Sframe: An Efficient System for Detailed DC Simulation of Bipolar Analog Integrated Circuits Using Continuation Methods

In this paper we describe an experimental system called sframe which is being incorporated into the design for manufacturability initiative at the Reading Works of AT&T Bell Laboratories. Our system is able to perform detailed and accurate DC analyses of integrated circuits containing several hundred transistors to be fabricated in a relatively complex junction isolated complementary technology

Exploring how tangible tools enable collaboration in a multi-touch tabletop game

Digital tabletop surfaces afford multiple user interaction and collaboration. Hybrid tabletops that include both tangible and multi-touch elements are increasingly being deployed in public settings (e.g. Microsoft Surface, reacTable). Designers need to understand how the different characteristics of tangible and multi-touch interface elements affect collaborative activity on tabletops. In this paper, we report on a mixed methods exploratory study of a collaborative tabletop game about sustainable development. We explore the effects of tangible and multi-touch tools on collaborative activity. Forty-five participants, in trios, played the game using both versions of the tools. Our analysis includes quantitative performance measures, qualitative themes and behavioral measures. Findings suggest that both tangible and multi-touch tools enabled effective tool use and that collaborative activity was more influenced by group dynamics than tool modality. However, we observed that the physicality of the tangible tools facilitated individual ownership and announcement of tool use, which in turn supported group and tool awareness

Let’s jam the reactable: peer learning during musical improvisation with a tabletop tangible interface

There has been little research on how interactions with tabletop and Tangible User Interfaces (TUIs) by groups of users change over time. In this article, we investigate the challenges and opportunities of a tabletop tangible interface based on constructive building blocks. We describe a long-term lab study of groups of expert musicians improvising with the Reactable, a commercial tabletop TUI for music performance. We examine interaction, focusing on interface, tangible, musical, and social phenomena. Our findings reveal a practice-based learning between peers in situated contexts, and new forms of participation, all of which is facilitated by the Reactable's tangible interface, if compared to traditional musical ensembles. We summarise our findings as a set of design considerations and conclude that construction processes on interactive tabletops support learning by doing and peer learning, which can inform constructivist approaches to learning with technology

Computational Divided Differencing and Divided-Difference Arithmetics

Tools for computational differentiation transform a program that computes a numerical function F(x) into a related program that computes F′(x) (the derivative of F). This paper describes how techniques similar to those used in computational-differentiation tools can be used to implement other program transformations—in particular, avariety of transformations for computational divided differencing. Wediscuss how computational divided-differencing techniques could lead to faster and more robust programs in scientific and graphics applications. We also describe how these ideas relate to the numerical-finite-differencing techniques that motivated Robert Paige’s work on finite differencing of set-valued expressions in SETL programs. Dedicated to the memory of Robert Paige, 1947-1999. 1