Star Tracker Geometric Calibration Through Full-State Estimation Including Attitude

A star tracker calibration method using star images is presented in this paper. Unlike previous works, the proposed method estimates all parameters and the attitudes at once in a single least-squares formulation for the optimal calibration, which can be easily converted to a recursive estimation form. In addition, this paper presents a method to estimate the overall star tracker performance for attitude determination from the calibration results. Since the proposed method uses star images only, it can be applied to both on-orbit and ground star tracker calibration. The simulations show improvements in calibration performance about four times compared to the previous calibration method. The calibration experiments with actual star images are conducted to test its application.

Risk in the digital age: Comedian-activists and Trump’s cancel culture

This article contributes to the study of comedians as activists by examining the campaigns by some of America’s most influential figures – Seth Rogan, Jim Carrey, Dave Chapelle, Amy Schumer, Roseanne Barr and Kathy Griffin. To varying degrees, these comedians all use their star images and personal stories to influence public debates through their stand-up, television work, and content on YouTube, Instagram and Twitter. By studying their activities in the media, their press coverage, and public reactions online, this article also presents an original examination of the way ‘Cancel Culture’ manifests, often hindering their activism. This includes identifying the polarizing influence of the ‘Canceller-in-Chief’ former president Donald J. Trump, and the risks suffered by comedian-activists in terms of their reputation, commercial prospects, and even their legality. Specifically, this article suggests that ‘Cancel Culture’ manifests as a spectrum of varying risk which can be shaped by the comedian’s star image and the degree of social transgression in their comedy.

Segmenting Star Images with Complex Backgrounds Based on Correlation between Objects and 1D Gaussian Morphology

Space object recognition in high Earth orbits (between 2000 km and 36,000 km) is affected by moonlight and clouds, resulting in some bright or saturated image areas and uneven image backgrounds. It is difficult to separate dim objects from complex backgrounds with gray thresholding methods alone. In this paper, we present a segmentation method of star images with complex backgrounds based on correlation between space objects and one-dimensional (1D) Gaussian morphology, and the focus is shifted from gray thresholding to correlation thresholding. We build 1D Gaussian functions with five consecutive column data of an image as a group based on minimum mean square error rules, and the correlation coefficients between the column data and functions are used to extract objects and stars. Then, lateral correlation is repeated around the identified objects and stars to ensure their complete outlines, and false alarms are removed by setting two values, the standard deviation and the ratio of mean square error and variance. We analyze the selection process of each thresholding, and experimental results demonstrate that our proposed correlation segmentation method has obvious advantages in complex backgrounds, which is attractive for object detection and tracking on a cloudy and bright moonlit night.

The Point Spread Function Reconstruction –II The Smooth PCA

Accurate shear measurement is a key topic in weak lensing community. Point Spread Function (PSF), which smears the observed galaxy image, plays one of the main roles in the systematic errors in shear measurement and must be treated carefully to avoid bias and errors in cosmological parameters. In this paper, we present new PSF measurement methods, Smooth-PCA (SPCA) and Improved-SPCA (iSPCA), which can reconstruct smooth PSFs with high efficiency. Our methods decompose the star images into smooth principal components by using the Expectation-Maximization-PCA (EMPCA) method, and the smooth principal components are composed by Moffatlets basis functions, which are derived from the Moffat function. We demonstrate our approaches based on simulated Moffat PSFs and PhoSim star images. The constructed smooth principal components show flexible and efficient as the same as EMPCA, and have more stable patterns than EMPCA under noises contamination. We then check the reconstruction accuracy on the shape of PSFs. We find that our methods are able to reconstruct the PSFs at the same precision as the EMPCA method which indicates and iSPCA are promising for weak lensing shear measurement.

Power off-screen

This final chapter uses extrafilmic material, such as fan magazines, to explore the construction and development of Power’s off-screen image throughout his career. The careful manufacture of star images was a device used by studios to attract audiences to films, and ultimately sell tickets and Power received extensive publicity from early on, fan magazines depicting his off-screen life in ways that often resonated with his on-screen persona, particularly in the 1930s. This chapter explores the development of Power’s off-screen image in fan magazines from his bachelor days in the 1930s, his marriage to French actress Annabella and subsequent divorce when he returned from active war duty. His high-profile romance with Lana Turner preceded his marriage to Mexican actress Linda Christian and the birth of their two daughters, before another divorce and remarriage just before his death in 1958. Magazines then ran stories of his sudden death and subsequent birth of his only son, Tyrone Power Jr, a few months later for months to come. Additionally, while Power’s professional acting career began in the theatre in 1933, he returned to regular stage work in the 1950s in a move that was mostly well received by critics as the chapter discusses.

Universal Verification Platform and Star Simulator for Fast Star Tracker Design

Developing star trackers quickly is non-trivial. Achieving reproducible results and comparing different algorithms are also open problems. In this sense, this work proposes the use of synthetic star images (a simulated sky), allied with the standardized structure of the Universal Verification Methodology as the base of a design approach. The aim is to organize the project, speed up the development time by providing a standard verification methodology. Future rework is reduced through two methods: a verification platform that us shared under a free software licence; and the layout of Universal Verification Methodology enforces reusability of code through an object-oriented approach. We propose a black-box structure for the verification platform with standard interfaces, and provide examples showing how this approach can be applied to the development of a star tracker for small satellites, targeting a system-on-a-chip design. The same test benches were applied to both early conceptual software-only implementations, and later optimized software-hardware hybrid systems, in a hardware-in-the-loop configuration. This test bench reuse strategy was interesting also to show the regression test capability of the developed platform. Furthermore, the simulator was used to inject specific noise, in order to evaluate the system under some real-world conditions.

Meningkatkan Ketahanan Duduk Saat Proses Pembelajaran melalui Pemberian Reward kepada Siswa Autisme

This study discusses the analysis of rewording in the form of stickers with star images, in increasing the duration of sitting endurance for autistic students during the learning process. This study used an experimental method with a single subject research approach. The subject of this study was a class VI autistic student who had a low duration of sitting resistance during the learning process in the classroom. Researchers made observations during seventeen meetings, all data were obtained through observation, interviews and action tests which were presented in graphic form. To measure the duration of sitting endurance, the researcher used a stopwarch analysis tool. Overall the results of the research on the initial conditions for five meetings were 2 minutes, 2 minutes, 4 minutes, 3 minutes 3 minutes. Furthermore, in the intervention condition during the seven meetings the researcher gave reword in the form of a star sticker image, the results were 4 minutes, 3 minutes, 4 minutes, 6 minutes, 5 minutes, 7 minutes, 8 minutes. At baseline A2 conditions obtained dudu resistance results After being given the treatment, namely 5 minutes, 5 minutes, 6 minutes, 7 minutes, 9 minutes. The results of this study prove that giving rewords in the form of star stickers in the learning process can increase the duration of sitting endurance for autistic students, but it is necessary to develop further research in this problem in different contexts and issues.

MET-09 Prognosis prediction study of using Susceptibility-weighted imaging in metastatic brain tumors

Background and purpose: MRI is a very useful tool especially for metastatic brain tumor. It can grasp the status of treatment and progress of primary lesion. In this study, we investigated the prognosis by using SWI (Susceptibility-weighted imaging) or T2 *sequences in MRI. Materials and methods: The study includes 69 patients who took a surgical treatment at our hospital from March 2014 to June 2020. Grade ranged from 0 to 2, with 0 defined as high signal intratumor, 1 defined as within 10 dark spots, 2 as almost consists with dark spot intratumor. Results: The median age of the patients was 66 years and 38 males (55%). The primary tumors were lung cancer in 28 cases (40.7%), breast cancer in 12 cases (17.4%), gastrointestinal cancer in 11 cases (15.9%), kidney cancer in 5 cases (7.2%), and others in 13 cases (18.8%). The SWI or T2 star images showed that grade 0 was 23 cases (33%), grade 1 was 18 cases (26%), grade 2 was 28 cases (41%). There were 16 deaths in grade 0 (69.6%), 10 deaths in grade 1 (55.6%), 15 deaths in grade 2 (53.5%). Conclusions: In this study, there was no statistically significant difference in the SWI or T2*-positive group. However, there was a tendency for many long-term survivors in the SWI or T2*-positive group.