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Estimating and Project Management for the Construction of a Visitor Deck at City Farm SLO
Get PDFThis paper will outline the process of estimating and the project management of a visitor deck that was built at City Farm of San Luis Obispo, a local non-profit. The deck was built for the purpose of providing an area for visitors to observe the agricultural land where City Farm educates the community on ecology, nutrition, and sustainable farming. The construction of the deck was completed by three fourth-year Construction Management majors: Eric Cederstrom, Lane Lagomarsino, and Brett Jones. Each project team member was responsible for their own aspect of the project planning and all members collaborated throughout the entire building process. While the deck itself was the most significant project deliverable, this paper will focus on the project management deliverables completed by Eric Cederstrom, which include the estimation of the deck, the procurement of material, and acting as the main point of contact for communication between the two parties
Timber Buckling Restrained Brace
Get PDFThe timber buckling-restrained brace (TBRB) experiment at California Polytechnic State University, San Luis Obispo (Cal Poly), began in 2018 with the goal of finding whether timber may provide proper restraint against buckling of a steel brace. The TBRB was motivated by the limited lateral force resisting systems (LFRS) available for low-to-mid-rise, type V construction; this system would provide strength and ductility at a scale and level of cost appropriate to timber construction.
Early research consisted of uniaxial component testing, where researchers played with the balance between the core brace design and utilization of timber casings for buckling restraint, with minimal material use at the forefront. While iterating on the design, uniaxial component testing graduated to lateral braced-frame testing in Spring of 2021, eventually leading to the proof-of-concept design detailed in this report.
The TBRB research at Cal Poly culminated in June 2022 with the last braced-frame test resulting in a compression-to-tension capacity ratio of 1.06, with an average of 0.96 among the latest five tests. This research was presented at the Structural Engineers Association of California (SEAOC) Convention in 2022, accompanied with the publication of the following paper
Improving Relation Extraction from Unstructured Genealogical Texts Using Fine-Tuned Transformers
Get PDFThough exploring one’s family lineage through genealogical family trees can be insightful to developing one’s identity, this knowledge is typically held behind closed doors by private companies or require expensive technologies, such as DNA testing, to uncover. With the ever-booming explosion of data on the world wide web, many unstructured text documents, both old and new, are being discovered, written, and processed which contain rich genealogical information. With access to this immense amount of data, however, entails a costly process whereby people, typically volunteers, have to read large amounts of text to find relationships between people. This delays having genealogical information be open and accessible to all.
This thesis explores state-of-the-art methods for relation extraction across the genealogical and biomedical domains and bridges new and old research by proposing an updated three-tier system for parsing unstructured documents. This system makes use of recently developed and massively pretrained transformers and fine-tuning techniques to take advantage of these deep neural models’ inherent understanding of English syntax and semantics for classification.
With only a fraction of labeled data typically needed to train large models, fine-tuning a LUKE relation classification model with minimal added features can identify genealogical relationships with macro precision, recall, and F1 scores of 0.880, 0.867, and 0.871, respectively, in data sets with scarce (∼10%) positive relations. Further- more, with the advent of a modern coreference resolution system utilizing SpanBERT embeddings and a modern named entity parser, our end-to-end pipeline can extract and correctly classify relationships within unstructured documents with macro precision, recall, and F1 scores of 0.794, 0.616, and 0.676, respectively. This thesis also evaluates individual components of the system and discusses future improvements to be made
Model-Based Design of an Optimal Lqg Regulator for a Piezoelectric Actuated Smart Structure Using a High-Precision Laser Interferometry Measurement System
Get PDFSmart structure control systems commonly use piezoceramic sensors or accelerometers as vibration measurement devices. These measurement devices often produce noisy and/or low-precision signals, which makes it difficult to measure small-amplitude vibrations. Laser interferometry devices pose as an alternative high-precision position measurement method, capable of nanometer-scale resolution. The aim of this research is to utilize a model-based design approach to develop and implement a real-time Linear Quadratic Gaussian (LQG) regulator for a piezoelectric actuated smart structure using a high-precision laser interferometry measurement system to suppress the excitation of vibratory modes.
The analytical model of the smart structure is derived using the extended Hamilton Principle and Euler-Bernoulli beam theory, and the equations of motion for the system are constructed using the assumed-modes method. The analytical model is organized in state-space form, in which the effects of a low-pass filter and sampling of the digital control system are also accounted for. The analytical model is subsequently validated against a finite-element model in Abaqus, a lumped parameter model in Simscape Multibody, and experimental modal analysis using the physical system. A discrete-time proportional-derivative (PD) controller is designed in a heuristic fashion to serve as a baseline performance criterion for the LQG regulator. The Kalman Filter observer and Linear Quadratic Regulator (LQR) components of the LQG regulator are also derived from the state-space model.
It is found that the behavior of the analytical model closely matches that of the physical system, and the performance of the LQG regulator exceeds that of the PD controller. The LQG regulator demonstrated quality estimation of the state variables of the system and further constitutes an exceptional closed-loop control system for active vibration control and disturbance rejection of the smart structure
A Cradle-to-Gate Life Cycle Assessment of American Hops in the Craft Beer Supply Chain
Get PDFThe hop industry represents a culturally and economically significant industry in the United States due to the product’s significant role in the beer industry, but little is known about the environmental impacts associated with hop production. There exists a significant lack of specific research quantifying the emissions contribution of hop production, and the work that has been done lacks consensus in the scientific community. In an effort to overcome this, this study conducts a cradle-to-gate life cycle assessment (LCA) of aroma hop production broken into four phases, beginning with propagation of seedlings by tissue culture and ending with packaged T-90 hop pellets ready for shipment. Ultimately, the results of the study indicate that the production of 1 kg of HBC 394 T-90 aroma hop pellets results in a global warming potential (GWP) of 4.42 kgCO2e/kg and a eutrophication potential (EP) of 12.17 gNe/kg. The phase with the largest contribution to GWP in the production system is on farm cultivation. The single most significant GWP input in hop production is the kilning process (28.19%), which occurs during the harvest phase. Similarly, the phase with the largest contribution to EP in the production system is on farm cultivation, while the most significant EP input in hop production is electricity (63.07%), which occurs during all four phases of production. While the environmental impacts of hop production are on the higher side when compared to the same amount of other agricultural products, impacts are relatively low when compared to the impacts per serving of other crops -- 1 kg of hop pellets can produce well over 100 servings of a relatively highly hopped beer. The results of this study offer baseline data with respect to the GWP and EP of hop production, but ultimately, further research is recommended to verify the results of this study and identify specific opportunities for reduction of environmental impacts
Addition of an Internship Prep Course to the CM Curriculum
Get PDFThe Cal Poly Construction Management program does an amazing job giving students opportunities to receive summer internships. Just about every student in the CM program will have some form of summer internship during their time at Cal Poly. All CM classes are designed to prepare students for internships. That being said, there is no specific class within the CM curriculum that is 100% Internship focused. Allowing students an opportunity to take a course that would focus on preparing them for their summer internships, students will be more confident and better equipped to take on the tasks of an intern at a construction company. This course is designed to teach skills and concepts related to internships within the construction industry. These skills and concepts will teach students how to get the most out of their internships and navigate potential scenarios they might face. This paper will analyze student interest in taking this course. It will also decide some of the topics that will be taught. A survey was conducted in order to receive feedback from Construction Management students about interest in this course. The results of this survey showed that this course does not have enough student interest to implement into the curriculum
BARRIERS AND MOTIVATIONS TO RESIDENTIAL PRO-ENVIRONMENTAL ACTIONS IN SAN LUIS OBISPO
Get PDFCarbon neutrality has become an important focus for many municipalities, with the inclusion of mitigation measures targeted at the residential sector becoming increasingly prominent for the implementation of climate action plans (CAPs). However, many analyses fall short in identifying the barriers and motivations faced by residents to adopting pro-environmental actions in their daily lives, focusing instead on the available actions themselves. This research aims to identify both the barriers and motivations to adopting pro-environmental behaviors and assess their relationship(s) to key demographic variables, along with climate change perceptions. Using the city of San Luis Obispo (SLO) as a case study, this project used an online residential engagement survey administered to the general public through several mechanisms, including in-person and online platforms. The study reveals that the greatest barrier to SLO residents’ implementing pro-environmental behaviors is affordability, with accessibility coming in second, and the most common motivation is climate change concerns. The results further indicate that ranking climate change concerns higher on a scale of 1 to 10 significantly increase the chance of selecting climate change as a primary motivation for adopting pro-environmental behavior. Additionally, we found significant variability among those of differing socioeconomic status (SES) in selection of barriers. These results suggest that SLO should address the most pertinent identified barriers through structural solutions, with an emphasis on their varied distribution across demographic groups, while continuing to encourage existing motivations. Such efforts would help SLO move toward necessary greenhouse gas emission reductions to achieve carbon neutrality by 2035
Extreme Tail Ratios and Overrepresentation among Subpopulations with Normal Distributions
Get PDFGiven several different populations, the relative proportions of each in the high (or low) end of the distribution of a given characteristic are often more important than the overall average values or standard deviations. In the case of two different normally-distributed random variables, as is shown here, one of the (right) tail ratios will not only eventually be greater than 1 from some point on, but will even become infinitely large. More generally, in every finite mixture of different normal distributions, there will always be exactly one of those distributions that is not only overrepresented in the right tail of the mixture but even completely overwhelms all other subpopulations in the rightmost tails. This property (and the analogous result for the left tails), although not unique to normal distributions, is not shared by other common continuous centrally symmetric unimodal distributions, such as Laplace, nor even by other bell-shaped distributions, such as Cauchy (Lorentz) distributions