{"id":126,"date":"2026-01-12T07:20:20","date_gmt":"2026-01-12T07:20:20","guid":{"rendered":"https:\/\/wordpress.cs.vt.edu\/rylai\/?page_id=126"},"modified":"2026-01-12T07:20:20","modified_gmt":"2026-01-12T07:20:20","slug":"guard","status":"publish","type":"page","link":"https:\/\/wordpress.cs.vt.edu\/rylai\/guard\/","title":{"rendered":"GUARD"},"content":{"rendered":"\n

A Hierarchical Deep Reinforcement Learning Chatbot for Cybergrooming Prevention.<\/strong><\/p>\n\n\n\n

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Cybergrooming poses an increasing risk to young internet users, necessitating proactive, AI-driven interventions. This work introduces an adaptive chatbot GUARD that enhances teenagers’ resilience against cyber-grooming through dynamic, human-like interactions tailored to individual vulnerability levels.<\/p>\n\n\n\n

The system integrates a large language model\u2014fine-tuned on a stage-tagged PJ dataset\u2014with hierarchical deep reinforcement learning to enable flexible transitions across six grooming stages via both reward and context-based signals. A master policy determines the current stage based on conversational cues, while six stage-specific sub-policies optimize responses by leveraging user sentiment and sub-goal achievement.<\/p>\n\n\n\n

Performance is evaluated via simulated interactions to ensure the quality of the chatbot prior to deployment. Ultimately, this research provides an AI-driven tool for enhancing online safety education and preventing cybergrooming.<\/p>\n\n\n\n

Publications<\/h2>\n\n\n\n

In Preparation<\/p>\n\n\n\n

Authors: Heajun An, Qi Zhang, Minqian Liu, Xinyi Zhang, Sangwook Lee, Dilruba Showkat, Prakriti Dumaru, Sang Won Lee, Lifu Hwang, Pamela Wisniewski, Jin-Hee Cho<\/p>\n\n\n\n

Presentations<\/h2>\n\n\n\n

ACM CAPWIC 2025 \u2013 Student Research Short Talk<\/p>\n\n\n\n

Presented “GUARD: A Hierarchical Deep Reinforcement Learning Chatbot for Cybergrooming Prevention” at ACM CAPWIC 2025, March 2025.<\/p>\n\n\n\n

Slides<\/a><\/p>\n\n\n\n

CCI Student Researcher Showcase 2025 \u2013 Poster Presentation<\/p>\n\n\n\n

Presented “GUARD: Grooming Understanding and Action via Reinforcement-based Defense” at the CCI Student Researcher Showcase, Virginia Tech, April 2025<\/p>\n\n\n\n

Poster<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

A Hierarchical Deep Reinforcement Learning Chatbot for Cybergrooming Prevention. Cybergrooming poses an increasing risk to young internet users, necessitating proactive, AI-driven interventions. This work introduces an adaptive chatbot GUARD that enhances teenagers’ resilience against cyber-grooming through dynamic, human-like interactions tailored to individual vulnerability levels. The system integrates a large language model\u2014fine-tuned on a stage-tagged PJ […]<\/p>\n","protected":false},"author":501,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-126","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/wordpress.cs.vt.edu\/rylai\/wp-json\/wp\/v2\/pages\/126","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wordpress.cs.vt.edu\/rylai\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/wordpress.cs.vt.edu\/rylai\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/wordpress.cs.vt.edu\/rylai\/wp-json\/wp\/v2\/users\/501"}],"replies":[{"embeddable":true,"href":"https:\/\/wordpress.cs.vt.edu\/rylai\/wp-json\/wp\/v2\/comments?post=126"}],"version-history":[{"count":1,"href":"https:\/\/wordpress.cs.vt.edu\/rylai\/wp-json\/wp\/v2\/pages\/126\/revisions"}],"predecessor-version":[{"id":129,"href":"https:\/\/wordpress.cs.vt.edu\/rylai\/wp-json\/wp\/v2\/pages\/126\/revisions\/129"}],"wp:attachment":[{"href":"https:\/\/wordpress.cs.vt.edu\/rylai\/wp-json\/wp\/v2\/media?parent=126"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}