El Camino College

This paper presents a high-performance Q/Vband dual-polarized Cassegrain reflector antenna developed for next-generation space communication ground station applications. The antenna operates over the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$37-51.5 \text{GHz}$</tex> frequency range, delivering a gain of 58 dBi, a half-power beamwidth of 0.2 degrees, and sidelobe levels at least 15 dB below the main lobe nominally. The antenna system comprises a 2.4-meter (96-inch) diameter main reflector, a sub-reflector, a feedhorn, and a complex feed network that integrates a linear-to-circular polarizer, an orthomode transducer (OMT), and two frequency diplexers. Due to the electrically large aperture, performance testing was conducted in a newly developed nearfield measurement range capable of characterizing antennas up to 3.0 meters in diameter at frequencies up to 110 GHz. The measured results confirm that the fabricated antenna meets the original design specifications. Achieving the antenna's high performance, along with accurate pattern and gain measurements, involves substantial technical, manufacturing, and testing challenges. These accomplishments represent a state-of-the-art milestone in the design and production of electrically large antennas operating in this frequency range.

Machine learning models find significant importance in Geographic Information Systems relating to agriculture. UAV-derived orthomosaics, digital height maps, and vegetative indices provide valuable data for predicting crop yields across regions. These insights can support informed decision-making for farmers and stakeholders. While machine learning excels at analyzing large datasets, training and validating models on randomly distributed spatial data may introduce uncertainty and bias due to spatial autocorrelation. This research evaluates the effectiveness of random and spatial cross-validation (CV) techniques for crop yield prediction using machine learning models. The study utilizes dry yield data from hybrid maize collected over two years across two fields in Waseca, MN. Feature selection was employed to reduce model complexity when analyzing multiple vegetative indices. Results indicate that random CV outperforms spatial CV, and among the models tested, Extreme Gradient Boosting achieved the highest predictive performance.

In Sartre’s 1946 article “The Humanism of Existentialism,” Sartre places existentialists into two categories, Christian or atheist, and contends that existentialism works differently for each of them. This paper argues that such a distinction should not have been made because existentialist beliefs, views, and themes do not differ based on one’s religiosity. This paper specifically examines three examples in Sartre’s article which undermine his position, and further argues that Sartre made an equivocation fallacy by conflating two different types of essence, one’s innate essence and one’s character essence. The paper then explores six central existentialist themes to demonstrate that in their existentialist beliefs both the theist and the atheist agree. Those six themes are authenticity, sincerity vs. bad faith, the absurdity of life, the meaning of life, choice, and responsibility. The paper also examines the issue of moral objectivity vs. non-objectivity, and argues that not only is this not an existentialist issue, but even if it were one’s belief on moral objectivity does not cleanly correspond to one’s religious beliefs, so here again there is no basis to distinguish the Christian and the atheist. The paper concludes that any disagreement between existentialists who are Christian and those who are atheist comes down to differences in their religious beliefs, not their existentialist views.

William Paley’s classic version of the Teleological Argument contends that just as a watch is ordered for a purpose and we rightfully conclude that it had a creator who ordered it, the universe is also ordered in many ways and for a variety of purposes, so we should similarly conclude that it had a creator, God, who ordered it. This paper contends that Paley committed the fallacy of equivocation when he lumped various types of order together as if they had no differences. The watch’s operations are an example of Intentional Order—order created intentionally by a conscious agent for a specific purpose. The universe, on the other hand, until it had conscious and purposeful beings such as human beings, had exhibited only Ramseyian Order, Purposeless Order, and Functional Order. These three types of order can be explained by science in naturalistic terms, and therefore it is superfluous to appeal to a conscious Creator-God, let alone a supernatural one. Additionally, the paper asserts that the best scientific evidence indicates that the universe has always been and still is primarily disordered, and further argues that the natural laws, contrary to popular belief, are not ordered. Moreover, the order that is present is riddled with design flaws. As such, our universe is inconsistent with what one would expect from an Intelligent Designer/God. Therefore both Paley’s analogical argument and all standard versions of the Teleological Argument, which rely on the order present in the universe to argue for the existence of God, fail.

Introduction -- Chapter 1: For a Foundation -- Chapter 2: Modal Skepticism and Material Causation -- Chapter 3: The Geometric Argument -- Chapter 4: Finitude, Topology, and Arbitrariness -- Chapter 5: Argument from Arbitrary Limits -- Chapter 6: Varieties of Naturalism -- Chapter 7: For a Personal Foundation -- Chapter 8: How Naturalism Could Explain Morality, Rationality, and Intentionality -- Chapter 9: Foundational Mind Theory Extended -- Chapter 10: Filling out a Naturalistic Picture via Spinoza and Russell -- Chapter 11: How the Best of Naturalism Fits Inside a Foundational Mind -- Chapter 12: Reflection -- Chapter 13: A Perfectly Good Foundation: Some Reasons for Doubt -- Chapter 14: The Great Story Theodicy -- Chapter 15: Questioning the Story -- Chapter 16: How to See the Good in the Foundation -- Epilogue.

This paper proposes two thought experiments to demonstrate that our current treatment of animals is immoral. The first thought experiment involves aliens coming to earth and doing to us what we do to animals—eating us, confining us in farms and zoos, doing experiments on us, etc. Drawing on the latest scientific research on the abilities of animals, this thought experiment seeks to show that there are more relevant similarities between human beings and animals than most people realize, and that the differences between us and many other animals are not morally relevant. Moreover, this thought experiment attempts to appeal primarily to our sense of justice by tapping into our emotions for ourselves rather than to the usual approach which appeals to our emotions for animals. The second thought experiment is similar to the first, but more centrally emphasizes the idea of luck. It will, in part, take an approach recommended by Donald VanDeVeer to employ Rawl’s veil of ignorance to mask not only our natural and social starting places, but also our species—whether we are human or of another species. However, one serious objection made to VanDeVeer’s approach will be circumvented, namely, that it is difficult to imagine ourselves as an animal. Rather, we will imagine that evolution has made it so we are not the smartest and most powerful species on earth. This thought experiment invites us to ask ourselves that if there were only two species to consider and we were the less advanced of the two, would we still not expect to be treated with dignity and respect? Both analogies ultimately challenge us to ask the following question: What principles of justice would we choose to govern the interactions between species if we were not the most intelligent and powerful species on earth?

Abstract In the Salton Trough, CA, five rhyolite domes form the Salton Buttes: Mullet Island, Obsidian Butte, Rock Hill, North and South Red Hill, from oldest to youngest. Results presented here include 40Ar/39Ar anorthoclase ages, 238U‐230Th zircon crystallization ages, and comparison of remanent paleomagnetic directions with the secular variation curve, which indicate that all domes are Holocene. 238U‐230Th zircon crystallization ages are more precise than but within uncertainty of 40Ar/39Ar anorthoclase ages, suggesting that zircon crystallization proceeded until shortly before eruption in all cases except one. Remanent paleomagnetic directions require three eruption periods: (1) Mullet Island, (2) Obsidian Butte, and (3) Rock Hill, North Red Hill, and South Red Hill. Borehole cuttings logs document up to two shallow tephra layers. North and South Red Hills likely erupted within 100 years of each other, with a combined 238U‐230Th zircon isochron age of: 2.83 ± 0.60 ka (2 sigma); paleomagnetic evidence suggests this age predates eruption by hundreds of years (1800 cal BP). Rock Hill erupted closely in time to these eruptions. The Obsidian Butte 238U‐230Th isochron age (2.86 ± 0.96 ka) is nearly identical to the combined Red Hill age, but its Virtual Geomagnetic Pole position suggests a slightly older age. The age of aphyric Mullet Island dome is the least well constrained: zircon crystals are resorbed and the paleomagnetic direction is most distinct; possible Mullet Island ages include ca. 2300, 5900, 6900, and 7700 cal BP. Our results constrain the duration of Salton Buttes volcanism to between ca. 5900 and 500 years.