Hamed Alimohammadzadeh

dblp:348/8107 · DBLP profile ↗
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6ranked-venue papers
6as first author
6since 2021 · last 2026
0000-0003-2613-5010ORCID · corroborated

Domains — the database's venue-derived domains; a paper can count in several

Graphics, computer vision, multimedia, augmented reality and games · 6 · 6 first-author · 6 since 2021Computer networks · 1 · 1 first-author · 1 since 2021Databases, data management, data science and information retrieval · 1 · 1 first-author · 1 since 2021
YearPublicationVenuePosition
2026 Techniques to Conceal Dark Standby Flying Light Specks
abstract
A Flying Light Speck (FLS) is a small drone configured with light sources to illuminate different colors and textures. A swarm of FLSs illuminates complex 3D multimedia shapes in a fixed volume, a 3D display. An FLS is a mechanical device. Its failure is the norm rather than an exception, causing a point of an illumination to go dark. In this article, we use reliability groups with dark standby FLSs to minimize the duration of time a point remains dark. We introduce three techniques to prevent a dark standby FLS from obstructing the user’s Field of View (FoV). All three move the FLS out of the user’s FoV. One technique, Suspend:Closest, maximizes the utility of a standby FLS while preventing it from obstructing the user’s FoV.
Hamed Alimohammadzadeh, Shuqin Zhu, Shahram Ghandeharizadeh
ACM Trans. Multim. Comput. Commun. Appl.1
2025 Reproducibility Companion Paper: Swarical: An Integrated Hierarchical Approach to Localizing Flying Light Specks
abstract
This companion paper provides artifacts and instructions on replicating the experiments in the ACM Multimedia 2024 paper entitled ''Swarical: An Integrated Hierarchical Approach to Localizing Flying Light Specks.'' Swarm-based hierarchical, Swarical, is a localization technique that enables miniature drones, Flying Light Specks (FLSs), to accurately and efficiently localize and illuminate complex 2D and 3D shapes. It consists of two components, an offline planner and an online localization technique that executes on an FLS. The offline planner uses the FLS sensor specification for positioning to convert mesh files into swarms of FLSs. Some FLSs are dark and used only for localization. We reported the online localization technique to be fast and highly accurate. We describe how to reproduce this finding using our artifacts.
Hamed Alimohammadzadeh, Shahram Ghandeharizadeh, Federico Cunico, Joshua Springer
ACM Multimedia1
2024 Swarical: An Integrated Hierarchical Approach to Localizing Flying Light Specks
abstract
Swarical, a Swar m-based hierarchical localization technique, enables miniature drones, Flying Light Specks (FLSs), to accurately and efficiently localize and illuminate complex 2D and 3D shapes. Its accuracy depends on the physical hardware (sensors) of FLSs used to track neighboring FLSs to localize themselves. It uses the specification of the sensors to convert mesh files into point clouds that enable a swarm of FLSs to localize at the highest accuracy afforded by their sensors. Swarical considers a heterogeneous mix of FLSs with different orientations for their tracking sensors, ensuring a line of sight between a localizing FLS and its anchor FLS. We present an implementation using Raspberry cameras and ArUco markers. A comparison of Swarical with a state of the art decentralized localization technique shows that it is as accurate and more than 2x faster.
Hamed Alimohammadzadeh, Shahram Ghandeharizadeh
ACM Multimedia1
2024 Reliability Groups with Standby Flying Light Specks
abstract
A Flying Light Speck, FLS, is a miniature sized drone configured with light sources to illuminate different colors and textures. A swarm of FLSs illuminates complex 3D multimedia shapes in a fixed volume, a 3D display. An FLS is a mechanical device. Its failure is the norm rather than an exception, causing a point of an illumination to go dark. In this paper, we use reliability groups with dark standby FLSs to minimize the duration of time a point remains dark. This study makes two novel contributions. First, it compares a centralized and a decentralized algorithm to form groups, demonstrating the superiority of the centralized technique. Second, it detects when the dark standby FLSs may obstruct the user's field of view and relocates them with minimal impact on their provided benefit.
Hamed Alimohammadzadeh, Shuqin Zhu, Jiadong Bai, Shahram Ghandeharizadeh
MMSys1
2023 An Evaluation of Decentralized Group Formation Techniques for Flying Light Specks
abstract
Group formation is fundamental for 3D displays that use Flying Light Specks, FLSs, to illuminate shapes and provide haptic interactions. An FLS is a drone with light sources that illuminates a shape. Groups of G FLSs may implement reliability techniques to tolerate FLS failures, provide kinesthetic haptic feedback in response to a user’s touch, and facilitate a divide and conquer approach to challenges such as localizing FLSs to render a shape. This paper evaluates four decentralized techniques to form groups. An FLS implements a technique autonomously using asynchronous communication and without a global clock. We evaluate these techniques using synthetic point clouds with known optimal solutions and real point clouds. Obtained results show a technique named Random Subset (RS) is superior when constructing small groups (G ≤ 5) while a different technique named Closest Available Neighbor First (CANF) is superior when constructing large groups (G ≥ 10).
Hamed Alimohammadzadeh, Heather Culbertson, Shahram Ghandeharizadeh
MMAsia1
2023 Modeling Illumination Data with Flying Light Specks
abstract
A Flying Light Speck, FLS, is a miniature sized drone configured with light sources. Swarms of FLSs will illuminate an object in a 3D volume, an FLS display. These illuminations and their data models are the novel contributions of this paper. We introduce a conceptual model of drone flight paths to render static, slide, and motion illuminations. We describe a physical implementation of the conceptual model using bag files. We evaluate this implementation using different lossless compression techniques. A key finding is that our bag file implementation is very compact when compared with the original point clouds. While compression reduces the size of a bag file, a combination that includes the use of both internal bag file compression (lz4 with chunks) and Gzip is not necessarily the most compact representation. We open source our software and its point cloud sequence data for use by the scientific community, see https://github.com/flyinglightspeck/FLSbagfile.
Hamed Alimohammadzadeh, Daryon Mehraban, Shahram Ghandeharizadeh
MMSys1