TEXTURAL ANALYSIS AND STATISTICAL INVESTIGATION OF PATTERNS IN SYNTHETIC APERTURE SONAR IMAGES

Textural analysis and statistical investigation of patterns in synthetic aperture sonar (SAS) images is useful for oceanographic purposes such as biological habitat mapping or bottom type identification for offshore construction. Seafloor classification also has many tactical benefits for the U.S. Navy in terms of mine identification and undersea warfare. Common methods of texture analysis rely on statistical moments of image intensity, or more generally, the probability density function of the scene. One of the most common techniques uses Haralick’s Grey Level Co-occurrence Matrix (GLCM) to calculate image features used in the applications listed above. Although widely used, seafloor classification and segmentation are difficult using Haralick features. Typically, these features are calculated at a single scale. Improvements based on the understanding that patterns are multiscale was compared with this baseline, with a goal of improving seafloor classification. Synthetic aperture sonar (SAS) data was provided by the Norwegian Research Defense Establishment for this work, and was labeled into six distinct seafloor classes, with 757 total examples. We analyze the feature importance determined by neighborhood component analysis as a function of scale and direction to determine which spatial scale and azimuthal direction is most informative for good classification performance.Office of Naval Research, Arlington, VA , 22217Lieutenant, United States NavyApproved for public release. Distribution is unlimited

RESOLUTION DEPENDENCE OF ACOUSTIC SCATTERING STATISTICS FOR COMPLEX SEAFLOORS

Unmanned underwater vehicles (UUVs) utilize sonar perception to conduct sea floor mapping and target detection operations. However, systems with different resolutions may generate different probability density functions (PDFs) of the magnitude of the complex pressure. An area of research that has not been adequately studied is the effects of resolution manipulation during the post-processing of high-resolution data from complex seafloor environments. This work analyzed synthetic aperture sonar (SAS) data collected from multiple seafloor geomorphologies surrounding Bergen, Norway, to study the resolution dependence of scattering statistics for complex seafloors. Multi-look methods were applied to reduce the resolution. The original data and reduced resolution data were compared in terms of PDF amplitude and evaluated by standard goodness of fit tests with heavy-tailed statistical models that are commonly used in the radar and sonar community, including mixture models. Top-performing physics-based distributions were analyzed by how well they model how background and clutter parameters change with resolution manipulation. Empirical equations and a table of environmental constants were developed to allow a user to understand better how sonar data behaves at a given resolution and bottom type.Office of Naval Research, Arlington, VA, 22217Lieutenant Commander, United States NavyApproved for public release. Distribution is unlimited

Resolution dependence of rough surface scattering using a power law roughness spectrum

Contemporary high-resolution sonar systems use broadband pulses and long arrays to achieve high resolution. It is important to understand effects that high-resolution sonar systems might have on quantitative measures of the scattered field due to the seafloor. A quantity called the broadband scattering cross section is defined, appropriate for high-resolution measurements. The dependence of the broadband scattering cross section, $\sigma_{bb}$ and the scintillation index, $SI$ on resolution was investigated for one-dimensional rough surfaces with power-law spectra and backscattering geometries. Using integral equations and Fourier synthesis, no resolution dependence of $\sigma_{bb}$ was found. The incoherently-averaged frequency-domain scattering cross section has negligible bandwidth dependence. $SI$ increases as resolution increases, grazing angle decreases, and spectral strength increases. This trend is confirmed for center frequencies of 100 kHz and 10 kHz, as well as for power-law spectral exponents of 1.5, 2, and 2.5. The hypothesis that local tilting at the scale of the acoustic resolution is responsible for intensity fluctuations was examined using a representative model for the effect of slopes (inspired by the composite roughness approximation). It was found that slopes are responsible in part for the fluctuations, but other effects, such as multiple scattering and shadowing may also play a role.Comment: 22 pages, 10 figures, preprint version of paper published in the Journal of the Acoustical Society of America, at \url{https://doi.org/10.1121/10.0002974

Isis, Cabbage and Viper : new tools and strategies for designing responsive media

Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2001.Includes bibliographical references (p. 127-132).Responsive media are media that can sense and react intelligently to factors like presentation conditions or equipment, audience identity or profile, direct interaction, history or anticipation of involvement, and so on. The emergence of modern computational devices and communication networks, with their power to manipulate media signals and objects, has spurred the development of new forms of responsive media. But a lack of a broad framework for understanding the characteristics of and motivations for these media has resulted in computer-based design tools that do not mirror the character of our projects and working practices and, in turn, compromise our ability to communicate effectively with these media. This research strives to build such a framework and use it as a foundation for a suite of three new tools that better reflect the multi-layered, multi-sensory, and multi-person nature of responsive media. Aiming to rethink the principles underlying one of the most primary building blocks in the design process, the centerpiece of this suite, Isis, is a new programming language tailored to serve as a basis for responsive media.(cont.) The second tool, Cabbage, is an experiment in employing a purist form of case-based reasoning in a system for creating responsive graphical layouts. Lastly, Viper is a new tool for making responsive video programs that can re-edit themselves to adapt to different viewing situations. These tools seek to enable the development of complex and meaningful input-output relationships through simple, elegant interfaces that emphasize visibility, accessibility, and extensibility.by Stefan Panayiotis Agamanolis.Ph.D

Artist-Programmers and Programming Languages for the Arts

We consider the artist-programmer, who creates work through its description as source code. The artist-programmer grandstands computer language, giving unique vantage over human-computer interaction in a creative context. We focus on the human in this relationship, noting that humans use an amalgam of language and gesture to express themselves. Accordingly we expose the deep relationship between computer languages and continuous expression, examining how these realms may support one another, and how the artist-programmer may fully engage with both. Our argument takes us up through layers of representation, starting with symbols, then words, language and notation, to consider the role that these representations may play in human creativity. We form a cross-disciplinary perspective from psychology, computer science, linguistics, human-computer interaction, computational creativity, music technology and the arts. We develop and demonstrate the potential of this view to inform arts practice, through the practical introduction of software prototypes, artworks, programming languages and improvised performances. In particular, we introduce works which demonstrate the role of perception in symbolic semantics, embed the representation of time in programming language, include visuospatial arrangement in syntax, and embed the activity of programming in the improvisation and experience of art

Pattern Recognition

Pattern recognition is a very wide research field. It involves factors as diverse as sensors, feature extraction, pattern classification, decision fusion, applications and others. The signals processed are commonly one, two or three dimensional, the processing is done in real- time or takes hours and days, some systems look for one narrow object class, others search huge databases for entries with at least a small amount of similarity. No single person can claim expertise across the whole field, which develops rapidly, updates its paradigms and comprehends several philosophical approaches. This book reflects this diversity by presenting a selection of recent developments within the area of pattern recognition and related fields. It covers theoretical advances in classification and feature extraction as well as application-oriented works. Authors of these 25 works present and advocate recent achievements of their research related to the field of pattern recognition

Drawing Futures

Drawing Futures brings together international designers and artists for speculations in contemporary drawing for art and architecture. Despite numerous developments in technological manufacture and computational design that provide new grounds for designers, the act of drawing still plays a central role as a vehicle for speculation. There is a rich and long history of drawing tied to innovations in technology as well as to revolutions in our philosophical understanding of the world. In reflection of a society now underpinned by computational networks and interfaces allowing hitherto unprecedented views of the world, the changing status of the drawing and its representation as a political act demands a platform for reflection and innovation. Drawing Futures will present a compendium of projects, writings and interviews that critically reassess the act of drawing and where its future may lie. Drawing Futures focuses on the discussion of how the field of drawing may expand synchronously alongside technological and computational developments. The book coincides with an international conference of the same name, taking place at The Bartlett School of Architecture, UCL, in November 2016. Bringing together practitioners from many creative fields, the book discusses how drawing is changing in relation to new technologies for the production and dissemination of ideas