Working with Nonstandard Models
Most of the research in foundations of mathematics that I do in some way or another involves the use of nonstandard models. I will give a few examples, and indicate what is involved.
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OF THE DISSERTATION Relational Models for Human-Object Interactions and Object Affordances By Chaitanya Desai Doctor of Philosophy in Computer Science University of California, Irvine, 2013 Professor Deva Ramanan, Chair Humans have the remarkable ability to look at an image and decipher a wealth of information about the scene it depicts. In particular, humans are very good at the following: 1) Locating various objects in the scene and telling how they are oriented, and 2) Understanding the different activities that the people in the scene are engaged in. In this thesis, we tackle the problem of helping a vision system achieve these two goals. Our techniques build on the observation that human activities, their poses and the nature of their interaction with objects in their environment are all dependent on each other. The thesis proposes techniques to model such dependencies and learns the nature of person-object interactions from training examples. While previous approaches typically deal with problems of object-detection, human-body pose estimation and activity recognition as isolated problems, the thesis proposes a framework that jointly addresses them. We show superior empirical performance to state-of-the-art techniques designed for each of the three tasks. A 2D pictorial structure framework is at the core of our approach. By handling appearance changes due to viewpoint, 3D pose and occlusions in a principled fashion, we show that such models can be quite powerful and versatile.
The Inca Occupation of the South Coast of Peru
like the others, however; it forks into several nearly parallel ravines of which the largest are Huayuri, Rio Grande-Palpa, Ingenio (called Collao in ancient times), Nasca proper (the ancient Caxamarca), Taruga, and Poroma. Due to peculiarities of the local topography, the irrigated areas in Ica and the ravines of Nasca are located inland, at the foot of the mountains, rather than at the mouths of the rivers as is more usual in Peruvian coastal valleys. No sharp natural or cultural boundary separates the valley of Chincha from the valleys of Cafiete (ancient Huarco and Runahuana), Asia, and Mala, the next valleys going up the coast to the northwest. At the other end of the area we are considering, however, there is a sharp break; beyond Yauca the Andean foothills reach out to the sea, natural conditions are quite different, and there are important differences in the archaeological picture as well. The historical sources which mention the south coast are not particularly helpful, except in so far as they provide us with a few dates. To begin with, no chronicler gives an explicit account of the political organization of the south coast at the time it came into contact with the Incas. It can, perhaps, be inferred from Cabello Balboa's statements about common policy toward the Inca invaders that there was some sort of political connection between the valleys of Mala, Cafiete, and Chincha, but the connection need have been no more than a temporary military alliance. Cabello makes no mention at all of Pisco. The valleys of Ica, Nasca, and 125