Covering Radius 1985-1994

We survey important developments in the theory of covering radius during the period 1985-1994. We present lower bounds, constructions and upper bounds, the linear and nonlinear cases, density and asymptotic results, normality, specific classes of codes, covering radius and dual distance, tables, and open problems

New Approaches to the Analysis and Design of Reed-Solomon Related Codes

The research that led to this thesis was inspired by Sudan's breakthrough that demonstrated that Reed-Solomon codes can correct more errors than previously thought. This breakthrough can render the current state-of-the-art Reed-Solomon decoders obsolete. Much of the importance of Reed-Solomon codes stems from their ubiquity and utility. This thesis takes a few steps toward a deeper understanding of Reed-Solomon codes as well as toward the design of efficient algorithms for decoding them. After studying the binary images of Reed-Solomon codes, we proceeded to analyze their performance under optimum decoding. Moreover, we investigated the performance of Reed-Solomon codes in network scenarios when the code is shared by many users or applications. We proved that Reed-Solomon codes have many more desirable properties. Algebraic soft decoding of Reed-Solomon codes is a class of algorithms that was stirred by Sudan's breakthrough. We developed a mathematical model for algebraic soft decoding. By designing Reed-Solomon decoding algorithms, we showed that algebraic soft decoding can indeed approach the ultimate performance limits of Reed-Solomon codes. We then shifted our attention to products of Reed-Solomon codes. We analyzed the performance of linear product codes in general and Reed-Solomon product codes in particular. Motivated by these results we designed a number of algorithms, based on Sudan's breakthrough, for decoding Reed-Solomon product codes. Lastly, we tackled the problem of analyzing the performance of sphere decoding of lattice codes and linear codes, e.g., Reed-Solomon codes, with an eye on the tradeoff between performance and complexity.</p

Exploiting Spatio-Temporal Coherence for Video Object Detection in Robotics

This paper proposes a method to enhance video object detection for indoor environments in robotics. Concretely, it exploits knowledge about the camera motion between frames to propagate previously detected objects to successive frames. The proposal is rooted in the concepts of planar homography to propose regions of interest where to find objects, and recursive Bayesian filtering to integrate observations over time. The proposal is evaluated on six virtual, indoor environments, accounting for the detection of nine object classes over a total of ∼ 7k frames. Results show that our proposal improves the recall and the F1-score by a factor of 1.41 and 1.27, respectively, as well as it achieves a significant reduction of the object categorization entropy (58.8%) when compared to a two-stage video object detection method used as baseline, at the cost of small time overheads (120 ms) and precision loss (0.92).</p

A Mixed-Method Study on the Walkability of Streets in Hospital-Anchored Neighborhoods

The field of healthcare design is adopting planning and design principles from the Healthy Communities movement to connect hospitals to their adjacent communities. This research explores the impact of neighborhood and street design on the walkability of Hospital-Anchored Neighborhoods (HANs), a concept integrating hospitals and satellite services with their surrounding communities to enhance public health. Walkability, a crucial marker of healthy and vibrant communities, was investigated through a mixed-method study across three HANs. A comprehensive Walkability Framework with 17 built environment dimensions was developed from the literature to inform data collection utilizing GIS archival data, ethnographic observations, street audits, and interviews. Findings indicate that multiple factors influence walkability at the neighborhood, street, building, and experiential levels. The walkability scores differed from those provided by the Environmental Protection Agency’s National Walkability Index. 6 of the 7 street-level dimensions (compactness, mixed-uses, imageability, enclosure, human scale, and transparency of streets, but not complexity) were correlated with pedestrian counts. Out of 40 street features studied, 27 significantly influenced the number of pedestrians on the street. Active and inactive building uses also showed significant variance in pedestrian counts. Furthermore, pedestrian interviews highlighted convenience, comfort, and safety, not visual attraction, as key experiential factors influencing walkability. This research underscores the importance of built environment factors in creating walkable streets on health campuses. It advocates for including specific design features, active street life planning, pleasant outdoor experiences, and safety measures. This study presents a Street Walkability Framework and evidence-based design guidelines to improve walkability in Hospital-Anchored Neighborhoods

LIPIcs, Volume 261, ICALP 2023, Complete Volume

LIPIcs, Volume 261, ICALP 2023, Complete Volum

Characterizing The Undergraduate Planetarium Learning Environment & Investigating Obliquity-Induced Changes to Heavy Ion Loss At Mars

Three studies are described in this work detailing research efforts in two avenues of astrophysical and planetary science. PLUS (the PLanetarium Usage Survey) and PLOBS (the PLanetarium OBservation Study) investigated the use of the planetarium learning environment in order to characterize the environment's use in the education of undergraduate learners in the astrophysical and planetary sciences. PLUS, a nationwide survey and interview protocol, established an understanding of present-day collegiate planetarium use: what contents were shown, how often were planetariums being used, and how and why were particular content styles chosen for presentation to undergraduates. PLOBS, a university-specific survey and observation campaign, investigated how a university faculty used the planetarium: why did they integrate planetarium visits in their courses, how did their lessons commence, and how did the planetarium environment compare to its complementary classroom environment. Together, PLUS and PLOBS suggested a collegiate planetarium learning experience focused predominantly on non-major, lower division astronomy content presented to learners for the purpose of providing immersive, visual scaffolding. Learning processes in the planetarium showed a high degree of overlap with those in the classroom setting and a measurable decrease in certain reformed practices, suggesting planetarium lessons involve more passive learning strategies than those in the classroom. MOP (the Mars Obliquity Project) investigated the effects of the chaotic Martian obliquity cycle on the rate at which Mars loses its atmosphere to space. Using a multifluid, magnetohydrodynamic simulator engine to probe six experimental cases of the Mars-solar wind interaction, MOP analyzed the changes to the escape of three heavy ion species (O+, O2+, and CO2+) from Mars with the remnant crustal fields on the planet's night side as the planet's obliquity angle was changed. Escape rate calculations demonstrated a measurable, but minor effect on heavy ion loss as a function of planetary obliquity angle, with the heaviest ions showing the greatest sensitivity to changing planetary obliquity. Implications of calculated escape rates suggest magnetic shielding of atmospheric particles is a minor player in the atmospheric evolution of a planet, with gravity being the dominating factor.</p