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STOCHASTIC ANALYSIS WITH OPERATIONAL CALCULUS IN RELIABILITY
Full text linkOur dissertation models several reliability systems subject to occasional random shocks of random magnitudes W1,W2,..occurring at times tau0, tau2,..In Model 1, the underlying system becomes inoperational if it wears out due to aging specified by a monotone increasing continuous function Delta identifying system\u27s wear at any time t\u3e=0 . The system is deemed inoperational if delta crosses a sustainability threshold at some moment T=(delta )^-1(D). The precise time T is difficult to identify making the realistic failure time randomly delayed and thus identified at some opportune observation epoch. The system can also fail due to damages by external shocks, some of which are harmless and some other - critical categorized through their magnitudes relative to a specified threshold H1 . The kth shock is harmless if Wk\u3c =H1and critical if Wk \u3eH1 . It takes a total of N critical shocks to knock the system down. In a nutshell, the system fails if it is worn out assessed at some random observation point or if it is hit by a total of N critical shocks whichever of the two events comes first.
In Model 2, we introduce four types of shocks that land at the system: again harmless and critical (as in Model 1) and additionally extreme and delta-shocks. The kth shock is extreme if Wk\u3eH2 where H1
In Model 3, we exclude harmless shocks from those we deemed delta . Namely, a shock can only be delta when it is critical or extreme and when the previous critical shock is not extreme and lags within an interval of delta-length. In this model we had to restructure the stream of shocks by dropping those defined as harmless and study the system on a conditional probability space. In all three models we obtain closed-form joint distributions of the time-to-failure shock count upon failure, delta-shock count, and cumulative damage to the system on failure, among other less significant characteristics. In particular, the reliability function (a quintessential merit in reliability modeling) directly followed from the marginal distribution of the failure time. We treated the systems as generalized random walk processes and use embellished variants of discrete operational calculus. We demonstrate analytical tractability of our formulas through various examples and special cases. The accuracy has also been validated through Monte Carlo simulation
Event Horizon Award Event
No full textFor its 40th Anniversary, the Evans Library held the contest Event Horizon sponsored by the Astronaut Memorial Foundation, asking students to use library resources to describe the next 40 years of space exploration. Hear Dean Jason Martin, President John Nicklow, and retired astronaut Bob Cabana. Hear from the contest winner
The Impact of Sibling Sexual Abuse on Parenting Stress
Full text linkSibling sexual abuse is the most common yet least reported, treated, and studied manifestation of child sexual abuse (Bertele & Talmon, 2023; Caffaro & Conn-Caffaro, 2005; Krienert & Walsh, 2011; O’Brien, 1991). It is a particularly challenging form of intrafamilial sexual abuse for parents and caregivers because their children are both the victim and the perpetrator of the abuse. They struggle to balance the needs of both children (Duane et al., 2002; Tener et al., 2020) and may experience heightened stress and associated psychological difficulties. Parenting stress is linked to child and adolescent posttraumatic stress and internalizing and externalizing problem behaviors (Crusto et al., 2010; Whitson et al., 2015; Whitson & Kaufman, 2017); however, there is no body of research investigating the impact of sibling sexual abuse on parenting stress. This study aimed to examine how sibling sexual abuse relates to parenting stress. It also sought to determine the relationship between sibling sexual abuse and child and adolescent posttraumatic stress and internalizing and externalizing problem behaviors. The study found a significant positive relationship between sibling sexual abuse and parenting stress for caregivers of adolescents. Caregivers of adolescents who experienced sibling sexual abuse also reported significantly greater stress pertaining to their concerns about their adolescent\u27s emotions and behaviors. Additionally, sibling sexual abuse was found to be significantly negatively correlated with internalizing symptoms for children but not for adolescents. These findings have implications for the treatment of sibling sexual abuse and provide support for a family treatment model
Oral History Interview with Richard Enstice, 2025
No full textThis interview with Richard Enstice by Gordon Patterson, dated September 25, 2025, covers Enstice\u27s decades-long career at Florida Tech, beginning with his arrival in 1966. Enstice discusses his academic path from a bachelor\u27s degree in electrical engineering (one of the first to graduate with ABET accreditation) to a master\u27s degree, and his subsequent decision not to pursue a Ph.D. due to the lack of financial support for full-time Ph.D. students with a family.
A significant portion of the interview is dedicated to his impressions of key figures and programs: Dr. Walter Nunn, his major advisor and head of the electrical engineering program, is described as technically excellent, dedicated, and eccentric, often putting his own money into the labs and focusing intently on his work to the exclusion of other aspects of life. Dr. David Woodbridge of the science education program is characterized as a con artist with okay ideas but a dubious reputation for his off-campus program ventures. The Science Education Program was a good, exciting program that Enstice enjoyed and taught in every term. Enstice compares five university presidents: Jerry Keuper, John Miller, Lynn Weaver, Anthony Catanese (Tony), and Dwayne McCay. He views Lynn Weaver as having moved the university forward the most, particularly with new buildings. He had problems with McCay, who he felt wanted instant results and discouraged faculty from teaching in favor of 100% administration. Tony Catanese was a front man and showman who sought fame and glory (e.g., wanting to build a football team) and largely avoided faculty problems. Jerry Keuper is noted for not having people to ground him, leading to mistakes like hiring Woodbridge.
Enstice details his diverse roles, including his time as Provost and Vice President of Academic Affairs (his most enjoyable position). He also discusses his role as a problem solver for Harry Weber (including a cultural challenge with Indian graduate students), and his accidental involvement in off-campus programs. He points to the development of the Link Building and the strategic plan for reaccreditation as key forward moments
Oral History interview with Deborah Heystek, Alumnus on the Botanical Garden
No full textIn this interview conducted by Gordon Patterson on August 5, 2025, Florida Tech alumna Deborah Heystek recounts her experiences as a student in the 1970s and shares her deep connection to the university\u27s botanical garden, then known as the jungle. Ms. Heystek arrived at FIT in 1975, initially as a marine biology major before gravitating toward ecology. She describes a small, self-contained campus where student life revolved around the jungle, which served as a backyard, a social hub, and a place for recreation and mental respite from challenging coursework
Mental Health and Willingness to Seek Mental Health Aid in Aviation
No full textNo relationship was found between aviation student mental health status and willingness to seek mental health aid; there was no difference in willingness to seek help between pilots and non-pilots
Experimental and Theoretical Fracture Analysis of Additively Manufactured Orthotropic V-Notches
Full text linkThis study presents a comprehensive investigation into the fracture behavior of additively manufactured orthotropic V-notched components made of Acrylonitrile Butadiene Styrene (ABS) material. The research integrates both theoretical and finite element approaches to evaluate stress intensity factors (SIFs) in Modes-I and II, which are fundamental in characterizing stress field distributions around notches under applied loading conditions. Unlike isotropic materials, where stress fields depend only on geometry of the component, the anisotropic nature of 3D-printed ABS introduces a dependency on material properties that necessitate different approaches to include anisotropy of the material.
Tensile specimens are 3D-printed with specific material orientations to find material properties. Tensile and shear tests are conducted using a Universal Testing Machine (UTM) equipped with Digital Image Correlation (DIC) for precise stress and strain measurement. The determined material properties were then used in calculating the eigenvalues, derived from a characteristic equation dependent on material properties, notch opening angles, and geometric parameters. Once the eigenvalues are determined, SIFs for both mode-I and mode-II are determined and integrated into stress field equations to predict fracture behavior around the notch tips. These theoretical predictions of stress fields were validated through Finite Element Analysis (FEA) simulations, which model the stress distributions around the notch tip with varying print orientations.
Fracture specimen are 3D-printed using ABS and were tested on a tensile tester to determine the fracture load. The obtained fracture load is used to calculate SIFs at the onset of fracture through normalized FE simulations. This study highlights the importance of material orientation in influencing fracture modes, with Mode I and Mode II dominance shifting based on material orientation. The findings of this research contribute valuable insights into the fracture mechanics of 3D-printed materials that usually exhibit orthotropic behavior due to print orientation, offering a deeper understanding of stress distributions in notched structures. The results emphasize the crucial role of material properties in understanding fracture behavior in an anisotropic environment, making this study highly relevant to aerospace, automotive, and structural engineering applications where customized 3D-printed components are increasingly utilized
Project Vulcan
Full text linkProject Vulcan is a proof-of-concept metal 3Dprinted clustered chamber aerospike with integrated Liquid-Injected Thrust Vector Control (LITVC), improving control and efficiency across altitudes. In partnership with Vaya Space, our design aligns with the Dauntless launch vehicle. The project focuses on the design, construction, and validation of the aerospike via additive manufacturing, static fire testing, and altitude simulation
An integrative approach to studying exoplanet environments
Full text linkThe aim of this project is to evaluate volcanic influences on biogeochemistry by implementing a continuous and time integrated biogeochemical model to simulate earth-like exoplanets
Habitable Zones Surrounding Active Galactic Nuclei
Full text linkThe habitable zone (HZ) refers to an area in a galaxy, around a supermassive black hole that can host life. Each galaxy is considered “active”, meaning it emits winds at extremely high velocities. We consider the winds to be driven by energy output from the supermassive black hole