1,117 research outputs found
Software breadboard study
The overall goal of this study was to develop new concepts and technology for the Comet Rendezvous Asteroid Flyby (CRAF), Cassini, and other future deep space missions which maximally conform to the Functional Specification for the NASA X-Band Transponder (NXT), FM513778 (preliminary, revised July 26, 1988). The study is composed of two tasks. The first task was to investigate a new digital signal processing technique which involves the processing of 1-bit samples and has the potential for significant size, mass, power, and electrical performance improvements over conventional analog approaches. The entire X-band receiver tracking loop was simulated on a digital computer using a high-level programming language. Simulations on this 'software breadboard' showed the technique to be well-behaved and a good approximation to its analog predecessor from threshold to strong signal levels in terms of tracking-loop performance, command signal-to-noise ratio and ranging signal-to-noise ratio. The successful completion of this task paves the way for building a hardware breadboard, the recommended next step in confirming this approach is ready for incorporation into flight hardware. The second task in this study was to investigate another technique which provides considerable simplification in the synthesis of the receiver first LO over conventional phase-locked multiplier schemes and in this approach, provides down-conversion for an S-band emergency receive mode without the need of an additional LO. The objective of this study was to develop methodology and models to predict the conversion loss, input RF bandwidth, and output RF bandwidth of a series GaAs FET sampling mixer and to breadboard and test a circuit design suitable for the X and S-band down-conversion applications
Houston Security Camera Ordinance: Reasonable Safety Measure or Orwellian Surveillance
A new ordinance went into effect in Houston, Texas in July 2022, which looks to leverage technology and require certain businesses to install surveillance cameras at their own cost and turn footage over to the police on demand without a warrant. The ordinance specifically requires bars, nightclubs, convenience stores, sexually oriented businesses, and game rooms to install surveillance cameras, with accompanying lighting at all places where customers are permitted, keep the cameras running at all times, even when the business is closed, and store the footage for at least thirty days, all at the expense of the business owners. The ordinance looks to use the video camera footage to help law enforcement in identifying and apprehending persons alleged to have committed violent crimes which have been on the rise in Houston in recent years. Advocates say that the requirements imposed by the ordinance are reasonable safety measures which will help to deter crime in the city. Critics of the ordinance argue that this is an Orwellian measure which unfairly targets certain businesses and forces small business owners to bear the cost of these measures. The requirement of the ordinance to turn over video surveillance footage to law enforcement on demand without a warrant, calls in to question several issues around the Fourth Amendment, privacy, and property rights. This note will explore the background of the ordinance, who the ordinance impacts, and potential legal questions the ordinance raises
LC Subject Headings, FAST Headings, and Apps: Diversity Can Be Problematic In the 21st Century
In this chapter, the author discusses and evaluates the effort to study and update relevant ethnic, racial, and other diverse subject headings. This discussion includes the work of the Library of Congress and software vendors. The author encourages for the technical services community to develop, use, and change subject headings to accurately reflect society
Archaeology, Mormonism, and the Claims of History
The Church of Jesus Christ of Latter-day Saints “Mormonism”) is one of the fastest growing religions in the world today (Stark 1998a, b), including India, where membership (especially in the South) has increased dramatically over the last decade. With notable exceptions (e.g., Leone 1979; Murphy 1999; Olsen 2000; Rodseth and Olsen 2000), however, Mormonism has been neglected in the anthropology of religion. The purpose of this paper is to act as a corrective to this imbalance by addressing changes in Mormonism’s conception of itself as a world religion that makes certain claims about its own history. Specifically, I examine Mormonism’s claim – possibly unique among the major world religions -- that a large part of its scriptural tradition took place in ancient America. My purpose is not to explore the history of this claim, nor to take any position on its validity. Instead, I explore the claim itself as it unfolds with reference to a particular domain, Mesoamerican archaeology, and a particular object – the so-called “Tree of Life” stone (also known as Izapa Stela Five) that some Mormons occasionally cite as archaeological evidence for the ancient American origins of the Book of Mormon
School Social Workers: A Call to Action in Support of Human Rights
The global climate of extremism and direct attacks on marginalized groups such as LGBTQI persons, Muslims, women, immigrants, and refugees creates a need at this critical juncture for school social workers to ground themselves in the international definition of social work, which defines social work as a human rights profession. While there are many challenges to upholding human rights conventions across the world, a human rights framework can assist school social workers in promoting human rights and advocating for vulnerable and marginalized populations. In the context of global migration, children can be especially vulnerable to human rights violations. A human rights approach calls on school social workers to practice in a way that allows for maximum participation of service users in decisions that affect them, addresses power differentials, considers the social context, and privileges an intersectional, strengths based, trauma informed, and recovery oriented approach
Electronics and Chemistry: Varying Single Molecule Junction Conductance Using Chemical Substituents
We measure the low bias conductance of a series of substituted benzene
diamine molecules while breaking a gold point contact in a solution of the
molecules. Transport through these substituted benzenes is by means of
nonresonant tunneling or superexchange, with the molecular junction conductance
depending on the alignment of the metal Fermi level to the closest molecular
level. Electron-donating substituents, which drive the occupied molecular
orbitals up, increase the junction conductance, while electron-withdrawing
substituents have the opposite effect. Thus for the measured series,
conductance varies inversely with the calculated ionization potential of the
molecules. These results reveal that the occupied states are closest to the
gold Fermi energy, indicating that the tunneling transport through these
molecules is analogous to hole tunneling through an insulating film.Comment: 14 pages, 4 figure
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