Monte Carlo algorithm for the evaluation of the distance estimation variance in RSS-based visible light positioning

In this work, the Monte Carlo algorithm to determine the variance on the distance estimation in Received Signal Strength-based visible light positioning is considered. The method is build on the maximization of the signal-to-noise-ratio by means of matched filtering, and leads to a number of characteristics that are typically only obtained after intensive analytical elaborations. It is shown that the results match those obtained by calculating the Cramer-Rao lower bound when only the noise is considered as non-deterministic. It is demonstrated that the method is also applicable when multiple physical parameters exhibit a probability distribution, leading to an assessment of the distance estimation accuracy in more realistic settings

Drie versies van Celan: Bernlef, Kuijper en Theunynck

This article offers an interpretation of three poems that in their title refer to Paul Celan. This evokes a theoretical reflection on the question who is responsible for the intertextuality: the author, the text or the reader. With Eco’s notion of the intentio operis it is argued that the text itself contains signals that legitimize an intertextual reading. Then, with Riffaterre, the question is answered how to discover less explicit references and architexts. In the analysis of the poems of J. Bernlef, Jan Kuijper and Peter Theunynck I will indicate which verses of Celan they are referring to and how these verses function in the new text. In addition to this it is investigated how these poems fit into the poetics of their authors. Finally the different images of Celan that these poems create are discussed. In the conclusion I will come back to the theoretical starting point of the article to determine the role of the reader in the intertextual reading

Dikke boeken gedichten

Het clichébeeld wil dat gedichten verschijnen in dunne, dure boekjes met vooral erg veel wit en bijzonder weinig tekst. Daar staat paradoxaal genoeg de idee tegenover dat je voor een dichtbundel minstens even veel tijd moet uittrekken als voor een roman, misschien wel meer. Wie beide gemeenplaatsen samenneemt, moet wel tot de conclusie komen die ook Du Perron al trok: 'De Poëzie blijft, naakt en ongekromd,/een Tijdverdrijf voor enkle Fijne Luiden.' Poëzie als elitaire bezigheid voor literaire fijnproevers met te veel tijd en te veel geld dus. Afgelopen jaar verschenen er echter heel wat poëziepublicaties die dit beeld ontkrachten

High precision hybrid RF and ultrasonic chirp-based ranging for low-power IoT nodes

Hybrid acoustic-RF systems offer excellent ranging accuracy, yet they typically come at a power consumption that is too high to meet the energy constraints of mobile IoT nodes. We combine pulse compression and synchronized wake-ups to achieve a ranging solution that limits the active time of the nodes to 1 ms. Hence, an ultra low-power consumption of 9.015 µW for a single measurement is achieved. The operation time is estimated on 8.5 years on a CR2032 coin cell battery at a 1 Hz update rate, which is over 250 times larger than state-of-the-art RF-based positioning systems. Measurements based on a proof-of-concept hardware platform show median distance error values below 10 cm. Both simulations and measurements demonstrate that the accuracy is reduced at low signal-to-noise ratios and when reflections occur. We introduce three methods that enhance the distance measurements at a low extra processing power cost. Hence, we validate in realistic environments that the centimeter accuracy can be obtained within the energy budget of mobile devices and IoT nodes. The proposed hybrid signal ranging system can be extended to perform accurate, low-power indoor positioning