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VTechWorks provides global access to Virginia Tech scholarship, including journal articles, books, theses, dissertations, conference papers, slide presentations, technical reports, working papers, administrative documents, videos, images, and more by faculty, students, and staff. Faculty can deposit items to VTechWorks from Elements, including journal articles covered by the University open access policy. Email vtechworks@vt.edu for help.
Open Access Policy
Virginia Tech's open access policy enables researchers to deposit the accepted version of scholarly articles with no embargo.
Theses and Dissertations
Virginia Tech was first in the world to require ETDs in 1997, and continues to add scans of older theses and dissertations.
Open Textbooks
More than 50 freely available and openly licensed textbooks are among our most downloaded items.
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Recent Submissions
Social Robots for Human Companionship: Stigma Perceptions, Social Orientation, and Design Preferences
Ahmed, Iqbal Uddin (Virginia Tech, 2026-03-06)
Advances in artificial intelligence (AI) have transformed the capabilities of social robots, enabling them to participate in interactions that resemble human social exchange. Through adaptive learning and personalized engagement, these systems can provide counsel, emotional support, and companionship across a range of social contexts. Individuals perceive the advantages of interacting with a social robot (vs. human) such as being perceived as nonjudgmental, reduced risk of social rejection, accessible, and emotionally responsive interactions. As social robots become increasingly capable of simulating humanlike social presence, these developments raise important questions about the psychological processes that underlie how individuals perceive, evaluate, and adopt social robot as companions.
Researchers in marketing, robotics, and computer science have largely focused their attention on facilitating factors that lead to social robot acceptance. Such findings may lead designers to adopt a "one-size-fits-all" perspective. However, far less is known about individual differences in social robot preferences. In addition, the literature is sparse on how social robot designs may influence stigma perceptions. In particular, there is a gap in our understanding of how social robots with anthropomorphic designs may drive inferences of humanlike capabilities, elicit stigma, and the psychological processes by which stigma shapes resistance to social robot companionship.
This dissertation examines how social robot design activates psychological mechanisms that influence the adoption of AI-driven social robots for companionship. Essay 1 (Chapter 2) investigates how anthropomorphic design features shape perceptions of a social robot's cognitive, affective, and social capabilities and how these inferences mediate perceived stigma (in parallel). We then investigate a psychological process in which perceived stigma, anticipated stigma, and self-stigma serially mediate adoption intentions for social robots as companions.
Essays 2 and 3 address individual differences in social relationship orientations that may signal differential benefits from AI companionship. Drawing on literature in social competence, exclusion, and solitude, Essay 2 (Chapters 3 and 4) develops a scaling methodology that classifies individuals as socially included (I), socially excluded (D), or social excluders (R).
Using a multi-stage process, we create and validate a 42-item instrument that distinguishes these social relational profiles. Finally in Essay 3 (Chapter 5) we explore how design preferences for social robots (physical features, anthropomorphic qualities, interactional capabilities, and preferred relational roles) vary by these social relationship profiles.
Together, these essays provide a comprehensive framework for understanding how stigma, individual differences, and design considerations may interact and influence the adoption of social robot companions. The dissertation concludes with theoretical, managerial, and policy implications for designing and responsibly deploying AI technologies that support human social needs and address the growing societal challenge of companionship deficits and loneliness.
Scalable Systems for Machine Learning
Khan, Ahmad Faraz (Virginia Tech, 2026-03-06)
Federated Learning (FL) enables collaborative model training without centralized data collection, thereby preserving data privacy and reducing data transfer costs. However, deploying FL in resource-constrained distributed environments like Edge and IoT applications introduces significant challenges related to cost, scalability, and efficiency. Traditional cloud-based FL aggregator solutions are resource-inefficient and expensive when applied at the Edge, leading to low scalability and high latency. Additionally, client-side resource heterogeneity results in issues such as stragglers, dropouts, and performance variations, complicating effective client participation.
This thesis explores these challenges and presents methodologies and frameworks that enhance the efficiency and scalability of FL systems in resource-constrained environments. First, an adaptive FL aggregator is presented, which is designed specifically for Edge environments, enabling users to manage the trade-off between cost and efficiency. This adaptive aggregator addresses the inefficiencies of cloud-based solutions by improving scalability and reducing latency. Second, we develop FLOAT, a framework that enhances FL client resource awareness by dynamically optimizing resource utilization to meet training deadlines and mitigating stragglers and dropouts through various optimization techniques. FLOAT employs multi-objective Reinforcement Learning with Human Feedback (RLHF) to automate the selection and configuration of these techniques, tailoring them to individual client resource conditions.
Third, we design IP-FL, which treats incentivization and personalization in FL as interrelated challenges and solves them with an incentive mechanism that fosters personalized learning.
IP-FL allows clients to indicate their cluster membership preferences based on data distribution and incentive-driven feedback without involving the aggregator to preserve privacy. This approach enhances the personalized model appeal for self-aware clients with high-quality data, leading to their active and consistent participation.
Lastly, FLStore is proposed as a serverless framework for efficient FL non-training workloads and storage. FLStore unifies the data and compute planes on a serverless cache, enabling locality-aware execution via tailored caching policies to reduce latency and costs compared to cloud-based in-memory and object stores.
FLStore integrates seamlessly with existing FL frameworks with minimal modifications, while also being fault-tolerant and highly scalable.
Our work aims to contribute toward the development of efficient and scalable machine learning systems suitable for widespread deployment in Edge and IoT applications, addressing the critical challenges of cost, scalability, and efficiency in resource-constrained distributed learning environments.
Introduction to Adulthood and Aging
Khan, Maham (2026-03-06)
Introduction to Adulthood and Aging (2026) is a research-based, 358-page Open Educational Resource (OER) adapted with original material added for use in Virginia Tech’s Human Development course, HD 2004: Adulthood and Aging. This text aims to spark reader ideas to address the significant global challenges and opportunities related to aging worldwide, exploring development, loss, resilience, and change and challenging common assumptions about aging. More than just a textbook, this resource is intended to spark reflection, empathy, and connection. The text is a foundation of knowledge and compassion that can be applied in both academic and personal settings, assisting readers to engage with the topic in practical and meaningful ways.
Developed in response to the increasing cost of textbooks, with the goal of reducing the financial burden on students and families, Introduction to Adulthood and Aging adapts and expands the openly-licensed works of other authors. It was adapted with original content added from existing openly-licensed texts, developed as a course reader in Canvas, and has been converted into MSWord and PDF. It is shared broadly in an effort to increase access to the content. While it is freely available under a Creative Commons Attribution NonCommercial ShareAlike (CC BY NC-SA) 4.0 license, the value of the content remains high, grounded in research, empathy, and a commitment to accessible education.
Instructors reviewing or adopting this book for a course, please help us understand your use by filling out this form: https://bit.ly/interest_introductiontoadulthoodandaging
Table of Contents
Unit 1: Introductions to Lifespan Development, Gerontology Theories, and Research Methods
1: Introduction to Lifespan Development and Adulthood
2: Lifespan Development Theories
3: Research in Lifespan Development
Unit 2: Early Adulthood
4: Emerging Adulthood and Early Adulthood
5: Cognitive Development in Early Adulthood
6: Psychosocial Development in Emerging and Early Adulthood
7: Relationships and Intimacy in Early Adulthood
Unit 3: Middle Adulthood
8: Middle Adulthood
9: Cognition, Social & Emotional Development Among Middle Adulthood
10: Relationships in Middle Adulthood
Unit 4: Older Adulthood
11: Older Adulthood
12: Physical and Sensory Changes in Older Adulthood
13: Brain Functioning and Sleep in Older Adulthood
14: End-of-Life Decision Making and Care
15: Death, Mourning, and Bereavement About the Editor
Maham Khan, Ph.D. is a researcher and educator whose work focuses on cognitive aging, resilience, and the diverse factors that shape well-being in later life. She completed her Ph.D. in Human Development and Family Science (Adulthood & Aging) at Virginia Tech in 2025. Her research examined cognitive superaging and lifestyle behaviors that contribute to healthier cognitive trajectories among older adults. She has also worked on chronic conditions and cognition, and functional limitations among older adults and unmet needs for caregiving. Her work draws on large-scale longitudinal datasets and advanced latent-variable modeling to better understand the behavioral, biological, and social determinants of optimal aging. During her doctoral training, Maham taught Adulthood and Aging at Virginia Tech as Instructor of Record and contributed to cognitive wellness initiatives for older adults through her work at the Engagement Center for Creative Aging. She has also served as a Visiting Lecturer in Pakistan, teaching healthcare management and primary healthcare, reflecting her commitment to interdisciplinary education and global perspectives on aging. Her publications span cognitive health, unmet needs, mobility limitations, and biomarker-informed aging research. She is now pursuing postdoctoral research training at Northwestern University, where she is expanding her work on cognitive resilience, aging trajectories, and translational approaches to cognitive health. Project support
This project was made possible in part through financial support from the University Libraries’ Open Education Initiative and Virginia Tech’s Department of Human Development and Family Science. Suggested citation
Khan, Maham. (2026) Introduction to Adulthood and Aging. Virginia Tech Libraries. https://hdl.handle.net/10919/142129 CC BY NC-SA 4.0 Accessibility
Virginia Tech is committed to making its publications accessible in accordance with the Americans with Disabilities Act of 1990. The text, images, and links in the PDF and MSWord versions of this text are tagged structurally and include alternative text, which allows for machine readability.
Unit 1: Introductions to Lifespan Development, Gerontology Theories, and Research Methods
1: Introduction to Lifespan Development and Adulthood
2: Lifespan Development Theories
3: Research in Lifespan Development
Unit 2: Early Adulthood
4: Emerging Adulthood and Early Adulthood
5: Cognitive Development in Early Adulthood
6: Psychosocial Development in Emerging and Early Adulthood
7: Relationships and Intimacy in Early Adulthood
Unit 3: Middle Adulthood
8: Middle Adulthood
9: Cognition, Social & Emotional Development Among Middle Adulthood
10: Relationships in Middle Adulthood
Unit 4: Older Adulthood
11: Older Adulthood
12: Physical and Sensory Changes in Older Adulthood
13: Brain Functioning and Sleep in Older Adulthood
14: End-of-Life Decision Making and Care
15: Death, Mourning, and Bereavement About the Editor
Maham Khan, Ph.D. is a researcher and educator whose work focuses on cognitive aging, resilience, and the diverse factors that shape well-being in later life. She completed her Ph.D. in Human Development and Family Science (Adulthood & Aging) at Virginia Tech in 2025. Her research examined cognitive superaging and lifestyle behaviors that contribute to healthier cognitive trajectories among older adults. She has also worked on chronic conditions and cognition, and functional limitations among older adults and unmet needs for caregiving. Her work draws on large-scale longitudinal datasets and advanced latent-variable modeling to better understand the behavioral, biological, and social determinants of optimal aging. During her doctoral training, Maham taught Adulthood and Aging at Virginia Tech as Instructor of Record and contributed to cognitive wellness initiatives for older adults through her work at the Engagement Center for Creative Aging. She has also served as a Visiting Lecturer in Pakistan, teaching healthcare management and primary healthcare, reflecting her commitment to interdisciplinary education and global perspectives on aging. Her publications span cognitive health, unmet needs, mobility limitations, and biomarker-informed aging research. She is now pursuing postdoctoral research training at Northwestern University, where she is expanding her work on cognitive resilience, aging trajectories, and translational approaches to cognitive health. Project support
This project was made possible in part through financial support from the University Libraries’ Open Education Initiative and Virginia Tech’s Department of Human Development and Family Science. Suggested citation
Khan, Maham. (2026) Introduction to Adulthood and Aging. Virginia Tech Libraries. https://hdl.handle.net/10919/142129 CC BY NC-SA 4.0 Accessibility
Virginia Tech is committed to making its publications accessible in accordance with the Americans with Disabilities Act of 1990. The text, images, and links in the PDF and MSWord versions of this text are tagged structurally and include alternative text, which allows for machine readability.
University Curriculum Committee for General Education: December 3, 2025
(Virginia Tech, 2025-12-03)
University Curriculum Committee for General Education: May 7, 2025
(Virginia Tech, 2025-05-07)