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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14288/3
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Publication Metadata only Multi-scale deformable alignment and content-adaptive inference for flexible-rate bi-directional video compression(IEEE Computer Society, 2023) Department of Electrical and Electronics Engineering; Yılmaz, Mustafa Akın; Ulaş, Ökkeş Uğur; Tekalp, Ahmet Murat; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of EngineeringThe lack of ability to adapt the motion compensation model to video content is an important limitation of current end-to-end learned video compression models. This paper advances the state-of-the-art by proposing an adaptive motion-compensation model for end-to-end rate-distortion optimized hierarchical bi-directional video compression. In particular, we propose two novelties: i) a multi-scale deformable alignment scheme at the feature level combined with multi-scale conditional coding, ii) motion-content adaptive inference. In addition, we employ a gain unit, which enables a single model to operate at multiple rate-distortion operating points. We also exploit the gain unit to control bit allocation among intra-coded vs. bi-directionally coded frames by fine tuning corresponding models for truly flexible-rate learned video coding. Experimental results demonstrate state-of-the-art rate-distortion performance exceeding those of all prior art in learned video coding1.Publication Metadata only Virtual collaboration tools for mixed-ability workspaces: a cross disability solidarity case from Turkey(Assoc Computing Machinery, 2023) Department of Media and Visual Arts; Yıldız, Zeynep; Subaşı, Özge; Department of Media and Visual Arts; Graduate School of Social Sciences and HumanitiesA growing body of literature on mixed-ability teams within HCI investigates how disabled and non-disabled people collaborate. Still, how diferent disabilities can interact in a mixed-ability team is underexplored, especially for long commitments and in non-western contexts. As an emerging perspective in accessibility studies in HCI, disability justice emphasizes the importance of cross-disability collaborations. Collaborative access, interdependence, and crossdisability dialogue are keys to building accessible mixed-ability interactions. We conducted ten in-depth interviews with the members of a unique mixed-ability team (which includes people with diferent physical disabilities) using the same workspace with crossdisability interactions in Turkey. We aim to understand the requirements for an accessible mixed-ability virtual workspace and to identify practical design considerations for cross-disability solidarityoriented virtual collaboration tools. To ensure equal access in virtual workspaces, we suggest implications for centering collective access, balancing external power dynamics, and supporting language and cultural diversities.Publication Metadata only Ris-aided angular-based hybrid beamforming design in mmwave massive mimo systems(IEEE, 2022) Koc, Asil; Tho Le-Ngoc; Department of Electrical and Electronics Engineering; Yıldırım, İbrahim; Başar, Ertuğrul; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of EngineeringThis paper proposes a reconfigurable intelligent surface (RIS)-aided and angular-based hybrid beamforming (AB-HBF) technique for the millimeter wave (mmWave) massive multiple-input multiple-output (MIMO) systems. The proposed RIS-AB-HBF architecture consists of three stages: (i) RF beam-former, (ii) baseband (BB) precoder/combiner, and (iii) RIS phase shift design. First, in order to reduce the number of RF chains and the channel estimation overhead, RF beamformers are designed based on the 3D geometry-based mmWave channel model using slow time-varying angular parameters of the channel. Second, a BB precoder/combiner is designed by exploiting the reduced-size effective channel seen from the BB stages. Then, the phase shifts of the RIS are adjusted to maximize the achievable rate of the system via the nature-inspired particle swarm optimization (PSO) algorithm. Illustrative simulation results demonstrate that the use of RISs in the AB-HBF systems has the potential to provide more promising advantages in terms of reliability and flexibility in system design.Publication Metadata only Snoopie: a multi-GPU communication profiler and visualizer(Assoc Computing Machinery, 2024) Department of Computer Engineering; Issa, Mohammad Kefah Taha; Sasongko, Muhammad Aditya; Turimbetov, İlyas; Baydamirli, Javid; Sağbili, Doğan; Erten, Didem Unat; Department of Computer Engineering; Graduate School of Sciences and Engineering; College of EngineeringWith data movement becoming one of the most expensive bottlenecks in computing, the need for profiling tools to analyze communication becomes crucial for effectively scaling multi-GPU applications. While existing profiling tools including first-party software by GPU vendors are robust and excel at capturing compute operations within a single GPU, support for monitoring GPU-GPU data transfers and calls issued by communication libraries is currently inadequate. To fill these gaps, we introduce Snoopie, an instrumentation-based multi-GPU communication profiling tool built on NVBit, capable of tracking peer-to-peer transfers and GPU-centric communication library calls. To increase programmer productivity, Snoopie can attribute data movement to the source code line and the data objects involved. It comes with multiple visualization modes at varying granularities, from a coarse view of the data movement in the system as a whole to specific instructions and addresses. Our case studies demonstrate Snoopie's effectiveness in monitoring data movement, locating performance bugs in applications, and understanding concrete data transfers abstracted beneath communication libraries. The tool is publicly available at https://github.com/ParCoreLab/snoopie.Publication Metadata only Mind the whisper: enriching collocated social interactions in public places through audio narratives(Assoc Computing Machinery, 2022) Department of Media and Visual Arts; Genç, Hüseyin Uğur; Erdem, Duru; Yıldırım, Çaǧla; Coşkun, Aykut; Department of Media and Visual Arts; KU Arçelik Research Center for Creative Industries (KUAR) / KU Arçelik Yaratıcı Endüstriler Uygulama ve Araştırma Merkezi (KUAR); Graduate School of Social Sciences and Humanities; College of Social Sciences and HumanitiesThe quality of social interaction has great importance for psychological and physiological health. Previous research indicates that smartphones have adverse effects on collocated social interactions. Most HCI works addressed this issue by restricting smartphone use during social interactions. Diverging from previous work, we designed WHISPER, an audio narrative box that aims to enrich collocated social interactions without restricting mobile technology use. We conducted a user study in a cafe environment with 21 participants to understand how users react to WHISPER and how it would influence their social interactions. In this paper, we present the result of this study and discuss four implications for technologies designed to enhance collocated social interactions (Respectfulness, Balanced Ambiguity, Adaptability, and Being Targeted) and two implications for research touching upon the HCI work on Design for Behavior Change and Collocated Interactions (Designing responsible interventions for accommodating unintended outcomes and Quantifying the quality of social interactions).Publication Metadata only Eliciting parents' insights into products for supporting and tracking children's fine motor development(Assoc Computing Machinery, 2022) Department of Psychology;Department of Media and Visual Arts; Gürbüzsel, İpek; Göksun, Tilbe; Coşkun, Aykut; KU Arçelik Research Center for Creative Industries (KUAR) / KU Arçelik Yaratıcı Endüstriler Uygulama ve Araştırma Merkezi (KUAR); Graduate School of Social Sciences and Humanities; College of Social Sciences and HumanitiesEarly development of fine motor skills is a critical milestone for children, which also helps the formation and maturation of other developmental areas like language development. While toys and daily artefacts could support children's fine motor skills, parents play a profound role in monitoring their developmental progress. Although there are several products to support fine motor development and help parents monitor their children's progress, the literature lacks a source that might inform the design of such products. As the first step of a bigger research project, we conducted semi-structured interviews with 13 parents to gather their insights into and expectations of such supportive products. We designed a sensor-embedded toy concept, ANIMO, aimed at supporting the fine motor development of 7 to 24-month-old children and assisting parents in tracking their children's developmental progress via a mobile app. We showed this concept to parents during interviews to facilitate the insight elicitation process. We present ANIMO, three themes summarizing parents' insights and expectations into products supporting fine motor development along with implications for their design.Publication Metadata only Designing physical objects for young children's magnitude understanding: a TUI research through design journey(Assoc Computing Machinery, 2022) Department of Psychology;Department of Media and Visual Arts; Beşevli, Ceylan; Göksun, Tilbe; Özcan, Oğuzhan; KU Arçelik Research Center for Creative Industries (KUAR) / KU Arçelik Yaratıcı Endüstriler Uygulama ve Araştırma Merkezi (KUAR); Graduate School of Social Sciences and Humanities; College of Social Sciences and HumanitiesMagnitude understanding, an understudied topic in Child-Computer Interaction, entails making nonsymbolic ' moreless' comparisons that influence young children's later math and academic achievements. To support this ability, designing tangible user interfaces ( TUIs) demands considering many facets, ranging from elements within the physical world to the digital design components. This multifaceted activity brings many design decisions often not reflected in research. Therefore, we present this reflection via our research through design process in developing a vital design element, the physical form. We share our (i) physical object design criteria elicitation for magnitude understanding, (ii) hands- on making process, and (iii) preliminary studies with children engaging with objects. With our insights obtained through these steps, we project how this physical object-initiated research inspires the TUI in the upcoming steps and present design takeaways for CCI researchers.Publication Metadata only GPU-initiated resource allocation for irregular workloads(Assoc Computing Machinery, 2024) Department of Computer Engineering; Turimbetov, İlyas; Sasongko, Muhammad Aditya; Erten, Didem Unat; Department of Computer Engineering; College of EngineeringGPU kernels may suffer from resource underutilization in multi-GPU systems due to insufficient workload to saturate devices when incorporated within an irregular application. To better utilize the resources in multi-GPU systems, we propose a GPU-sided resource allocation method that can increase or decrease the number of GPUs in use as the workload changes over time. Our method employs GPU-to-CPU callbacks to allowGPU device(s) to request additional devices while the kernel execution is in flight. We implemented and tested multiple callback methods required for GPU-initiated workload offloading to other devices and measured their overheads on Nvidia and AMD platforms. To showcase the usage of callbacks in irregular applications, we implemented Breadth-First Search (BFS) that uses device-initiated workload offloading. Apart from allowing dynamic device allocation in persistently running kernels, it reduces time to solution on average by 15.7% at the cost of callback overheads with a minimum of 6.50 microseconds on AMD and 4.83 microseconds on Nvidia, depending on the chosen callback mechanism. Moreover, the proposed model can reduce the total device usage by up to 35%, which is associated with higher energy efficiency.Publication Metadata only Designing for data sensemaking practices: a complex challenge(Association for Computing Machinery, 2024) Karahanoǧlu, Armaǧan; Department of Media and Visual Arts; Coşkun, Aykut; Department of Media and Visual Arts; College of Social Sciences and HumanitiesThe framework we presented here is a way to explain how self-trackers make sense of their data, translating them from numbers into meaningful insights. Understanding the data sensemaking process, however, is only the first step in designing for data sensemaking. Developing a new generation of tools that support individuals’ sensemaking practices is a significant challenge.Publication Metadata only A novel reconfigurable intelligent surface-supported code index modulation-based receive spatial modulation system(IEEE-Institute of Electrical and Electronics Engineers, 2024) Ozden, Burak Ahmet; Cogen, Fatih; Aydin, Erdogan; Ilhan, Haci; Wen, Miaowen; Department of Electrical and Electronics Engineering; Başar, Ertuğrul; Department of Electrical and Electronics Engineering; College of EngineeringToday's wireless communication networks have many requirements such as high data rate, high reliability, low latency, low error data transmission, and high energy efficiency. High-performance index modulation (IM) techniques and reconfigurable intelligent surface (RIS) technology, which has recently attracted the attention of researchers, are strong candidates to meet these requirements. This paper introduces a novel RIS-supported code IM-based receive spatial modulation (RIS-CIM-RSM) system. The proposed RIS-CIM-RSM system uses quadrature amplitude modulation (QAM) symbols, receive antenna indices, and spreading code indices for wireless data transmission. In the proposed system, an RIS applies a phase rotation that maximizes signal-to-noise ratio (SNR) to the signals coming to the reflecting elements and directs them to the selected receive antenna. Performance analyses of the proposed RIS-CIM-RSM system such as data rate, throughput, and energy saving are obtained. The results obtained show that the proposed RIS-CIM-RSM system is superior to the counterpart RIS-based IM systems in the literature in terms of data rate, throughput, energy saving, and error performance.