Low-fi skin vision: A case study in rapid prototyping a sensory substitution system

We describe the design process we have used to develop a minimal, twenty vibration motor Tactile Vision Sensory Substitution (TVSS) system which enables blind-folded subjects to successfully track and bat a rolling ball and thereby experience 'skin vision'. We have employed a low-fi rapid prototyping approach to build this system and argue that this methodology is particularly effective for building embedded interactive systems. We support this argument in two ways. First, by drawing on theoretical insights from robotics, a discipline that also has to deal with the challenge of building complex embedded systems that interact with their environments; second, by using the development of our TVSS as a case study: describing the series of prototypes that led to our successful design and highlighting what we learnt at each stage

Near field scanning luminescence and photothermal microscopy

A near field optical scanning probe microscope with force regulation is presented. The microscope force regulation uses a differential interferometer for monitoring the tip frequency while the tip provides a sub-wavelength aperture providing a system which simultaneously records topographical information (by the force microscope) and an optical image. The flexibility of the system is evident in the specific applications pursued in this research. Simultaneous force and luminescence images derived from the investigation of porous silicon are presented. We observed variation in luminescence over sub-micron distances. Furthermore, variation in the spectral distribution of small particles of porous silicon was also observed. Both these results support the quantum wire theory proposed to explain the luminescence properties of the porous silicon and its formation. The same system was slightly reconfigured to provide imaging of thermal properties of microcircuitry. The imaging was performed by detecting changes in reflectivity as a function of temperature. The first near field photothermal probe microscope is demostrated along with a simultaneous scanning force microscope. The system shows high resolution of thermal signal, but needs some noise reduction techniques to improve image quality

Input and Output Speed Components of Learning-to-Learn

Input and output speed were investigated to determine if they were components of learning-to-learn. The major criterion used to distinguish learning-to-learn from warm-up has generally (e.g. Hamilton, 1950) been the temporal persistence of learning-to-learn phenomena. Sixteen paired-associate practice lists consisting of high frequency words were presented for two trials to four acquisition groups in two sessions a day apart. Each acquisition group received input at either a fast (2 sec.) or slow (5 sec.) rate. Input speed (i.e., study interval) was the time the stimulus-response unit appeared. Subjects were required to respond to a light occurring at either a fast (.8 sec. after the onset of anticipation interval), or slow (3 sec. after onset of anticipation interval) rate. The third day each of the four acquisition groups was divided into fourths with one group being changed to the conditions received by each of the other groups and one group continuing under acquisition conditions. Acquisition data were consistent in showing reliable learning-to-learn in each of the four groups. On the Day 3 transfer task, the data showed that changing input speed and/or output speed resulted in a reliable decrement in learning. The decrement occurred regardless of whether the Day 3 speed was faster or slower than the practiced speed. These results supported the hypotheses that both speed parameters are components of learning-to-learn. The findings were discussed in terms of their relationship to micromolar theory. It was contended that general habits with respect to input and output speeds were developed such that learning new material was best if the practiced habits were appropriate. Changing the speed parameter(s) effectively required the subject to learn quantitatively different speed response(s). It was suggested that changing the speed components disrupted learned pacing behavior. Data from an analysis of overt errors occurring in transfer were used to support this explanation

OMV man/system simulation integration: A preliminary analysis and recommendation

The Orbital Maneuvering Vehicle (OMV) presents a series of challenges to the human operator. Some are unique to the OMV system itself, and are largely due to remote control versus control from the cockpit. Other challenges are not necessarily unique to the OMV, but are characteristic of many man-machine space flight systems. All of these challenges affect the operator's ability to perform his portion of the mission, and could lead to human error which might jeopardize the vehicle, mission, or both. It is imperative to make every effort to design the control and displays to facilitate the operator's task. The experimental program should address the perceptual, mediational, and motor dimensions of operator performance. With this in mind, a literature review with relevant design considerations was initiated, and a comprehensive outline of control/display parameters were developed. Out of this, a series of questions not answered in the literature was derived which can be converted into experimental protocols for the simulation program. A major task of the aircraft pilot as well as the OMV operator is prediction. Certain display principles have proved to enhance the pilot's ability to predict. A brief examination of some of these principles in relationship to OMV may be useful

Identifying the Effects of Monetary Policy Shocks on Exchange Rates Using High Frequency Data

This paper proposes a new approach to identifying the effects of monetary policy shocks in an international vector autoregression. Using high-frequency data on the prices of Fed Funds futures contracts, we measure the impact of the surprise component of the FOMC-day Federal Reserve policy decision on financial variables, such as the exchange rate and the foreign interest rate. We show how this information can be used to achieve identification without having to make the usual strong assumption of a recursive ordering.

Identifying the effects of monetary policy shocks on exchange rates using high frequency data

This paper proposes a new approach to identifying the effects of monetary policy shocks in an international vector autoregression. Using high-frequency data on the prices of eurodollar contracts, we measure the impact of the surprise component of the FOMC-day Federal Reserve policy decision on financial variables, such as the exchange rate and the foreign interest rate. We show how this information can be used to achieve identification without having to make the usual strong assumption of a recursive ordering. JEL Classification: C32, E52, F30Exchange Rates, High Frequency Data, Identification, monetary policy, Vector autoregression