Responsive Music Interfaces for Performance

In this project we have developed reactive instruments for performance. Reactive instruments provide feedback for the performer thereby providing a more dynamic experience. This is achieved through the use of haptics and robotics. Haptics provide a feedback system to the control surface. Robotics provides a way to actuate the instruments and their control surfaces. This allows a highly coordinated “dance” between performer and the instrument. An application for this idea is presented as a linear slide interface. Reactive interfaces represent a dynamic way for music to be portrayed in performance

Dynamic privacy management in pervasive sensor networks

This paper describes the design and implementation of a dynamic privacy management system aimed at enabling tangible privacy control and feedback in a pervasive sensor network. Our work began with the development of a potentially invasive sensor network (with high resolution video, audio, and motion tracking capabilities) featuring different interactive applications that created incentive for accepting this network as an extension of people’s daily social space. A user study was then conducted to evaluate several privacy management approaches – an active badge system for both online and on-site control, on/off power switches for physically disabling the hardware, and touch screen input control. Results from a user study indicated that an active badge for on-site privacy control is the most preferable method among all provided options. We present a set of results that yield insight into the privacy/benefit tradeoff from various sensing capabilities in pervasive sensor networks and how privacy settings and user behavior relate in these environments.Things That Think Consortiu

Length-Independent Voltage Fluctuations in Small Devices

Conductance fluctuations in one-dimensional lines of length L shorter than the phase-coherence length Lφ are not universal but diverge as L-2. Using the Onsager relations and voltage additivity, we show that the voltage fluctuations are independent of the distance between voltage probes. The antisymmetric (Hall-type) contribution to the voltage fluctuations is constant for all values of L. Measurements of the voltage fluctuations and correlation function between different regions in Au and Sb lines confirm these results

Temperature Dependence of the Normal-Metal Aharonov-Bohm Effect

The amplitude of h/e periodic oscillations in the magnetoresistance of very small normal-metal (Au) rings, as well as the harmonic h/2e, have been studied as a function of temperature. The amplitudes depend on the temperature T roughly as T-1/2, as expected from the averaging of conduction channels in the absence of inelastic scattering, but may not be entirely consistent with this model. At the lowest T, the size of the fluctuations in the conductance is about ΔG∼e2/h, as predicted recently

Experiences and challenges in deploying potentially invasive sensor systems for dynamic media applications

This paper describes a series of projects that explore a set of dynamic media applications built upon a potentially invasive sensor system - the Ubiquitous Media Portal, featuring high-resolution video and audio capture with user ID/tracking capabilities that we installed throughout our facility. In addition to sensors, the portals provide a display and loudspeaker to locally display information or manifest phenomena from virtual worlds. During an eight-month long period, we implemented four different applications to explore acceptance by our buildingwide users. Our results provide insight into how different levels of information presentation and perceived user control can influence the user acceptance and engagement with such sensor platforms in ubiquitous deployments.Things That Think ConsortiumNokia Research Cente

Asymmetry in the Magnetoconductance of Metal Wires and Loops

Universal conductance fluctuations in wires and Aharonov-Bohm oscillations in loops are not symmetric about H=0. The observation of asymmetry in the periodic oscillations is possible when the phase-coherence length of the wave function is comparable to the separation of the voltage probes. In both cases, four-probe measurements yield resistances which depend on lead configuration. The asymmetries appear like Hall voltages, and are consistent with Onsager\u27s relations

Direct Observation of Ensemble Averaging of the Aharonov-Bohm Effect in Normal-Metal Loops

Aharonov-Bohm magnetoconductance oscillations have been measured in series arrays of 1, 3, 10, and 30 submicron-diameter Ag loops. At constant temperature, the amplitude of the h/e oscillations is observed to decrease as the square root of number of loops, while the amplitude of h/2e conductance oscillations, measured in the same samples, is independent of the number of series loops. This is direct confirmation of the ensemble averaging properties of h/e oscillations in multiloop systems. The amplitude of the h/e oscillations is in good agreement with recent calculations

Magnetoresistance of Small, Quasi-One-Dimensional, Normal-Metal Rings and Lines

The magnetoresistance of sub-0.4-μm-diam Au and Au60Pd40 rings was measured in a perpendicular magnetic field at temperatures as low as 5 mK in search of simple, periodic resistance oscillations that would be evidence of flux quantization in normal-metal rings. However, instead of simple oscillations, a very complex structure developed in the magnetoresistance at low temperatures. Fourier analysis of all the data did not reveal convincing evidence for flux quantization in the rings. Complex structure similar to that observed in the rings was also found in the magnetoresistance of short, narrow, Au and Au60Pd40 lines. This structure appears to be associated with the small size of the devices

Intrinsic surface depression of the order parameter under mixed (s+id)-wave pair symmetry and its effect on the critical current of high-Tc SIS Josephson junctions

An intrinsic gap depression at the Superconductor-Insulator interface due to the very short value of the coherence length in High-Tc Superconductors [HTSs] is considered, in the framework of a mixed (s+id)-wave pair symmetry for the order parameter ranging from pure s to pure d-wave. This gap depression acts as the main physical agent causing the relevant reduction of IcRn(T) values with respect to BCS expectations in HTS SIS Josephson junctions. Good agreement with various experimental data is obtained with both pure s-wave and pure d-wave symmetries of the order parameter, but with amounts of gap depression depending on the pair symmetry adopted. Regardless of the pair symmetry considered, these results prove the importance of the surface order-parameter depression in the correct interpretation of the Ic(T)Rn(T) data in HTS SIS junctions. In a case of planar YBCO-based junction the use of the de Gennes condition allowed us to tentatively obtain an upper limit for the amount of d-wave present in the order parameter of YBCO.Comment: 11 pages REVTeX file, 6 PostScript figures, to be published in J. Superconductivit

Observation of h/e Aharonov-Bohm Oscillations in Normal-Metal Rings

Magnetoresistance oscillations periodic with respect to the flux h/e have been observed in submicron-diameter Au rings, along with weaker h/2e oscillations. The h/e oscillations persist to very large magnetic fields. The background structure in the magnetoresistance was not symmetric about zero field. The temperature dependence of both the amplitude of the oscillations and the background are consistent with the recent theory by Stone