One cannot not interact

As the digital becomes part of the underlying structure of human existence and activity (just as electricity was integrated in the infrastructure), human interaction will be less and less direct. Mediated through various interfaces, human interaction via all kinds of networks becomes increasingly an expression of the semiotic condition of the human being in the post-industrial age. Professionals dedicated to human–computer interaction (HCI, a more suitable acronym than CHI) and semioticians must realize that they would benefit mutually if they would collaborate better than they have until now. Therefore, this paper submits working hypotheses to HCI practioners and to semioticians dedicated to aspects of human interaction.     

Unexpected universality results for three classes of P systems with symport/antiport

Symport and antiport are biological ways of transporting molecules through membranesin ``collaborating' pairs; in the case of symport the two molecules pass in the same direction, in the case of antiport the two molecules pass in opposite directions. Here we first survey the results about the computing power of membrane systems (P systems) using only symport/antiport rules (hence these systems compute by communication only), then we consider a recently introduced, way of defining the result of a computation in a membrane system: looking for the trace of certain objects in their movement through membranes. Rather unexpected, in this way we get characterizations of recursively enumerable languages by means of membrane systems with symport/antiport which work with multisets of objects (note the qualitative difference between the data structure used by computations – multisets: no ordering– and the data structure of the output – strings: linear ordering). A similar remark holds true for the case of analysing P systems, which work in an automata-like manner: the sequence of certain distinguished objects taken from the environment during acomputation is the string recognized by the computation. We also survey universality results from this area, with sketched proofs. Some open problems are also formulated. This revised version was published online in June 2006 with corrections to the Cover Date.     

Concerning the knowledge domain of anticipation – awareness of early contributions in the context of defining the field

The knowledge domain of anticipation is still in the process of being defined, and is therefore subject to controversies. Science was never an endeavour of consensus but rather of debate. This additional argument to the debate integrates awareness of the early Soviet/Russian contributions to a science of anticipation. From this awareness derives the understanding of why anticipation faces opposition from established viewpoints. This article ascertains that anticipation advances a fundamental view of the living. Within this view, anticipation is always expressed in action. Short of this definitory condition, anticipation fades into the grey mass of speculative predictive methods.     

The numerical method of successive interpolations for two-point boundary value problems with deviating argument

A new numerical method for two-point boundary value problems associated to differential equations with deviating argument is obtained. The method uses the fixed point technique, the trapezoidal quadrature rule, and the cubic spline interpolation procedure. The convergence of the method is proved without smoothness conditions, the kernel function being Lipschitzian in each argument. The interpolation procedure is used only on the points where the argument is modified. A practical stopping criterion of the algorithm is obtained and the accuracy of the method is illustrated on some numerical examples of the pantograph type.     

Exact Cover with Light

We suggest a new optical solution for solving the YES/NO version of the Exact Cover problem by using the massive parallelism of light. The idea is to build an optical device which can generate all possible solutions of the problem and then to pick the correct one. In our case the device has a graph-like representation and the light is traversing it by following the routes given by the connections between nodes. The nodes are connected by arcs in a special way which lets us to generate all possible covers (exact or not) of the given set. For selecting the correct solution we assign to each item, from the set to be covered, a special integer number. These numbers will actually represent delays induced to light when it passes through arcs. The solution is represented as a subray arriving at a certain moment in the destination node. This will tell us if an exact cover does exist or not.

Solving the subset-sum problem with a light-based device

We propose an optical computational device which uses light rays for solving the subset-sum problem. The device has a graph-like representation and the light is traversing it by following the routes given by the connections between nodes. The nodes are connected by arcs in a special way which lets us to generate all possible subsets of the given set. To each arc we assign either a number from the given set or a predefined constant. When the light is passing through an arc it is delayed by the amount of time indicated by the number placed in that arc. At the destination node we will check if there is a ray whose total delay is equal to the target value of the subset sum problem (plus some constants). The proposed optical solution solves a NP-complete problem in time proportional with the target sum, but requires an exponential amount of energy.     

The relative impact of student affect on performance models in a spoken dialogue tutoring system

We hypothesize that student affect is a useful predictor of spoken dialogue system performance, relative to other parameters. We test this hypothesis in the context of our spoken dialogue tutoring system, where student learning is the primary performance metric. We first present our system and corpora, which have been annotated with several student affective states, student correctness and discourse structure. We then discuss unigram and bigram parameters derived from these annotations. The unigram parameters represent each annotation type individually, as well as system-generic features. The bigram parameters represent annotation combinations, including student state sequences and student states in the discourse structure context. We then use these parameters to build learning models. First, we build simple models based on correlations between each of our parameters and learning. Our results suggest that our affect parameters are among our most useful predictors of learning, particularly in specific discourse structure contexts. Next, we use the PARADISE framework (multiple linear regression) to build complex learning models containing only the most useful subset of parameters. Our approach is a value-added one; we perform a number of model-building experiments, both with and without including our affect parameters, and then compare the performance of the models on the training and the test sets. Our results show that when included as inputs, our affect parameters are selected as predictors in most models, and many of these models show high generalizability in testing. Our results also show that overall, the affect-included models significantly outperform the affect-excluded models.     

Focussed ion beam based fabrication of micro-electro-mechanical resonators

A simple and fast process to fabricate micro-electro-mechanical (MEM) resonators with deep sub-micron transduction gaps in thin SOI is presented. The proposed process is realized on both 350 nm and 1.5 μm thin silicon-on-insulator (SOI) substrates, evaluating the possibilities for MEMS devices on thin SOI for future co-integration with CMOS circuitry on a single chip. Through the combination of conventional UV-lithography and focused ion beam (FIB) milling the process needs only two lithography steps, achieving ∼100 nm gaps, thus ensuring an effective transduction. Different FIB parameters and etching parameters and their effect on the process are reported.     

Solving the Hamiltonian path problem with a light-based computer

In this paper we propose a special computational device which uses light rays for solving the Hamiltonian path problem on a directed graph. The device has a graph-like representation and the light is traversing it by following the routes given by the connections between nodes. In each node the rays are uniquely marked so that they can be easily identified. At the destination node we will search only for particular rays that have passed only once through each node. We show that the proposed device can solve small and medium instances of the problem in reasonable time.     

On Measuring Closed‐Loop Non‐Linearity: A Topological Approach

The focal point of this paper is to develop a measure of closed‐loop non‐linearity. In this work, the Vinnicombe metric and the Quasi‐Linear Parameter Varying representation of a non‐linear system are exploited for this purpose. It is expected that the proposed measure can serve as a decision making tool for control engineers when considering whether a linear or a non‐linear control strategy should be employed to close the loop for a non‐linear system operating in a prescribed range.