In this letter, we study the trade-off between exploration and exploitation for linear quadratic adaptive control. This trade-off can be expressed as a function of the exploration and exploitation costs, called cumulative regret. It has been shown over the years that the optimal asymptotic rate of the cumulative regret is in many instances $\mathcal {O}(\sqrt {T})$ . In particular, this rate can be obtained by adding a white noise external excitation, with a variance decaying as $\mathcal {O}(1/\sqrt {T})$ . As the amount of excitation is pre-determined, such approaches can be viewed as open loop control of the external excitation. In this contribution, we approach the problem of designing the external excitation from a feedback perspective leveraging the well known benefits of feedback control for decreasing sensitivity to external disturbances and system-model mismatch, as compared to open loop strategies. We base the feedback on the Fisher information matrix which is a measure of the accuracy of the model. Specifically, the amplitude of the exploration signal is seen as the control input while the minimum eigenvalue of the Fisher matrix is the variable to be controlled. We call such exploration strategies Fisher Feedback Exploration (F2E). We propose one explicit F2E design, called Inverse Fisher Feedback Exploration (IF2E), and argue that this design guarantees the optimal asymptotic rate for the cumulative regret. We provide theoretical support for IF2E and in a numerical example we illustrate benefits of IF2E and compare it with the open loop approach as well as a method based on Thompson sampling.
Cyborg insects are a major part of the vision of future interactions of the living world and technology, including but not limited to the Internet of Living Things (IoLT). They are crawling or flying insects with additional electronic circuitry allowing remote control of their movement and collection of sensory data. In this critical review, we survey the historical development of cyborg insects engineering, from the first backpacks on insects used for communication and sensing, to different methods of control and actuation of insects’ locomotion. We review the suggested applications of cyborg insects ranging from military use to agriculture, pointing out the problematic connotations of swarms and cyborgs in these contexts. We address the applications and the narratives around engineered insects from the perspective of philosophy, economy, law, and politics. We add perspectives on emancipatory potential of cyborg technology and where the future of it could lie.
This paper aims at providing a framework suitable for justification of classical convolution integral and Fourier transform in many cases not covered by the usual definition of integral used for signal theory applications. Generalized functions approach from functional analysis is used, simplifying it to be approachable for engineers while retaining the rigor. The generalized functions approach results in an elegant and applicable definition of integral known before in the mathematical literature which is readily applicable in signal theory, justifying formulae usually seen as dubious and criticised for lack of rigor. The study offers a rigorous, simple and understandable definition of integral for use in analog signal theory, helping the formalization of engineering education by means of rigor. Main advantage of this approach is retaining the classical notation used in signal theory as well as its straightforward justification of key formulae in signal theory resulting from convolution and/or Fourier transform.
In this paper we examine the representations of quantum theory and technology in visual media. Namely, we conduct a thorough content analysis of film scripts in science fiction and fantasy to discover ways quantum physics and computing are portrayed: examples include quantum computer scepticism, quantum as proxy for complexity/intelligence, and quantum theory as a vehicle for mysticism. We proceed with motif analysis in quantum theory and technology illustrations in outlets representative of modern global north economy, news, and science writing. There we extract the dominant symbols of quantum discourse and compare them to quantum technology imaginaries in literature. We recognise the repeated and replicated bias towards quantum technology as fuzzy, nonbinary, subjective, mystical, as well as a venue of a new arms/space race.
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