers proposed batch signing systems to sign multiple messages at once while having almost the same cost of signing one message. In this paper,...

Video streaming over peer-to-peer networks has received significant attention recently. Accordingly, much work is done on video streaming under the assumption that all the peers have the whole movie. However, it is likely that many peers may only store a fraction of the movie due to their resource constraints. Therefore, there is a need to develop...

Many networks, such as P2P networks, MANETs, file sharing networks, and online auction networks rely on node cooperation. If a malicious node gains access to such a network it can easily launch attacks, such as spreading viruses or spam, or attacking known vulnerabilities. Reputation systems (RS) defend against malicious nodes by observing their pa...

In mobile ad hoc networks (MANETs) and wireless sensor networks (WSNs), it is easy to launch various sophisticated attacks such as wormhole, man-in-the-middle and denial of service (DoS), or to impersonate another node. To combat such attacks from outsider nodes, we study packet authentication in wireless networks and propose a hop-by-hop, efficien...

Reputation systems (RS) are designed to detect malicious nodes in a network and thwart their attacks, such as the spreading of viruses or worms, or attacking known vulnerabilities. They do this by collecting information about past transactions of a node and utilizing that to predict its future behavior. Traditionally, RSs have been designed by manu...

We propose a fully distributed MAC-layer priority scheduling mechanism, called LPT-DPS (Lower-Priority-Triggered Distributed Priority Scheduling), for wireless ad hoc networks. LPT-DPS can allocate channel bandwidth to flows with different priorities in such a way that the higher the priority level of the flow, the higher the bandwidth that the flo...

During the last two decades, several value-added services (e.g., IP multicast, IP traceback, etc.) have been proposed to extend the functional capabilities of the Internet. Due to the increasing role of these services, there is a need to better understand their impact on the network. In this paper, we present an experimental study on the intersecti...

We study quality-of-service (QoS) routing, particularly two additive-constrained path selection problem, in the presence of inaccurate state information. We formulate this problem as Most-Probable Two-Additive-Constrained Path (MP-TACP) problem. To solve it, we follow a probabilistic approach and propose an algorithm called MP-TACPA. In general, MP...

In Mobile Ad-hoc Networks (MANETs), it is easy to launch various sophisticated attacks such as wormhole, man-in-the-middle and Denial of Service (DoS), or to impersonate another node. To combat such attacks from outsider nodes, we study packet authentication in wireless networks and propose a Hop-by-hop, Efficient Authentication Protocol, called HE...

Denial-of-Service (DoS) attacks commonly use IP spoofing to hide the identity and the location of the attack origin. To defend against various DoS attacks and make the attacker accountable, it is necessary to trace IP packets regardless of their source addresses. In this direction, log-based IP traceback is a promising and powerful approach due to...

Securing Wireless Sensor Networks (WSNs) against attacks is crucial in order to deploy them across a broad range of applications. It is easy for adversaries to launch sophisticated attacks against them such as wormhole, man-in-the-middle and Denial of Service (DoS), or to impersonate other sensors and send false information. We present a new packet...

Multi-constrained path (MCP) selection is one of the great challenges that QoS routing (QoSR) faces. To address it in an efficient and highly responsive manner, we propose a new QoSR algorithm, namely NM_MCP (normal measure-based multiple constrained path). Using the Dijkstra’s algorithm with respect to each link metric, NM_MCP pre-computes k prima...

We consider the problem of minimizing the differential delay in a virtually concatenated Ethernet-over-SONET (EoS) system by suitable path selection. In such a system, a service provider can dynamically add virtual channels to or drop them from a Virtually Concatenated Group (VCG). A new virtual channel can be added to the VCG provided that the dif...

We focus on the algorithmic aspect of selecting a path that minimizes a recently proposed nonlinear path metric (namely, WCETT) for providing high throughput in multi-radio, multihop wireless mesh networks. First, we consider an iterative line search technique and describe how to use it for finding the optimal path in some cases while finding appro...

Being an important and yet a challenging problem, the QoS-based routing in the converging Internet has received significant attention from the research community. However, most of the QoS-based routing research is conducted in the context of intra-domain routing, leaving QoS-based inter-domain routing relatively open. In this paper, we specifically...

This paper focuses on understanding the scale and the distribution of "state overhead'' (briefly load) that is incurred on the routers by various value-added network services, e.g., IP multicast and IP traceback. This understanding is essential to developing appropriate mechanisms and provisioning resources so that the Internet can support such val...

Ethernet over SONET (EoS) is a popular approach for interconnecting geographically distant Ethernet segments using a SONET transport infrastructure. It typically uses virtual concatenation (VC) for dynamic bandwidth management. The aggregate SONET bandwidth that supports a given EoS system is obtained by "concatenating" a number of virtual channels...

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In this paper, we study quality-of-service (QoS) routing, particularly two additive-constrained path problem, in the presence of inaccurate state information. We formulate this problem as most-probable two-additive-constrained path (MP-TACP) problem. To solve it, we follow a probabilistic approach and propose an algorithm called MP-TACPA. In genera...

Verifying physical presence of a neighbor in wireless ad hoc networks is one of the key components in developing protocols resilient to replay-based attacks. For this, we first consider RTT-based and power-based approaches. We then couple them to design an effective neighbor verification protocol (NVP). In theory, we always see some room for replay...

Multi-constrained path (MCP) selection is one of the great challenges that QoS routing (QoSR) faces. To address it in an efficient and highly responsive manner, we propose a new QoSR algorithm, namely NM_MCP. Using the Dijkstra’s algorithm with respect to each link metric, NM_MCP pre-computes k primary paths, where k is the number of link weights....

One of the challenging issues in QoS routing (QoSR) is how to select a multi-constrained path (MCP) that can meet the QoS requirements. We consider the concept of Pareto optimality in the context of MCP problems and establish a Pareto optimal based partition framework (POPF). Based on the key concepts in POPF, we propose algorithm (DA_2CP) to deal...

Tracing IP packets to their sources, known as IP traceback, is an important task in defending against IP spoofing and DoS attacks. Log-based IP traceback technique is to log packets at routers in the network and then determine the network paths which packets traversed using data extraction techniques. The biggest advantage of log-based IP traceback...

We consider the problem of minimizing the differential delay in a virtually concatenated Ethernet over SONET (EoS) system by suitable path selection. The link capacity adjustment scheme (LCAS) enables network service providers to dynamically add STS-n channels to or drop them from a virtually concatenated group (VCG). A new STS-n channel can be add...

Current link-state routing protocols (e.g., OSPF) use flooding to disseminate link-state information throughout the network. Despite its simplicity and reliability, flooding incurs unnecessary communication and processing overheads in control plane since nodes may receive multiple copies of the same advertisement. These overheads become significant...

Constraint-based path selection is an invaluable part of a full-fledged quality of service (QoS) architecture. Internet service providers want to be able to select paths for QoS flows that optimize network utilization and satisfy user requirements and as such increase revenues. Unfortunately, finding a path subject to multiple constraints is known...

The modern world is increasingly dependent on software, and yet the software we use is often manifestly insecure and unreliable. It seems only a matter of time until a "cyber-Pearl harbor" occurs. As a result, we can expect future systems to be programmed ...

We introduce a new "state-path decoupled QoS-based routing framework" (SPD-QRF) in which path computation and the dynamics of network state information along the computed paths are considered in a decoupled manner. Basically, SPD-QRF first makes several (potentially feasible) paths be readily available throughout the network(s) by marking the outgo...

Constraint-based routing is an invaluable part of a full- fledged Quality of Service architecture. Unfortunately, QoS routing with multiple additive constraints is known to be a NP-complete problem. Hence, accurate constraint-based routing algorithms with a fast running time are scarce, perhaps even non-existent. The need for such algorithms has re...

One of the challenging issues in exchanging multimedia information over a network is how to determine a feasible path that satisfies all the quality-of-service (QoS) requirements of multimedia applications while maintaining high utilization of network resources. The latter objective implies the need to impose an additional optimality requirement on...

A key issue in any QoS routing framework is how to compute a path that satisfies given QoS constraints. We focus on the path computation problem subject to bandwidth and delay constraints. This problem can be solved easily if the exact state information is available to the node computing the path. In practice, nodes have only imprecise knowledge of...

Ramsey Theory studies the existence of highly regular patterns within a large system or a set of randomly selected points or numbers. The role of Ramsey Numbers is to quantify some of the general existential theorems in Ramsey Theory. Attempting to find ...

Constraint-based path selection aims at identifying a path that satisfies a set of quality of service (QoS) constraints. In general, this problem is known to be NP-complete, leading to the proposal of many heuristic algorithms. We provide an overview of these algorithms, focusing on restricted shortest path and multi-constrained path algorithms.

This paper mainly presents a Turkish sentence generator for producing the actual text from its semantic description. To concentrate on the text generation rather than text planning, we assume that the lexicalized semantic de- scription of the text is produced in some way, currently given by hand. In the generation, we need a linguistic theory to de...

Current link-state routing protocols (e.g., OSPF) use flooding to disseminate link-state information throughout the network. Despite its simplicity and reliability, flooding incurs unnecessary communications overhead since nodes may receive multiple copies of the same advertisement. This extra overhead becomes an Issue in the context of quality-of-...

Constraint-based routing is an invaluable part of a full-ßedged Quality of Service (QoS) archi-tecture. Unfortunately, routing with multiple additive constraints is known to be a NP-complete problem. Hence, accurate constraint-based routing algorithms with a fast running time are scarce, perhaps even non-existent. The expected impact of such a cons...

An important aspect of quality-of-service (QoS) provisioning in integrated networks is the ability to find a feasible route that satisfies a set of end-to-end QoS requirements (or constraints) while efficiently using network resources. In general, finding a path subject to multiple additive constraints (e.g., delay, delay-jitter) is an NP-complete...

This paper mainly presents a Turkish sentence generator for producing the actual text from its semantic description. To concentrate on the text generation rather than text planning, we assume that the lexicalized semantic description of the text is produced in some way, currently given by hand. In the generation, we need a linguistic theory to desc...

Providing quality-of-service (QoS) guarantees in packet networks gives rise to several challenging issues. One of them is how to determine a feasible path that satisfies a set of constraints while maintaining high utilization of network resources. The latter objective implies the need to impose an additional optimality requirement on the feasibilit...

In this paper, we investigate the problem of topology aggregation (TA) for scalable, QoS-based routing in hierarchical networks. TA is the process of summarizing the topological information of a subset of network elements. This summary is flooded throughout the network and used by various nodes to determine appropriate routes for connection request...

One of the key issues in providing end-to-end quality-of-service (QoS) guarantees in packet networks is how to determine a feasible path that satisfies a number of QoS constraints. For two or more additive constraints, the problem of finding a feasible path is NP-complete that cannot be exactly solved in polynomial time. Accordingly, several heuris...

One of the key issues in providing end-to-end quality-of-service guarantees in packet networks is how to determine a feasible route that satisfies a set of constraints while simultaneously maintaining high utilization of network resources. In general, finding a path subject to multiple additive constraints (e.g., delay, delay-jitter) is an NP-compl...

In this paper, we investigate the problem of topology aggregation (TA) for scalable, QoS-based routing in ATM networks. TA is the process of summarizing the topological information of a subset of network elements. This summary is flooded throughout the network, and is used by various nodes to determine appropriate routes for connection requests. A...

We investigate the problem of topology aggregation (TA) for scalable, QoS-based routing in ATM networks. TA is the process of summarizing the topological information of a subset of network elements. This summary is flooded throughout the network, and is used by various nodes to determine appropriate routes for connection requests. A key issue in th...

An important aspect of quality-of-service (QoS) provisioning in integrated networks is the ability to find a feasible route that satisfies end-to-end QoS requirements of a connection request while efficiently using network resources. In general, finding a path subject to multiple additive constraints (e.g., delay, delay-jitter) is an NP-complete pr...