13 papers
The Invisible Throttle: Running on Borrowed Time in Scratch
Xinyue Feng, Hanyuan Shi, Yuan Si
Scratch has 135 million registered users, most of them children, and 164 million shared projects. What they are taught about the speed of a script fits in one sentence: a loop iter…
The Invisible Scheduler: Dragging a Sprite Can Change What a Scratch Program Does
Xinyue Feng, Hanyuan Shi, Yuan Si
Tens of millions of children program in Scratch, whose programs are concurrent: when the green flag is clicked, every sprite's scripts start together and share the project's state.…
The Ingestion Tax: Adopting File-Backed Weights in Tensor Frameworks
Yuan Si, Yufeng Lin, Daming Li +1
Open-weight models can occupy a middle capacity regime: active weights fit in DRAM as cached file pages, but a second framework-owned copy does not fit or must be refilled as layer…
Who Should Own the Expert Cache? Kernel-Managed Tiering for Trillion-Parameter MoE Inference
Yuan Si, Yufeng Lin, Daming Li +1
Mixture-of-experts models whose expert pools exceed DRAM capacity require a weight-residency tier. Existing systems manage it in user space with expert-granular placement, frequenc…
AISPA: User-Centric System Prompt Auditing for Large Language Model Applications
Xiangning Lin, Shenzhe Zhu, Shu Yang +23
System prompts are instructions configured by developers to govern the behaviors of foundation models in AI applications. They are used throughout commercial AI products, but are r…
RENDER: Controlling Reader-Facing Evidence in LLM Memory Evaluation
Yuan Si, Simeng Han, Daming Li +1
Memory and RAG evaluations often treat the answering model's input as an implementation detail, even though systems may render the same history as a memory entry, summary, typed re…
Content Hidden Behind Execution: Analyzing Public Scratch Projects at Runtime
Yuan Si, Yufeng Lin, Daming Li +3
Public Scratch projects are reused in computing education as classroom examples, remix sources, open-exploration materials, and research data. Curation often begins with titles, th…
ScratchLens: Lens-Parametric Behavioral Equivalence for Scratch Programs
Yuan Si, Jialu Zhang
Two Scratch programs can be syntactically far apart-renamed variables, split scripts, extracted custom blocks, or reordered initialization-and still behave identically; a one-block…
EcoScratch: Cost-Effective Multimodal Repair for Scratch Using Execution Feedback
Yuan Si, Ming Wang, Daming Li +2
Scratch is the most popular programming environment for novices, with over 1.15 billion projects created worldwide. Unlike traditional languages, correctness in Scratch is defined…
ScratchEval : A Multimodal Evaluation Framework for LLMs in Block-Based Programming
Yuan Si, Simeng Han, Daming Li +2
LLMs have achieved strong performance on text-based programming tasks, yet they remain unreliable for block-based languages such as Scratch. Scratch programs exhibit deeply nested,…
Stitch: Step-by-step LLM Guided Tutoring for Scratch
Yuan Si, Kyle Qi, Daming Li +2
Block-based environments such as Scratch are increasingly popular in programming education. While block syntax reduces surface errors, semantic bugs remain common and challenging f…
ViScratch: Using Large Language Models and Gameplay Videos for Automated Feedback in Scratch
Yuan Si, Daming Li, Hanyuan Shi +1
Block-based programming environments such as Scratch are increasingly popular in programming education, in particular for young learners. While the use of blocks helps prevent synt…
ROVR-Open-Dataset: A Large-Scale Depth Dataset for Autonomous Driving
Xianda Guo, Ruijun Zhang, Yiqun Duan +9
Depth estimation is a fundamental component of spatial perception for autonomous driving and other unmanned systems operating in open urban environments. Existing depth datasets su…