100039 research outputs found
Sort by
Blind Construction of a Party Check Matrix for Arbitrary Linear Block Codes
Get PDFCommunication systems are systems in which a transmitter sends data across a channel to a receiver. In any modern communication system, Forward Error Correction (FEC) is used to detect and correct errors that occur during transmission. As communication systems have developed over the years, many FEC algorithms have been proposed. Each FEC algorithm has parameters that can be selected based on the needs of the communication system. Typically, the transmitter and receiver are both aware of the FEC parameters, but in some cases the receiver may not know how the transmitter encoded its message. In this case, the receiver must blindly determine the FEC parameters.
This thesis offers a method to blindly recognize an important parameter of the FEC code, called a parity check matrix. The parity check matrix helps the receiver to decode the messages sent by the transmitter. The method described in this paper takes a noisy transmission and determines a parity check matrix without any prior knowledge of the FEC code. While the method outlined in this thesis does not work for every type of FEC code, it works for a category of FEC commonly used in modern communication systems called linear block codes
Contrastive Representation Learning for Highly Imbalanced Multivariate Time Series With Extreme Instance Strategy
Get PDFTime series data refers to a sequence of data points collected or recorded at regular time intervals. In many fields including space weather, healthcare, and finance, predicting events from such data is crucial because these predictions can help protect infrastructures, improve healthcare outcomes, and forecast financial trends. However, one challenge in working with time series data is the presence of rare events, which are often underrepresented in the data. This imbalance makes it difficult for traditional prediction methods to provide accurate results, as they tend to focus more on the more frequent events and overlook the rare ones. To tackle this challenge, this research introduces a new approach using contrastive representation learning. This method improves the ability to predict rare events by learning more effective representations of the data. Specifically, contrastive learning helps group similar data points together in a way that emphasizes the important differences between classes, such as rare and common events. By learning to focus on these distinctions, the approach provides better predictions, even in situations where the data is imbalanced. In this work, the proposed method first extracts key features from time series data, then creates meaningful representations that help distinguish between the different types of events. These representations are refined by training a model to recognize patterns over time, capturing the dynamic nature of the data. A final classification step uses these learned features to make accurate predictions. The method was tested on several datasets, including one focused on predicting solar flare events, which is an important task in space weather forecasting. The results show that the approach effectively addresses the challenges of class imbalance, providing more reliable predictions that can be applied to a wide range of time series prediction tasks. By offering a powerful solution to the problem of imbalanced time series data, this research has the potential to improve predictions in areas where rare but impactful events can have serious consequences, ultimately benefiting society by enhancing our ability to forecast and respond to critical events in real time
Maximizing Dryland Seed-Based Restoration Success Via Retrospective Analyses of Species-Use Patterns and Field Testing of Seed Mix Composition
Get PDFDue to harsh and variable environmental conditions, successful plant establishment in dryland ecosystems – areas with scarce precipitation – is a major challenge for restoration. One of the most important decisions influencing restoration outcomes is choosing which species to plant (i.e., species selection). Here I explored two opportunities to improve restoration success related to species selection. First, I examined recent restoration projects across Utah, USA to understand species selection patterns by site conditions (e.g., precipitation, elevation) and seed costs, and to identify tools for matching species to sites. Second, I tested how commonly used non-native species – those not originally from the region, but sometimes used for their quick establishment and high seed production – affect native species abundance and community diversity, and whether adding more natives to a mix (increasing richness) and/or applying more seeds (increasing seeding rate) improved a) seed mix performance (e.g., weed suppression, grass establishment, diversity) in native-only mixes or b) native abundance and community diversity when co-seeded with non-natives.
From the first study, I found that species choices generally followed planting guidelines (e.g., appropriate elevation) and seed supplier recommendations (e.g., precipitation requirements) and that more expensive seeds were selected less often – even when ecologically valuable. Species selection aligned with the Resistance and Resilience (R&R) framework, which classifies sites by their potential to resist invasion and recover from stress. A species\u27 suitability for a site was prioritized over its origin (native vs. non-native), and seed mix composition varied according to the R&R framework. In the field experiment, high-performing non-native grasses reduced native species (but not overall diversity), though increasing native richness helped offset this. Native-only mixes suppressed weeds as effectively as mixes with both natives and non-natives but yielded lower overall grass abundance. However, increasing seeding rates and richness in native-only mixes helped compensate for this difference.
These findings highlight opportunities to a) prioritize research and development for ecologically-valuable species to reduce costs, b) test R&R as a tool for seed mix design, c) co-seed natives and non-natives while balancing multiple goals, and d) reduce reliance on non-natives by increasing the use of native plant species
Approaches to Improve \u3ci\u3eIn Vitro\u3c/i\u3e Oocyte Maturation and Somatic Cell Nuclear Transfer Embryo Developmental Potential
No full textSomatic cell nuclear transfer (SCNT), a technique used in agricultural and biomedical fields for cloning livestock and creating animal models of diseases, is very inefficient. Cloned offspring that survive are usually only produced around 1% of the time, but our previous study showed that adding certain immune-system related proteins (FGF2, LIF, and IGF1, known as FLI) during cow egg (oocyte) maturation in a laboratory improved embryo development and cloning efficiency. Additionally, obtaining sheep eggs through a minimally invasive technique called laparoscopic ovum pick-up (LOPU) showed a positive effect on embryo development following in vitro fertilization (IVF). Therefore, we focused on finding the reasons behind improved SCNT efficiency after FLI supplementation as well as the effect of LOPU on sheep cloning.
Our first study compared cow oocytes that were treated with FLI during their growth to those that were not. We found that FLI-treated oocytes mature better in two important areas: their DNA (nuclear) and their organelles (cytoplasmic). The treated oocytes went through the first meiotic cell division more smoothly, with fewer problems in the structure that is created to separate DNA (the meiotic spindle). The treated oocytes also had better-organized mitochondria (the cell\u27s energy powerhouses) and cortical granules (the cell\u27s defense mechanism against multiple sperm fertilizing the egg). This suggests that adding FLI helps the oocytes develop more fully and become better candidates for successful cloning or other assisted reproduction techniques.
Our second study aimed to understand how adding FLI during oocyte growth in an incubator affects cloned cattle embryos. We analyzed three key areas that are often disrupted during cloning: how the DNA and RNA are marked or modified (epigenetic changes), how the cells grow and divide (morphokinetics), and how fats are stored in the embryos. Cloned embryos derived from FLI-treated oocytes had more consistent DNA and RNA modification profiles, increased morphokinetic activity, and enhanced fat accumulation compared to cloned embryos that did not come from oocytes treated with FLI. This suggests that FLI improves embryo development and growth, making the cloning process more successful.
In our last study, we looked at how collecting sheep oocytes using a technique called LOPU affects the development of cloned embryos. LOPU-collected oocytes matured better than those from a slaughterhouse, even outside the typical sheep breeding season (short days). During the breeding season, cloned embryos from LOPU oocytes were better at reaching a key development stage (the blastocyst), though the number of cells in the embryos was similar to those made from slaughterhouse oocytes. Sheep that received cloned embryos produced from LOPU oocytes had higher pregnancy rates and fewer losses during pregnancy. Most importantly, using LOPU oocytes increased the success of SCNT cloning from 2% to about 10%, which is a big improvement. This suggests that sheep oocytes collected by LOPU are better at developing into healthy embryos, making the cloning process more successful.
In simple terms, this research has helped us understand the different factors that improve the success of cloning in both cows and sheep, making the process more efficient and potentially guiding future research in other species
A Laboratory Study of Local Scour and Driftwood Effects at a Type A Piano Key Weir
Get PDFPiano key weirs are a unique weir designed to increase the amount of flow that passes over it via its zig-zag shape (similar to the rectangular shape of keys of a piano). With its relatively small footprint, they are becoming more popular to upgrade existing water management projects and are also being used in new construction works. However, there is little information available regarding how these weirs handle sediment and driftwood. Additional information will help researchers and designers to understand the challenges of upstream sediment buildup, driftwood accumulation, and the effects of floods on downstream scour with viable protection measures. Therefore, experiments were conducted in the laboratory to analyze these behaviors. This data was complimented by information from computer models. These results showed that these weirs have the ability to transport sediment from upstream to downstream reach without human removal. Similarly, driftwood accumulation against the weir, which can sometimes clog waterways, in fact enhanced the sediment removal. Results from experiments were used to test the physics-based prediction model which was validated, facilitating estimation of scour as a function of time. This model hence unfolds critical results for engineers and practitioners in designing the structures. In addition, studies performed using protection measures showed effective reduction of scour depth with concrete slabs and with large rock that helped reduce structural vulnerability from toe scour
Understanding how Adult Survivors of Childhood Cancer Narrate Their Lived Experience: Memorable Messages of Childhood Cancer Survivors
No full textChildhood cancer affects thousands of children and families in the United States, leaving lasting emotional, physical, and psychological impacts on survivors. This study includes interviews with 13 survivors of childhood cancer to explore messages that stuck with them over time from their cancer journey. Researchers identified five types of messages that were prominent: (a) helpful support, (b) battle metaphor, (c) hurtful, (d) diagnosis and (e) limitation. These messages influenced survivors\u27 self-perception, relationships, attitudes towards cancer, views on mortality, sense of responsibility, need for control and commitment to helping others. The findings highlight important ways to improve communication in cancer care, including how diagnoses are delivered, how resilience is fostered, the trust or distrust of medical professionals, communication between parents and children, and the use of battle metaphors in communication about cancer
Color Expressions in Euripides’ \u3ci\u3eIon\u3c/i\u3e
Get PDFThis analysis explores color expressions in the play Ion by the ancient Greek playwright Euripides. Because the ancient Greeks experienced color differently, I examined words used in the play, including light, dark, fire, green, water, blood, and gold. These expressions imply different themes and concepts that Euripides uses to portray the duality between his two main characters, Ion and Creusa. This thesis showed how the mother-son pair acts as a foil for the different aspects of color found throughout the play that reflect ancient Greek culture
Optimizing Accessibility Training by Prioritizing Cognitive Needs of Students with Disabilities
Get PDFDespite the significant enrollment of students with disabilities in higher education, research and practice rarely center the voices and leadership of these students, particularly in accessibility training efforts. This paper addresses this gap by presenting an autoethnographic study of a digital accessibility training initiative co-led by a student with multiple disabilities. Using a process that combines participatory research and first-person narrative, this study outlines the development and implementation of faculty training on accessibility that centers the experiences of a student with cognitive disabilities. We propose a new framework for understanding dynamic disability, a concept that recognizes the complex and evolving nature of disability as experienced in diverse, intersectional ways. Findings from this project include insights into challenges faced during collaborative training development, strategies for building inclusive educational practices, and recommendations for institutions aiming to incorporate the voices of students with disabilities into their accessibility initiatives. Suggestions for practice are offered to guide educators in creating accessible, responsive learning environments
Where Digital Accessibility Meets Universal Design: Transforming Classrooms for Multilingual Learners with Disabilities
Get PDFMultilingual learners with disabilities comprise an important population of diverse students that need to be empowered with accessible instructional and assessment materials on their pathways to college, career, and community readiness. These students require integrated supports for both language- and disability-related needs. Conventional approaches to accessibility often fall short in addressing the diverse linguistic, cognitive, and cultural needs of multilingual learners with disabilities. This article examines the intersection of digital accessibility and principles of universal design to create more inclusive and equitable educational environments for these students. Universal design provides a flexible framework that accommodates diverse learning needs by offering multiple means of engagement, representation, and expression. The principles of accessibility have evolved to include linguistic, cognitive, and sensory needs, which are critical for multilingual learners with disabilities. By leveraging digital tools aligned with Web Content Accessibility Guidelines (WCAG), educators can remove barriers to learning and assessment. Additionally, incorporating culturally relevant pedagogy into support systems for multilingual learners with disabilities fosters a more inclusive and affirming learning experience for these students, recognizing their unique cultural identities. The article offers considerations for various interest holders who serve multilingual learners with disabilities and advocates for the co-creation of digital resources by students, educators, and developers to ensure they meet real-world accessibility challenges. Advancements in artificial intelligence are considered as well, as they offer new possibilities for personalized learning experiences that support linguistic diversity and accessibility. By addressing the complex needs of multilingual learners with disabilities through proactive accessibility strategies, educators can create classrooms that are not only legally compliant but also equitable, culturally responsive, and empowering for all students. This approach is essential for dismantling barriers and fostering the academic success and social inclusion of multilingual learners with disabilities
An AI-Driven Framework for Assessing Intersection Infrastructure and Accessibility
Get PDFBackground: Intersections serve as vital nodes within transportation networks, facilitating the movement of pedestrians. However, their effectiveness often hinges on the quality of their infrastructure and accessibility. Furthermore, it is expensive and time-consuming to collect infrastructure data, yet is crucial for creating a safe and efficient urban landscape.
Objective: Develop an AI-driven model that leverages Google Street View to provide detailed information about intersections, helping city planners identify infrastructure and accessibility issues and supporting improvements to create safer, more accessible intersections for people of all abilities