A search for binary stars using speckle interferometry

Fifteen suspected double stars from the Hipparcos satellite are analyzed to find new binary stars. The measures are derived from speckle observations taken with the Wisconsin-Indiana-Yale-NOAO (WIYN) 3.5 meter telescope located at Kitt Peak, Arizona. My research project was based on my Hypothesis: Speckle Interferometry allowed for diffraction-limited images to be captured by the WIYN telescope. Analysis of the speckle data from the WIYN allowed for the detection of the orbital motion of gravitationally bound binary stars and the detection of new double stars. Data from the WIYN telescope was taken using a low noise fast readout CCD array, which takes exposures at 30-50 ms each. The analysis program used was written by Dr. Horch and uses speckle interferometry and information from the bispectrum to combine each 30-50 ms speckle frame into a single image of the star system. Reliable astrometry has been obtained on a system of magnitude difference of 5.3 with this CCD system. For the CCD, the root mean square (rms) deviation of residuals was found to be 3.5 milliarcseconds (mas) in separation and 1.2º in position angle. The advantages of speckle interferometry are that: Short exposure images effectively freeze atmospheric fluctuations so that the diffraction limited image can be recovered. Speckle frames are combined using image analysis to create diffraction limited images High resolution is needed to separate close binary stars The group of stars studied is a small subset of double stars discovered by the Hipparcos satellite in 1991. Orbital motion was detected in these binary stars using a 3-year baseline data from WIYN and position information from Hipparcos in 1991. The Hipparcos satellite discovered about 6000 new or newly suspected double star systems

Framework for Electroencephalography-based Evaluation of User Experience

Measuring brain activity with electroencephalography (EEG) is mature enough to assess mental states. Combined with existing methods, such tool can be used to strengthen the understanding of user experience. We contribute a set of methods to estimate continuously the user's mental workload, attention and recognition of interaction errors during different interaction tasks. We validate these measures on a controlled virtual environment and show how they can be used to compare different interaction techniques or devices, by comparing here a keyboard and a touch-based interface. Thanks to such a framework, EEG becomes a promising method to improve the overall usability of complex computer systems.Comment: in ACM. CHI '16 - SIGCHI Conference on Human Factors in Computing System, May 2016, San Jose, United State

Urban Agriculture and Sustainability in Chicago

Sustainability is increasingly informing the organization of urban life. In the past 15 years, cities have sought to alleviate the dual effects of environmental degradation and a changing economy by introducing sustainable development initiatives. Policy makers and environmental activists have often praised these efforts, pointing to the enhancement of quality of life, the mitigation of industrial pollution, and these initiatives\u27 capacity to address poverty in a post-welfare state. Most popular depictions of the experiences of sustainability come from the perspective of white, middle class, college-educated volunteers and, increasingly, social entrepreneurs such as artisans, farmers, and other producers connected to local foods movements. Yet what is missing is the experiences and perspectives of low-wage earners, job trainees, and black youth who participate in various urban sustainable development initiatives. This is important because sustainability initiatives have historically benefitted white middle class people often at the expense of poor people of color. In other words, sustainable development has reproduced and exacerbated existing inequality. This research provides answers to debates in urban and environmental sociology about how to achieve more equitable distributions of power in order to make the production of urban environments more inclusive

Balling on a Budget

This Zine takes a dive into the gender pay gap women face in professional sports. The gender pay gap is an issue that women all around face, but it’s something that needs to be talked about more when it comes to sports. It breaks down the difference between paychecks and the award amount between men and women sports. It also goes over some of the actions being taken to diminish the pay gap.https://digitalcommons.butler.edu/spring_2023/1006/thumbnail.jp

Counting atoms in a deep optical microtrap

We demonstrate a method to count small numbers of atoms held in a deep, microscopic optical dipole trap by collecting fluorescence from atoms exposed to a standing wave of light that is blue detuned from resonance. While scattering photons, the atoms are also cooled by a Sisyphus mechanism that results from the spatial variation in light intensity. The use of a small blue detuning limits the losses due to light assisted collisions, thereby making the method suitable for counting several atoms in a microscopic volume

Simulation of alnico coercivity

Micromagnetic simulations of alnico show substantial deviations from Stoner-Wohlfarth behavior due to the unique size and spatial distribution of the rod-like Fe-Co phase formed during spinodal decomposition in an external magnetic field. The maximum coercivity is limited by single-rod effects, especially deviations from ellipsoidal shape, and by interactions between the rods. Both the exchange interaction between connected rods and magnetostatic interaction between rods are considered, and the results of our calculations show good agreement with recent experiments. Unlike systems dominated by magnetocrystalline anisotropy, coercivity in alnico is highly dependent on size, shape, and geometric distribution of the Fe-Co phase, all factors that can be tuned with appropriate chemistry and thermal-magnetic annealing

Verifying and Synthesizing Constant-Resource Implementations with Types

We propose a novel type system for verifying that programs correctly implement constant-resource behavior. Our type system extends recent work on automatic amortized resource analysis (AARA), a set of techniques that automatically derive provable upper bounds on the resource consumption of programs. We devise new techniques that build on the potential method to achieve compositionality, precision, and automation. A strict global requirement that a program always maintains constant resource usage is too restrictive for most practical applications. It is sufficient to require that the program's resource behavior remain constant with respect to an attacker who is only allowed to observe part of the program's state and behavior. To account for this, our type system incorporates information flow tracking into its resource analysis. This allows our system to certify programs that need to violate the constant-time requirement in certain cases, as long as doing so does not leak confidential information to attackers. We formalize this guarantee by defining a new notion of resource-aware noninterference, and prove that our system enforces it. Finally, we show how our type inference algorithm can be used to synthesize a constant-time implementation from one that cannot be verified as secure, effectively repairing insecure programs automatically. We also show how a second novel AARA system that computes lower bounds on resource usage can be used to derive quantitative bounds on the amount of information that a program leaks through its resource use. We implemented each of these systems in Resource Aware ML, and show that it can be applied to verify constant-time behavior in a number of applications including encryption and decryption routines, database queries, and other resource-aware functionality.Comment: 30, IEEE S&P 201