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Publication Metadata only A novel economic-based scheduling heuristic for computational grids(Sage Publications Ltd, 2007) N/A; Department of Computer Engineering; Sönmez, Ömer Ozan; Gürsoy, Attila; Master Student; Faculty Member; Department of Computer Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; 8745In the economic-based computational grids we need effective schedulers not only to minimize the makespan but also to minimize the costs that are spent for the execution of the jobs. in this work, A novel economy driven job scheduling heuristic is proposed and a simulation application is developed by using GridSim toolkit to investigate the performance of the heuristic. the simulation-based experiments demonstrate the effectiveness of the proposed heuristic both in terms of parameter sweep and sequential workflow type of applications.Publication Metadata only Data-driven abnormal behavior detection for autonomous platoon(IEEE Computer Society, 2018) N/A; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Uçar, Seyhan; Ergen, Sinem Çöleri; Özkasap, Öznur; PhD Student; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; 7211; 113507Autonomous platoon is a technique where co-operative adaptive cruise control (CACC) enabled vehicles are organized into groups of close following vehicles through communication. It is envisioned that with the increased demand for autonomous vehicles, platoons would be a part of our life in near future. Although many efforts have been devoted to implement the vehicle platooning, ensuring the security remains challenging. Due to lack of security, platoons would be subject to modified packets which can mislead the platoon and result in platoon instability. Therefore, identifying malicious vehicles has become an important requirement. In this paper, we investigate a data-driven abnormal behavior detection approach for an autonomous platoon. We propose a novel statistical learning based technique to detect data anomalies. We demonstrate that shared speed value among platoon members would be sufficient to detect the misbehaving vehicles.Publication Metadata only Detection of food intake events from throat microphone recordings using convolutional neural networks(Institute of Electrical and Electronics Engineers (IEEE), 2018) N/A; Department of Computer Engineering; Turan, Mehmet Ali Tuğtekin; Erzin, Engin; PhD Student; Faculty Member; Department of Computer Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; 34503Food intake analysis is a crucial step to develop an automated dietary monitoring system. Processing of eating sounds deliver important cues for the food intake monitoring. Recent studies on detection of eating activity generally utilize multimodal data from multiple sensors with conventional feature engineering techniques. In this study, we target to develop a methodology for detection of ingestion sounds, namely swallowing and chewing, from the recorded food intake sounds during a meal. Our methodology relies on feature learning in the frequency domain using a convolutional neural network (CNN). Spectrograms extracted from the recorded food intake sounds through a laryngeal throat microphone are fed in to the CNN architecture. Experimental evaluations are performed on our in-house food intake dataset, which includes 8 subject, 10 different food types covering 276 minutes of recordings. The proposed system attains high detection rates of the swallow and chew events with high sensitivity and specificity, and delivers a potential for food intake monitoring under daily life conditions in future studies.Publication Metadata only Dimming support for visible light communication in intelligent transportation and traffic system(Ieee, 2016) N/A; N/A; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Department of Electrical and Electronics Engineering; Uçar, Seyhan; Turan, Buğra; Ergen, Sinem Çöleri; Özkasap, Öznur; Ergen, Mustafa; PhD Student; PhD Student; Faculty Member; Faculty Member; Faculty Member; Department of Computer Engineering; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; College of Engineering; N/A; N/A; 7211; 113507; N/AThe automotive industry is under a major change and new vehicles are being enriched by the recent advances in communication. Not only business plans are changing due to connected and urbanized lifestyle, but also transportation is becoming more intelligent with smart roads that connect smart cars. Technology coined as the vehicular ad-hoc network (VANET) is harmonizing with Intelligent Transportation System (ITS) and Intelligent Traffic System (ITF). However, ITS and ITF systems suffer from the scarcity of radio frequency spectrum. Visible light communication (VLC) that uses modulated optical radiation in the visible light spectrum is an alternative medium being researched. To date, the majority of research on vehicular VLC was aimed at achieving high data rates provided that high lighting quality is achieved without any concern on dimmable LED lights. Auto-dimmable headlights gain attention due to danger caused by sudden glare on drivers at night conditions which makes dimming in VLC necessary. In this paper, we first present the latest concept of vehicular VLC on ITS and ITF systems and address dimming utility. We then demonstrate experimentally that dimming is a key parameter in VLC which affects data dissemination and received power signal strength.Publication Metadata only Dimming support for visible light communication in intelligent transportation and traffic system(Institute of Electrical and Electronics Engineers (IEEE), 2016) N/A; N/A; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Department of Electrical and Electronics Engineering; Uçar, Seyhan; Turan, Buğra; Ergen, Sinem Çöleri; Özkasap, Öznur; Ergen, Mustafa; PhD Student; PhD Student; Faculty Member; Faculty Member; Faculty Member; Department of Computer Engineering; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; College of Engineering; N/A; N/A; 7211; 113507; N/AThe automotive industry is under a major change and new vehicles are being enriched by the recent advances in communication. Not only business plans are changing due to connected and urbanized lifestyle, but also transportation is becoming more intelligent with smart roads that connect smart cars. Technology coined as the vehicular ad-hoc network (VANET) is harmonizing with Intelligent Transportation System (ITS) and Intelligent Traffic System (ITF). However, ITS and ITF systems suffer from the scarcity of radio frequency spectrum. Visible light communication (VLC) that uses modulated optical radiation in the visible light spectrum is an alternative medium being researched. To date, the majority of research on vehicular VLC was aimed at achieving high data rates provided that high lighting quality is achieved without any concern on dimmable LED lights. Auto-dimmable headlights gain attention due to danger caused by sudden glare on drivers at night conditions which makes dimming in VLC necessary. In this paper, we first present the latest concept of vehicular VLC on ITS and ITF systems and address dimming utility. We then demonstrate experimentally that dimming is a key parameter in VLC which affects data dissemination and received power signal strength.Publication Open Access Investigating contributions of speech and facial landmarks for talking head generation(International Speech Communication Association (ISCA), 2021) N/A; Department of Computer Engineering; Kesim, Ege; Erzin, Engin; Faculty Member; Department of Computer Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; 34503Talking head generation is an active research problem. It has been widely studied as a direct speech-to-video or two stage speech-to-landmarks-to-video mapping problem. In this study, our main motivation is to assess individual and joint contributions of the speech and facial landmarks to the talking head generation quality through a state-of-the-art generative adversarial network (GAN) architecture. Incorporating frame and sequence discriminators and a feature matching loss, we investigate performances of speech only, landmark only and joint speech and landmark driven talking head generation on the CREMA-D dataset. Objective evaluations using the peak signal-to-noise ratio (PSNR), structural similarity index (SSIM) and landmark distance (LMD) indicate that while landmarks bring PSNR and SSIM improvements to the speech driven system, speech brings LMD improvement to the landmark driven system. Furthermore, feature matching is observed to improve the speech driven talking head generation models significantly.Publication Metadata only Mixed and multi-precision SpMV for GPUs with row-wise precision selection(IEEE Computer Society, 2022) Kaya, Kamer; N/A; N/A; N/A; Department of Computer Engineering; Tezcan, Erhan; Torun, Tuğba; Koşar, Fahrican; Erten, Didem Unat; Master Student; Researcher; Master Student; Faculty Member; Department of Computer Engineering; Graduate School of Sciences and Engineering; N/A; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; N/A; 219274Sparse Matrix-Vector Multiplication (SpMV) is one of the key memory-bound kernels commonly used in industrial and scientific applications. To improve its data movement and benefit from higher compute rates, there are several efforts to utilize mixed precision on SpMV. Most of the prior-art focus on performing the entire SpMV in single-precision within a bigger context of an iterative solver (e.g., CG, GMRES). In this work, we are interested in a more fine-grained mixed-precision SpMV, where the level of precision is decided for each element in the matrix to be used in a single operation. We extend an existing entry-wise precision based approach by deciding precisions per row, motivated by the granularity of parallelism on a GPU where groups of threads process rows in CSR-based matrices. We propose mixed-precision CSR storage methods with row permutations and describe their greater efficiency and load-balancing compared to the existing method. We also consider a multi-precision case where single and double precision copies of the matrix are stored priorly and further extend our mixed-precision SpMV approach to comply with it. As such, we leverage a mixed-precision SpMV to obtain a multi-precision Jacobi method which is faster than yet almost as accurate as double-precision Jacobi implementation, and further evaluate a multi-precision Cardiac modeling algorithm. We demonstrate the effectiveness of the proposed SpMV methods on an extensive dataset of real-valued large sparse matrices from the SuiteSparse Matrix Collection using an NVIDIA V100 GPU.Publication Metadata only Online client assignment in dynamic real-time distributed interactive applications(Ieee, 2013) N/A; N/A; Department of Computer Engineering; Uçar, Seyhan; Güler, Hüseyin; Özkasap, Öznur; PhD Student; PhD Student; Faculty Member; Department of Computer Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; 113507Qulaity of user experience in Distributed Interactive Applications (DIAs) highly depends on the network latencies during the system execution. In DIAs, each user is assigned to a server and communication with any other client is performed throught its assigned server. Hence, latency measured between two clients, called interaction time, consists of two components. One is the latency between the client and its assigned server, and the other is the inter-server latency, that is the latency between servers that the clients are assigned. In this paper, we investigate a real-time client to server assignment scheme in a DIA where the objective is to minimize the interaction time among clients. The client assignment problem is known to be NP-complete and heuristics play an important role in finding near optimal solutions. We propose two distributed heuristic algorithms to the online client assignment problem in a dynamic DIA system. We utilized real-time Internet latency data on PlanetLab platform and performed extensive 3 experiments using geographically distributed PlanetLab nodes where nodes can arbitrarily join/leave the system. The experimental results demonstrate that our proposed algorthims can reduce the maximum interaction time among clients up to 45% compared to an exiting baseline technique.Publication Metadata only Reusetracker: fast yet accurate multicore reuse distance analyzer(Assoc Computing Machinery, 2022) Chabbi, Milind; Department of Computer Engineering; N/A; Department of Computer Engineering; Sasongko, Muhammad Aditya; Marzijarani, Mandana Bagheri; Erten, Didem Unat; Researcher; Master Student; Faculty Member; Department of Computer Engineering; College of Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; 219274One widely used metric that measures data locality is reuse distance-the number of unique memory locations that are accessed between two consecutive accesses to a particular memory location. State-of-the-art techniques that measure reuse distance in parallel applications rely on simulators or binary instrumentation tools that incur large performance and memory overheads. Moreover, the existing sampling-based tools are limited to measuring reuse distances of a single thread and discard interactions among threads in multi-threaded programs. In this work, we propose REUSETRACKER a fast and accurate reuse distance analyzer that lever-ages existing hardware features in commodity CPUs. REUSETRACKER is designed for multi-threaded programs and takes cache-coherence effects into account. By utilizing hardware features like performance monitoring units and debug registers, REUSETRACKER can accurately profile reuse distance in parallel applications with much lower overheads than existing tools. It introduces only 2.9x runtime and 2.8x memory overheads. Our tool achieves 92% accuracy when verified against a newly developed configurable benchmark that can generate a variety of different reuse distance patterns. We demonstrate the tool's functionality with two use-case scenarios using PARSEC, Rodinia, and Synchrobench benchmark suites where REUSETRACKER guides code refactoring in these benchmarks by detecting spatial reuses in shared caches that are also false sharing and successfully predicts whether some benchmarks in these suites can benefit from adjacent cache line prefetch optimization.Publication Metadata only Security vulnerabilities of IEEE 802.11p and visible light communication based platoon(IEEE Computer Society, 2016) N/A; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Uçar, Seyhan; Ergen, Sinem Çöleri; Özkasap, Öznur; PhD Student; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; 7211; 113507Technology brings autonomous vehicles into the reality where vehicles become capable of cruising themselves. A vehicular platoon contains autonomous vehicles organized into groups with close proximity. It is envisioned that with the increased demand for autonomous vehicles, platoons would be the part of our lives in near future. From this perspective, vehicular platoon control using current dominant IEEE 802.11p (DSRC) is an active research field. However, DSRC suffers from problems of performance degradation due to congestion, the scarcity of radio-frequency (RF) and security. Visible Light Communication (VLC), on the other hand, is a promising complementary technology with the potential to address DSRC problems. In this paper, we investigate the security vulnerabilities of hybrid DSRC-VLC platoon in the presence of outside attackers. We develop a simulation platform to realize the hybrid platoon. We demonstrate that although VLC limits the effect of adversaries, hybrid architectures still suffer from the packet falsification and replay attacks.