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Why Linear Faults Have Fewer Earthquakes: A Geometric Explanation
No full textEarthquakes usually occur in the vicinity of fault lines. Until recently, geophysical analysis implied that the fault shape should not strongly affect the frequency of its earthquakes. However, recent statistical analysis has shown that faults whose shape is close to linear experience much fewer earthquakes than faults of more complex shape. Based on this empirical fact, researchers have adjusted the corresponding geophysical models, so the updated models do explain this newly discovered phenomenon. The experience of geophysics shows that the updated model will probably need to be updated again when new data appears. It is therefore desirable to come up with an explanation of the above phenomenon that does not depend on the specifics of the underlying physical model. In this paper, we provide such an explanation -- it is based only on the corresponding geometric symmetries and on the general physical ideas related to symmetries and their violations
La dos espíritus
No full textA través de la novela La dos espíritus se examina la representación de las masculinidades diversas, disidentes de la heteronormatividad. El texto dialoga con la novela El vampiro de la colonia Roma (1978) de Luis Zapata y otras representaciones del personaje queer. A través de la protagonista Cayetana, una mujer transgénero y mediante el formato de una larga entrevista que le realiza el periodista Josué, la novela explora temas de identidad, marginalización y resistencia
Productivity within Groups: An Analysis of Shirking in High School Cross Country Competitions
Get PDFUsing enrollment based classification realignments for high school cross country running competitions in the state of Texas, we analyze the impact of changes in the intensity of competition on individual and team performance. The analysis demonstrates significant improvement in the performance of teams promoted to more competitive classifications in the boys’ division but does not yield similar results in the girls’ division. We also analyze the impact on runners according to their rankings within teams and find improvements to be greater for runners ranking lower relative to team leaders driven by heterogeneity in motivation based on ability or the sequential stage. If the objective is to maximize runner potential, our findings suggest that the time summation method provides stronger incentive alignment than the rank-summation method in team competition. The general implications are significant for determining optimal incentive structures in team-based production processes with significant spillovers from individual performance
Entrepreneurial Orientation and Organizational Performance: Exploring Moderated Curvilinear Relationships
Get PDFEmpirical investigations of the EO–firm performance relationship have typically focused on small and medium-sized ventures and have relied on survey data. Will the shape of the relationship curve hold for firms that moved past the ‘ventures’ phase? Our study investigates a sample of 11,843 small, medium, and large publicly listed firms drawn from the COMPUSTAT database. We confirm the existence of a U-shaped EO-performance relationship, and our analysis offers new evidence on the role of EO in SMEs versus large firms. Contrary to conventional wisdom, our sample of SMEs displayed lower levels of EO than large firms, and large firms were found to be five times more likely to have high rather than low levels of EO. Additionally, environmental dynamism was found to influence the U-shaped relationship. We offer a deeper understanding and new insights on the moderating role of environmental dynamism. For example, the U-shaped EO-performance curves for high and low environmental dynamism were found to intersect, contradicting prior arguments that different levels of environmental dynamism will deliver differing EO-performance relationships. Finally, this study offers evidence of the interpretive advantages of using financial proxies to reflect study variables, compared to traditional approaches like surveys
Three Applications of Geometric Reasoning: Why Metastasis Is Mostly Caused by Elongated Cancer Cells? How Body Shape Affects Curiosity? Why Ring Fractures in Ice?
No full textIn this paper, we describe three applications of geometric reasoning to important practical problems ranging from micro- to macro-level. Specifically, we use geometric reasoning to explain why metastasis is mostly caused by elongated cancer cell, why curiosity in fish is strongly correlated with body shape, and why ring-shaped fractures appear in Antarctica
Enhancing Predictive Accuracy in Noisy Data: A Robust Gradient Boosting Approach
No full textThis thesis aims to enhance the gradient boosting technique, a well-known machine learning method, in a regression setup. Gradient boosting techniques implement sequential weak learners, in this case, shallow trees that contribute to the model with a small percentage. The traditional gradient boosting approach uses regression trees that choose thresholds based on minimizing variance and makes predictions based on the mean of the target variable for the observations contained within each node. The residual sum of squares (RSS) and mean metrics are sensitive to outliers, which makes the model\u27s predictions less robust. Outliers influence the predictions, resulting in a model that does not adequately represent regular data observations. Therefore, the proposed solution to this problem is to use the median absolute deviation (MAD), a robust spread metric instead of variance, and to make predictions within each region based on the median instead of the mean
Why Kolmolgorov-Arnold Networks (KAN) Work So Well: A Qualitative Explanation
No full textIn the usual deep neural network, weights are adjusted during training, but the activation function remains the same. Lately, it was experimentally shown that if, instead of using the same activation function always, we train the activation functions as well, we get a much better results -- i.e., for the networks with the same number of parameters, we get a much better accuracy. Such networks are called Kolmogorov-Arnold networks. In this paper, we provide a general explanation of why these new networks work so well
Interview no. 1787
No full textMr. Antonio Marín is a former resident of El Segundo Barrio. Arriving to the United States from Jalisco, Mexico, at the age of 5, he recalls entering for the first time through the Santa Fe port of entry from Ciudad Juárez to downtown El Paso. He and his family first rented a single-room apartment and then moved to a two-room flat in a tenement. Antonio attended Aoy Elementary and Bowie High School. He talks about how Southside El Paso was a segregated community of Mexicans and Blacks, where they would get along well in places like Douglass Elementary. Mr. Marín describes this Southside area as a densely populated one, with 50,000 people living there. Many tenements no longer exist
In this story, Segundo Barrio is described as a barrio of barrios due to its multiplicity of spaces and diversity of population and their identities. Some outstanding characters, like Father Rahm, did a great job within such a particular community. The KC (Knights of Columbus), grocery stores and recreational centers like Our Lady of Youth were some of the most important social nodes for gathering.
He remembers how, due to the lack of parks, streets had to be closed to hold public events; the only park he refers is Armijo Park. The Boys Club, directed by Salvador “El Huevo” Ramírez, was a good place for little kids from all the smaller barrios to gather. Because of a lack of parks, children and youth played touch football on the streets, a dangerous practice.
Mr. Marín describes the lack of services, such as gas, air conditioning, or bathrooms in the tenements, where mostly big families lived. Working class people from the factories and cotton fields were the main population of Segundo Barrio. Mr. Marín himself worked in the onion fields as a summer job when a teenager.
During the Vietnam war, many young men from Segundo Barrio were deployed, including Antonio\u27s older brother, who died in the war, in addition to another 6 Bowie former students. He became very political and chose not to go to Vietnam.
Mr. Marín says that there was more of a sense of community back then, when people used to take care of each other in the barrio. Back then, there were trees, bushes, and water everywhere, now lost because of governmental neglect on both sides of the border. On the other hand, organizations such as Our Lady Youth Center Center, the Alley Cats, Chihuahua Cougars, the Blue Stars of El Paso Street and the Ochoa Sun Devils tried to always assist the community in the struggle for better living conditions, like housing codes, education and recreation.
Mr. Marín also describes the struggle to get rid of Spanish detention in schools in El Paso, as well as in other places such as Sierra Blanca and East L.A. In that same context, he participated in organizing a counter-conference to the Conference on Poverty that took place in El Paso in 1967. In the context of the Chicano Movement, El Paso, then got connected with local and nation-wide organizations and struggles, supporting other fights such as the Grape Boycott, the Farah Strike, as well as the Tenements Union and the opening of clinics in El Paso. The Housing projects in El Segundo Barrio area, as described by Antonio Marín, were “like concentration camps”, meaning that they were crowded and non-hospitable. People then started moving away from the barrio and El Paso.
MAYA (Mexican American Youth Association) branches, or “chapters” spread across El Paso, to the point of including women (from Ysleta) that wanted to join the organization. Importantly, Armijo was the point of reunion for the meetings. Some of these organizations (like the Alley Cats) could direct scholarships to barrio youth to attend college, particularly UTEP. These connections though political activism led to youths from El Paso going to the University of Colorado at Boulder, to pursue a degree, since Salvador Ramirez, a Chicano activist from El Paso, was working there. This was a time when barely 15-20% of college students were Chicanos/Mexicanos, so these efforts positively impacted this sector of the community.
Speaking of schools in El Paso, Mr. Marín describes the system as one control by an oligarchy, where Mexicans had a place as teachers, but not higher positions like principals or counselors. That has changed over time, and Mr. Marín thinks that it is because of the social movements. The oligarchy, he recalls, has had an active role in the displacement of poor people in South El Paso, to open the gate for gentrification and capitalist interests
Enhancing the Utility of Unmanned Autonomous Vehicles (UAVs) with Model-Based Systems Engineering (MBSE) and Modular Open Systems Approach (MOSA)
No full textUnmanned Autonomous Vehicles (UAVs) have emerged as versatile tools with significant implications across various industries, particularly in defense. The technological advancements in UAVs have revolutionized military operations, surveillance, and reconnaissance capabilities. However, there exist challenges such as environmental factors affecting sensor and flight performance, limited battery life restricting flight durations, and payload capacity constraints impeding task efficiency.This paper delves into the importance of UAVs in different industries, specifically focusing on their pivotal role in the Department of Defense. It emphasizes the necessity of technological upgrades to overcome current challenges and proposes the adoption of a Modular and Open System Approach (MOSA) to drive innovation and streamline UAV design processes. Implementing MOSA can tackle system complexity, enhance interoperability, and optimize development procedures within the UAV sector. Moreover, the paper introduces Model-Based Systems Engineering (MBSE) as a methodology for successfully incorporating MOSA into UAV design. This approach offers a visual representation of system components and their interactions, aiding in identifying components suitable for modular design based on key principles: Encapsulation, Loose Coupling, Abstraction, Single Responsibility Principle, and High Cohesion. The anticipated outcomes of this initiative aim to foster innovation, collaboration, and system evolution. A case study featuring a quadcopter UAV tailored for inspection missions illustrates the practical application of MBSE and MOSA principles by utilizing SysML Cameo software in UAV development
Border Soundscapes: Latinidad, Belonging, and Sense of Place in the Paso del Norte Region.
No full textThis dissertation explores the acoustic ecologies of the Juárez-El Paso border, investigating how soundscapes shape and reflect the cultural identity, sense of belonging, and sense of place within this unique transnational region. Guided by the theoretical lenses of belonging (Kohut, Tajfel, Turner, Hooks), sense of place (Feld & Basso), and habitus (Bourdieu), the research takes a phenomenological approach, informed by Merleau-Ponty\u27s concepts of perception and Ceraso\u27s notion of embodied listening. The study analyzes soundscape samples through Krause\u27s categories of biophonies, geophonies, and anthropophonies, uncovering how these sounds contribute to the development of Latino identity and cultural cohesion in the borderlands.Focusing on the historical, sociocultural, pedagogical, artistic, and environmental dimensions of sound, the research reveals how these auditory experiences create a shared sense of identity and community among border residents, despite the sociopolitical divisions that separate them. By examining specific sound events, such as linguistic dimensions and code-switching in Lucha Libre poetry, cultural events, street vendors, and singers, the study highlights the historical, aesthetic, and symbolic values that these sounds carry, demonstrating their role as markers of resilience, transformation, and sonic cultural memory. The findings suggest that soundscapes in the Juárez-El Paso border are not merely background noise but are integral to understanding the complexities of border identity and belonging. The dissertation contributes to the field of Rhetoric laying the foundations for a specific approach in Border Sonic Rhetorics, offering a nuanced understanding of how sounds mediate social interactions and cultural identities in border regions. This work emphasizes the importance of including the acoustic dimension in border studies, providing a framework for future research on the role of sound in shaping the lived experiences of border communities