Entrainment and musicality in the human system interface

What constitutes our human capacity to engage and be in the same frame of mind as another human? How do we come to share a sense of what ‘looks good’ and what ‘makes sense’? How do we handle differences and come to coexist with them? How do we come to feel that we understand what someone else is experiencing? How are we able to walk in silence with someone familiar and be sharing a peaceful space? All of these aspects are part of human ‘interaction’. In designing interactive technologies designers have endeavoured to explicate, analyse and simulate, our capacity for social adaptation. Their motivations are mixed and include the desires to improve efficiency, improve consumption, to connect people, to make it easier for people to work together, to improve education and learning. In these endeavours to explicate, analyse and simulate, there is a fundamental human capacity that is beyond technology and that facilitates these aspects of being, feeling and thinking with others. That capacity, we suggest, is human entrainment. This is our ability to coordinate the timing of our behaviours and rhythmically synchronise our attentional resources. Expressed within the movements of our bodies and voices, it has a quality that is akin to music. In this paper, disparate domains of research such as pragmatics, social psychology, behaviourism, cognitive science, computational linguistics, gesture, are brought together, and considered in light of the developments in interactive technology, in order to shape a conceptual framework for understanding entrainment in everyday human interaction.     

Evaluating software reuse alternatives: a model and its application to an industrial case study

We propose a model that enables software developers to systematically evaluate and compare all possible alternative reuse scenarios. The model supports the clear identification of the basic operations involved and associates a cost component with each basic operation in a focused and precise way. The model is a practical tool that assists developers to weigh and evaluate different reuse scenarios, based on accumulated organizational data, and then to decide which option to select in a given situation. The model is currently being used at six different companies for cost-benefit analysis of alternative reuse scenarios; we give a case study that illustrates how it has been used in practice.     

SlideBar: Analysis of a linear input device

The SlideBar is a physical linear input device for absolute position control of 1° of freedom, consisting of a physical slider with a graspable knob positioned near or attached to the keyboard. Its range of motion is directly mapped to a one dimensional input widget such as a scrollbar. The SlideBar provides absolute position control in one dimension, is usable in the non-dominant hand in conjunction with a pointing device, and offers constrained passive haptic feedback. These characteristics make the device appropriate for the common class of tasks characterized by one-dimensional input and constrained range of operation. An empirical study of three devices (SlideBar, mouse controlled scrollbar, and mousewheel) shows that for common scrolling tasks, the SlideBar has a significant advantage over a standard mouse controlled scrollbar in user preference. In addition, users tended to prefer it over the mousewheel (without statistical significance).     

Dynamically identifying regenerative cycles in Simulation-based Optimization Algorithms for Markov chains

Simulation-based algorithms for maximizing the average reward of a parameterized Markov chain often rely upon the existence of a state which is recurrent for all choices of parameter values. The question of which recurrent state should serve to mark the end of a regenerative cycle is a very important practical consideration in applications. Even when all of the states of the process are recurrent, some states tend to be visited more often than others, and lengthy renewal cycles tend to result in high variance estimates of the gradient. To address this difficulty, we analyze a mechanism for adjusting this special state dynamically (i/sup */-adaptation) as applied to the "batch" simulation-based optimization algorithm of a previous paper. We show that the desirable convergence properties of the original "batch" algorithm are retained with i/sup */-adaptation, namely the almost sure convergence of the parameter vector to a critical point.     

Input-output feedback linearization of time-delay systems

In this note, the input-output linearization problem (IOLP) for a class of single-input-single-output nonlinear systems with multiple delays in the input, the output, and the state is studied. The problem is solved by means of various static or dynamic compensators, including state and output feedback. The mathematical setting is based on some noncommutative algebraic tools and the introduction of a nonlinear version of the so-called Roesser models for this class of systems. These are claimed to be the cornerstones for studying nonlinear time-delay systems. Necessary and sufficient conditions are given for the existence of a static or pure shift output feedback which solves the IOLP. Sufficient conditions for the existence of a dynamic state feedback solution are included as well.     

Correct Understanding of the Helmholtz Decomposition in the Radial-Averaging Method for Describing Centrifugal Separation

The theory of separation, based on radial averaging, in a Zippe centrifuge is developed. Certain aspects of the theory of the rotational potential and the errors in understanding the essence of the Helmholtz decomposition as it applies to a gas centrifuge are elucidated. It is shown that the Helmholtz decomposition method does not have cetain drawbacks of the classical theory of the radial averaging method and makes it possible to take account of the rotational flows due to the feed, find expicitly the transit flow distribution, take account of the radial nonuniformity, and take account of the radial convective transport of an isotope by the circulation and transit flows, and the method is not limited by the assumption that the feed flow is small.     

Reliability of the Coolant Flow Rate Measuring System at the Ignalina Nuclear Power Plant

Age assessment and control of the reliability of the coolant flow-rate measurement system of the RBMK-1500 reactor at the Ignalina nuclear power plant are examined. A statistical analysis is made of the data obtained from measurements of the techanical characteristics of SHADR-32M flow meters. A mathematical model of the aging of flow meters and reliability estimates is constructed. A strategy is developed for replacing SHADR; this strategy makes it possible to support the required relaibility of the entire coolant flow-rate measurement system.