VLDB 2026 Research / reviewers in the wild / expert
Krithik Ranjan
dblp:319/7422
· DBLP profile ↗
12ranked-venue papers
7as first author
12since 2021 · last 2026
0000-0002-6083-6251ORCID · verified
Domains — the database's venue-derived domains; a paper can count in several
Human-computer interaction and ubiquitous computing · 11 · 7 first-author · 11 since 2021Systems, architecture and hardware · 1 · 1 since 2021Graphics, computer vision, multimedia, augmented reality and games · 1 · 1 since 2021
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | Make Your Own Game Controller! Engaging Youth with Computer Vision-driven Physical ComputingabstractPhysical computing engages learners in computational thinking through building interest-driven physical interactive projects. However, traditional electronic approaches require deep understanding of circuits and embedded systems — a challenge for young learners before meaningful engagement with computational concepts. This pictorial demo- nstrates an alternative, computer vision (CV) approach using fiducial markers and craft materials, through a workshop model where learners design custom controllers for video games. With learner stories from workshops with learners aged 10-15, and emerging themes of computational, material, and social moments, we illustrate how CV-driven physical comp-uting can be an effective, low-barrier, introduction to computing that preserves the creative learning benefits of physical computing. Krithik Ranjan, Peter Gyory, Ellen Yi-Luen Do, Clement Zheng |
Creativity & Cognition | 1 |
| 2026 | ArUcoTUI: Software Toolkit for Prototyping Tangible Interactions on Portable Flat-Panel Displays with OpenCVabstractTangible User Interfaces (TUIs) that integrate digital information with physical interaction require specialized hardware and complex calibration, limiting their adoption in portable or mobile display systems. This paper introduces ArUcoTUI, a computer vision (CV) toolkit for prototyping tangible interactions on portable screens, leveraging standard cameras and the OpenCV library. ArUcoTUI uses ArUco fiducial markers to detect physical inputs. The software toolkit offers streamlined calibration, a signal processing pipeline, and a client application that translates tangible input into structured events for use in HCI applications. Using a conventional camera in a top-down setting with a flat-panel display, we demonstrate how this toolkit supports the development of interactive surface TUIs with advanced features, including 3D spatial interaction, multi-device interaction, and actuated tangibles within applications. We describe the software implementation, which utilizes accessible hardware to support the development of these tangible interactions. We provide the results of a preliminary evaluation with users, including design implications and suggestions for future research and development. Rong-Hao Liang, Steven Houben, Krithik Ranjan, Sandra Bae, Peter Gyory, Ellen Yi-Luen Do, Clement Zheng |
TEI | 3 |
| 2026 | Why (Not) ReacTIVision: Emerging Challenges and Opportunities for Building Tangible User Interfaces with Computer Vision ToolkitsabstractOutdated Computer Vision (CV) toolkits for Tangible User Interfaces (TUI) have led to fragmented practices, diminished reproducibility, and reduced community support. This paper examines the past, present, and future trajectory of CV-TUI toolkits. Our scoping review of ACM literature (N=120) reveals a divergence between applications using the limited interactions of established toolkits like ReacTIVision and the fragmented, bespoke systems built for complex interactions, highlighting the need for advanced toolkits that enable accessible making. We found how ReacTIVision-based projects were primarily used in stationary tabletop settings with standard token events, while non-ReacTIVision projects explored unique interaction techniques in diverse configurations. Reflecting on these insights, we offer six suggestions for building the next-generation CV-TUI toolkits to support rapid prototyping of tangible interactions. This study provides the TUI community with an updated perspective to inform future research. Krithik Ranjan, Sandra Bae, Peter Gyory, Ellen Yi-Luen Do, Clement Zheng, Rong-Hao Liang |
TEI | 1 |
| 2026 | Rig-a-Doodle: Tangible Kit for Dynamic Hand-drawn Character AnimationabstractCharacter animation remains challenging for novices and children despite advances in digital tools. While recent tangible interfaces have lowered barriers by enabling creators to animate their drawings on paper, they are limited to preset animation sequences and support for only human-like characters. We present Rig-a-Doodle, a tangible kit and web application for open-ended character rigging animation, where creators can draw any character and construct a custom physical rig using everyday materials to animate it. This work-in-progress contributes a system of tangible interaction to animate hand-drawn characters by direct physical manipulation of custom rigs in real-time. We share findings from a preliminary workshop with adults to explore the kinds of expressive animation the kit enables, discover issues with interaction, and source ideas for future directions. Krithik Ranjan, Khushbu Kshirsagar, Harrison Jesse Smith, Ellen Yi-Luen Do |
TEI | 1 |
| 2026 | Studying Mobile Spatial Collaboration across Video Calls and Augmented Reality CSCW037abstractMobile video calls are widely used to share information about real-world objects and environments with remote collaborators. While these calls provide valuable visual context in real time, the experience of interacting with people and moving around a space is significantly reduced when compared to co-located conversations. Recent work has demonstrated the potential of Mobile Augmented Reality applications to enable more spatial forms of collaboration across distance. To better understand the dynamics of mobile AR collaboration and how this medium compares against the status quo, we conducted a comparative structured observation study to analyze people’s perception of space and interaction with remote collaborators across mobile video calls and AR-based calls. Fourteen pairs of participants completed a spatial collaboration task using each medium. Through a mixed-methods analysis of session videos, transcripts, motion logs, post-task exercises, and interviews, we highlight how the choice of medium influences the roles and responsibilities that collaborators take on and the construction of a shared language for coordination. We discuss the importance of spatial reasoning with one’s body, how video calls help participants “be on the same page” more directly, and how AR calls enable both onsite and remote collaborators to engage with the space and each other in ways that resemble in-person interaction. Our study offers a nuanced view of the benefits and limitations of both mediums, and we conclude with a discussion of design implications for future systems that integrate mobile video and AR to better support spatial collaboration in its many forms. Rishi Vanukuru, Krithik Ranjan, Ada Yi Zhao, David Lindero, Gunilla Berndtsson, Gregoire Phillips, Amy Banic, Mark D. Gross, Ellen Yi-Luen Do |
Proc. ACM Hum. Comput. Interact. | 2 |
| 2025 | Tangible Interfaces for Computational Tinkering
Krithik Ranjan |
TEI | 1 |
| 2025 | Physical Computing with Paper Playground: Exploring a Multimodal Platform
Krithik Ranjan, Ann Eisenberg, Brett L. Fiedler, Jesse Greenberg, Taliesin L. Smith, Emily B. Moore |
TEI | 1 |
| 2025 | Cartoonimator: A Paper-based Tangible Kit for Keyframe Animation
Krithik Ranjan, Peter Gyory, Seneca Howell, Therese Stewart, Michael L. Rivera, Ellen Yi-Luen Do |
TEI | 1 |
| 2025 | Toward personalized AI-powered recommender systems to support users' daily music choice experiences
Youngsoo Shin, Krithik Ranjan, Michael C. Kowalski |
Int. J. Hum. Comput. Stud. | 2 |
| 2023 | Cartoonimator: A Low-cost, Paper-based Animation Kit for Computational ThinkingabstractComputational thinking has been identified as an important skill for children to learn in the 21st century, and many innovative kits and tools have been developed to integrate it into children’s learning. Yet, most solutions require the use of devices like computers or other expensive hardware, thus being inaccessible to low-income schools and communities. We present Cartoonimator, a low-cost, paper-based computational kit for children to create animations and engage with computational thinking. Cartoonimator requires only paper and a smartphone to use, offering an affordable learning experience. Children can draw the scenes and characters for their animation on the paper, which is printed with computer vision markers. We developed the mobile web app to provide an interface to capture keyframes and compile them into animations. In this paper, we describe the implementation and workflow of Cartoonimator, its deployment with children at a local STEAM event, and a planned evaluation for the kit. Krithik Ranjan, Peter Gyory, Michael L. Rivera, Ellen Yi-Luen Do |
IDC | 1 |
| 2023 | DualStream: Spatially Sharing Selves and Surroundings using Mobile Devices and Augmented RealityabstractIn-person human interaction relies on our spatial perception of each other and our surroundings. Current remote communication tools partially address each of these aspects. Video calls convey real user representations but without spatial interactions. Augmented and Virtual Reality (AR/VR) experiences are immersive and spatial but often use virtual environments and characters instead of real-life representations. Bridging these gaps, we introduce DualStream, a system for synchronous mobile AR remote communication that captures, streams, and displays spatial representations of users and their surroundings. DualStream supports transitions between user and environment representations with different levels of visuospatial fidelity, as well as the creation of persistent shared spaces using environment snapshots. We demonstrate how DualStream can enable spatial communication in real-world contexts, and support the creation of blended spaces for collaboration. A formative evaluation of DualStream revealed that users valued the ability to interact spatially and move between representations, and could see DualStream fitting into their own remote communication practices in the near future. Drawing from these findings, we discuss new opportunities for designing more widely accessible spatial communication tools, centered around the mobile phone. Rishi Vanukuru, Suibi Che-Chuan Weng, Krithik Ranjan, Torin Hopkins, Amy Banic, Mark D. Gross, Ellen Yi-Luen Do |
ISMAR | 3 |
| 2022 | A Tensor Processing Framework for CPU-Manycore Heterogeneous SystemsabstractFuture CPU-manycore heterogeneous systems can provide high peak throughput by integrating thousands of simple, independent, energy-efficient cores in a single die. However, there are two key challenges to translating this high peak throughput into improved end-to-end workload performance: 1) manycore co-processors rely on simple hardware putting significant demands on the software programmer and 2) manycore co-processors use in-order cores that struggle to tolerate long memory latencies. To address the manycore programmability challenge, this article presents a dense and sparse tensor processing framework based on PyTorch that enables domain experts to easily accelerate off-the-shelf workloads on CPU-manycore heterogeneous systems. To address the manycore memory latency challenge, we use our extended PyTorch framework to explore the potential for decoupled access/execute (DAE) software and hardware mechanisms. More specifically, we propose two software-only techniques, naïve-software DAE and systolic-software DAE, along with a lightweight hardware access accelerator to further improve area-normalized throughput. We evaluate our techniques using a combination of PyTorch operator microbenchmarking and real-world PyTorch workloads running on a detailed register-transfer-level model of a 128-core manycore architecture. Our evaluation on three real-world dense and sparse tensor workloads suggests these workloads can achieve approximately 2–$6\times $performance improvement when scaled to a future 2000-core CPU-manycore heterogeneous system compared to an 18-core out-of-order CPU baseline, while potentially achieving higher area-normalized throughput and improved energy efficiency compared to general-purpose graphics processing units. Peitian Pan, Zhongyuan Zhao 0004, Krithik Ranjan, Jack Weber, Bandhav Veluri, Seyed Borna Ehsani, Max Ruttenberg, Dai Cheol Jung, Preslav Ivanov, Dustin Richmond, Michael B. Taylor, Zhiru Zhang, Christopher Batten |
IEEE Trans. Comput. Aided Des. Integr. Circuits Syst. | 4 |