Thesis (M.S.)--Massachusetts Institute of Technology, Program in Media Arts & Sciences, 1998. / Includes bibliographical references (leaves 57-59). / Scott Brenner Brave. / M.S.

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2010. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 46-47). / Stage performances present many challenges and opportunities in the field of robotics. Onstage robots not only have to function flawlessly, they must interact convincingly with their human counterparts and adhere to a rigid timeline. The scope of this work is to create set pieces that look and behave like organic entities for the production of Tod Machover's new opera, Death and the Powers. With a set of design rules and techniques, I have developed the mechanical and control systems, including their interactive behavior, for several performance-ready robots. A six-legged walking robot and transformable robot were first built to verify the adopted design methodology prior to the prototyping of onstage robots. In addition, the robots were certified as performance-ready according to four criteria: the visual appearance, the overall functionality, the quality of movement, and the fluency of human-robot interaction. Two robots were successfully built and tested for use in the opera of Death and the Powers. / by Wei Dong. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2002. / Includes bibliographical references (leaves 87-94). / As means of improving the ability of the computer to respond in a way that facilitates a productive and enjoyable learning experience, this thesis proposes a system for the automated recognition and dynamical analysis of natural occurring postures when a child is working in a learning-computer situation. Specifically, an experiment was conducted with 10 children between 8 and 11 years old to elicit natural occurring behaviors during a learning-computer task. Two studies were carried out; the first study reveals that 9 natural occurring postures are frequently repeated during the children's experiment; the second one shows that three teachers could reliably recognize 5 affective states (high interest, interest, low interest, taking a break and boredom). Hence, a static posture recognition system that distinguishes the set of 9 postures was built. This system senses the postures using two matrices of pressure sensors mounted on the seat and back of a chair. The matrices capture the pressure body distribution of a person sitting on the chair. Using Gaussian Mixtures and feed-forward Neural Network algorithms, the system classifies the postures in real time. It achieves an overall accuracy of 87.6% when it is tested with children's postures that were not included in the training set. Also, the children's posture sequences were dynamically analyzed using a Hidden Markov Model for representing each of the 5 affective states found by the teachers. As a result, only the affective states of high interest, low interest, and taking a break were recognized with an overall accuracy of 87% when tested with new postures sequences coming from children included in the training set. In contrast, when the system was tested with posture sequences coming from two subjects that were not included in the training set, it had an overall accuracy of 76%. / by Selene Atenea Mota Toledo. / S.M.

Thesis (M.S.)--Massachusetts Institute of Technology, Program in Media Arts & Sciences, 1993. / Includes bibliographical references (leaves 114-118). / by Alan Greg Turransky. / M.S.

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2004. / Includes bibliographical references (p. 63-64). / The Nanogate is a micro electro mechanical systems (MEMS) device that uses a cantilever structure to control the separation between two extremely flat surfaces. It has been proposed that the Nanogate be used as part of a nanoscale instrument for studying the behavior of fluids at the molecular scale. This thesis describes the development of an integrated capacitive displacement sensor which enables nanometer precision measurement of the separation of the surfaces of the Nanogate. The work in this thesis can be divided into two parts: fabrication of a new version of the Nanogate and the development of electronics for the capacitive sensor. The fabrication part involved redesigning the Nanogate package and fabrication process to integrate the capacitive sensing electrodes, as well as to improve the process yield. The development of capacitive sensing electronics for the Nanogate involved the design of an analog front-end to convert capacitance to voltage and a custom high precision data acquisition system to digitize the output. The measured capacitance is converted back to absolute displacement by calibration with a Michelson interferometer-based displacement sensor. The results show a resolution better than 0.1 nm and the long term drift error is less than 1 nm. / by Hongshen Ma. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2000. / Includes bibliographical references (p. 79-81). / The act of sharing stories, which often characterizes the interactions between grandparents and grandchildren, exerts a profound influence on both the child listener and the grandparent teller. Unfortunately, opportunities for such sharing are rare for the many extended families who are geographically separated, and the stories go untold. Simple methods such as tape recorders or memory books can be difficult to work with, as they do not provide the powerful feedback that an active and interested listener can give. Computer-based systems have the potential to model this feedback, but in order to be effective at evoking stories, the interface must move away from keyboard and monitor and must be grounded in an understanding of conversation. This work argues that an effective story-eliciting system for grandparents must be based on a model of conversational behavior, must provide a comfortable and story-evoking environment, and that the ideal interface is an autonomous animated character. I present GrandChair, a system which can elicit, record, index, and play back grandparents' stories within an interaction model based on face-to-face conversation, and couched in an environment designed to be comfortable and story-evoking. Tellers sit in a comfortable rocking chair and tell stories with the assistance of a conversational agent on a screen, who takes the form of a child, to help them tailor their stories to a child audience, and prompts them with stories, questions, and video clips from their previous interactions. / by Jennifer Smith. / S.M.

Thesis (Ph.D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts & Sciences, 1997. / Includes bibliographical references (p. 217-223). / by Steve Mann. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2001. / Includes bibliographical references (p. 149-154). / Modern cryptography relies on algorithmic one-way functions - numerical functions which are easy to compute but very difficult to invert. This dissertation introduces physical one-way firnctions and physical one-way hash functions as primitives for physical analogs of cryptosystems. Physical one-way functions are defined with respect to a physical probe and physical system in some unknown state. A function is called a physical one-way function if (a) there exists a deterministic physical interaction between the probe and the system which produces an output in constant time (b) inverting the function using either computational or physical means is difficult (c) simulating the physical interaction is computationally demanding and (d) the physical system is easy to make but difficult to clone. Physical one-way hash functions produce fixed-length output regardless of the size of the input. These hash functions can be obtained by sampling the output of physical one-way functions. For the system described below, it is shown that there is a strong correspondence between the properties of physical one-way hash functions and their algorithmic counterparts. In particular, it is demonstrated that they are collision-resistant and that they exhibit the avalanche effect, i.e., a small change in the physical system causes a large change in the hash value. An inexpensive prototype authentication system based on physical one-way hash functions is designed, implemented, and analyzed. / (cont.) The prototype uses a disordered three-dimensional microstructure as the underlying physical system and coherent radiation as the probe. It is shown that the output of the interaction between the physical system and the probe can be used to robustly derive a unique tamper-resistant identifier at a very low cost per bit. The explicit use of three-dimensional structures marks a departure from prior efforts. Two protocols, including a one-time pad protocol, that illustrate the utility of these hash functions are presented and potential attacks on the authentication system are considered. Finally, the concept offabrication complexity is introduced as a way of quantifying the difficulty of materially cloning physical systems with arbitrary internal states. Fabrication complexity is discussed in the context of an idealized machine - a Universal Turing Machine augmented with a fabrication head - which transforms algorithmically minimal descriptions of physical systems into the systems themselves. / by Pappu Srinivasa Ravinkanth. / Ph.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Program in Media Arts & Sciences, 1998. / Includes bibliographical references (leaves 126-128). / by Reed Kram. / M.S.

Thesis (M.S.)--Massachusetts Institute of Technology, Program in Media Arts & Sciences, 1997. / Includes bibliographical references (p. 99-102). / by Marina Umaschi Bers. / M.S.