VTechWorks
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.
Communities in VTechWorks
Select a community to browse its collections.
Recent Submissions
Topographic and depth-to-bedrock controls on non-perennial headwater streamflow
Morgan, John Cole (Virginia Tech, 2026-07-28)
Non-perennial headwater streams dominate river networks in terms of total flowing length and contribute substantially to downstream water conditions. The flowing extent of these streams varies over space and time, driven by several interacting controls that are themselves difficult to predict. Two of these major controls are topography and subsurface characteristics. The goal of this dissertation was to understand how topography and the distribution of subsurface storage, represented by depth-to-bedrock (DTB), interact to control patterns of non-perennial streamflow at the Hubbard Brook Experimental Forest in the White Mountains of New Hampshire. To do this, I conducted a field campaign to collect flowing-state observations for three non-perennial streams using a network of distributed flow presence and absence sensors. I paired these observations with a characterization of the depth-to-bedrock across one study watershed, combining passive seismic sensing with direct observations from ground surveys and soil pits. These datasets were integrated with a suite of topographic analyses and modeling methods, to examine how topography and depth-to-bedrock interact to explain wetting and drying patterns and flow persistence of a stream network. This dissertation had three research objectives: 1) to determine the order of wetting and drying in non-perennial stream networks during events, and if it can reveal catchment subsurface structure 2) to test whether characterization of depth-to-bedrock throughout a watershed explains flow persistence in a stream network, and 3) evaluating whether a process-based model with additional subsurface information can reproduce observed surface flow dynamics in space and time. Across these methods, both topography and subsurface properties explain processes that drive temporary flow in non-perennial streams. Non-perennial headwater streams do not activate in a fixed order of wetting and drying from event to event. There is no strong relationship between depth-to-bedrock and flow persistence, either locally or across hillslopes that drain to channel reaches. The process-based model was the most transferable approach, producing accurate predictions of discharge at the watershed outlet, but it could not resolve the finer-scale patterns of wetting and drying throughout the network. Explaining the controls of wetting and drying in non-perennial streams remains challenging, but this work validates past findings that topography-based frameworks are easy to implement and effective, and shows that, at least in these headwater networks, site-specific knowledge and thorough characterization of the subsurface does not improve the ability to predict these small, complex systems.
Opt-In Audibility for Bitcoin Transactions via Cryptographic Commitments in Taproot Change Outputs
Chandra, Pratyaksh (Virginia Tech, 2026-07-27)
Bitcoin transactions carry no native mechanism for linking an on-chain payment to its real- world commercial purpose. A self-custodying user who wishes to demonstrate that a specific transaction corresponds to a specific invoice — for tax reporting, corporate audit, or reg- ulatory compliance — has no standardised, cryptographically sound way to do so without revealing their full wallet history. Existing approaches either lack on-chain binding (BIP-70, manual record-keeping), impose visible overhead and privacy costs (OP_RETURN commit- ments), or operate on different platforms entirely (Zcash viewing keys, Lightning invoices).
This thesis presents an opt-in auditability protocol that embeds a cryptographic commit- ment to a structured invoice inside a standard Taproot change output using a pay-to-contract key tweak. The commitment adds zero bytes to the transaction, produces an output that is byte-for-byte indistinguishable from any other Pay-to-Taproot output, and requires no changes to Bitcoin's consensus rules. A new invoice format — the Signed Bitcoin Invoice (SBI) — organises payment metadata into a Merkle tree with per-field blinding nonces, en- abling field-level selective disclosure to auditors via inclusion proofs. An optional verifiable credential, embedded as a Merkle leaf, binds the merchant's identity to the payment address, providing pre-payment address authenticity verification.
Five security properties (commitment binding, commitment hiding, disclosure soundness, disclosure privacy, and non-repudiation) are formally argued via reductions to standard cryp- tographic assumptions. A game-theoretic analysis demonstrates that the invisibility of the mechanism is a prerequisite for the opt-in property to remain voluntary under regulatory pressure.
Tourist satisfaction and travel expenditures: A reference-dependent behavioral economics perspective
Jung, Hyojun; Nicolau, Juan Luis (Elsevier, 2026-07)
Motivated by limitations in priord research that assumes linear and symmetric satisfaction–spending relationships, this study applies a reference-dependent framework grounded in prospect theory to examine how tourist satisfaction measured relative to culturally and motivationally shaped reference points influences expenditure behavior in inbound tourism. Using a pseudo-panel of international tourists visiting South Korea and estimating a two-way fixed effects model, the results show that expenditure responds to deviations from reference points rather than to absolute satisfaction levels. Spending responses differ across gain and loss domains, with larger effects in the loss domain, and exhibit nonlinear dynamics. These findings suggest that reference-dependent evaluations systematically translate into observable tourist spending behavior, advancing behavioral perspectives in tourism expenditure research.
Efficiency and Equity in Screening for Participants in Representative Cybersecurity Studies
Chen, Po-Yu; Oh, Jinwoo; Hsing, Hsiang-Wen; Lau, Nathan; Beltz, Brandon; Wu, Peggy; Zhu, Quanyan (Springer, 2026-07-31)
Human factors research in cybersecurity confronts the practical challenge of how to recruit and screen participants with the skills necessary to perform
demanding, ecologically valid tasks. Credible results from hacking studies rely on
participants possessing sufficient technical skills to maneuver inside a representative network in a cyber range. Screening via self-reports can be unreliable, while
rigorous skills testing is resource intensive. This paper presents empirical research
investigating the effectiveness of cybersecurity certifications and cyber range skills
tests for screening domain-specific competence. The Guarding Against Malicious
Biased Threats (GAMBiT) project recruited participants with a two-stage screening process. The project screened 269 candidates for a final sample of 61 qualified
participants. We compared the capability between the Offensive Security Certified
Professional (OSCP) certification and a custom Capture-the-Flag (CTF) assessment (“Cedar Bunny”) at predicting actual performance in a two-day cyber range
experiment. Results indicate that OSCP holders scored significantly higher on the
skills test (p < 0.001) and progressed further in the hacking experiment (p =
0.002) than non-holders. Skills test scores correlated moderately and positively
with hacking progress (ρ = 0.344). Furthermore, hierarchical regression analysis
demonstrated that the skills test provided incremental predictive validity (ΔR2 =
5.2%) beyond certification alone. These findings suggest that while certifications
are efficient proxies and skills tests can be effective supplements for identifying
viable, albeit non-certified, participants. We propose a mixed screening approach
to balance recruitment efficiency and participant diversity.
Amonate, VA: Calhoun Pocket Park Conceptual Design
Gilboy, Elizabeth; Gleason, Harry; Ekberg, Caitlyn; Kakkadan, Sneha; Jain, Nidhi (Community Design Assistance Center, 2026-04-30)
Amonate Always has been working with Virginia Tech’s College of Architecture, Arts, and Design (AAD), including the Community Design Assistance Center (CDAC), to improve the quality of life in the historic coal camp since 2024. After an extensive inventory of the town in 2025, the original parsonage site of the Amonate Methodist Church was identified as a suitable place for a pocket park. Amonate Always recently purchased the site and, since the house no longer remains, the community would like to create a small pocket park on the site for community use.
Following an internal design charrette at CDAC in March of 2026, two preliminary design concepts were created and presented to the community on April 11, 2026. With feedback from this meeting, a final design concept was created and presented to Amonate Always and the community at the end of April 2026. This project is the first of many to be folded into a broader Community Revitalization Plan to be developed throughout 2026 for Amonate. The goal of the park, to be named Calhoun Park by local residents and those with ties to the camp, is to encourage healthy lifestyle habits like walking and play outside, protect pedestrians from street traffic, and create a community gathering space.