Connectionist Theory Refinement: Genetically Searching the Space of Network Topologies

An algorithm that learns from a set of examples should ideally be able to exploit the available resources of (a) abundant computing power and (b) domain-specific knowledge to improve its ability to generalize. Connectionist theory-refinement systems, which use background knowledge to select a neural network's topology and initial weights, have proven to be effective at exploiting domain-specific knowledge; however, most do not exploit available computing power. This weakness occurs because they lack the ability to refine the topology of the neural networks they produce, thereby limiting generalization, especially when given impoverished domain theories. We present the REGENT algorithm which uses (a) domain-specific knowledge to help create an initial population of knowledge-based neural networks and (b) genetic operators of crossover and mutation (specifically designed for knowledge-based networks) to continually search for better network topologies. Experiments on three real-world domains indicate that our new algorithm is able to significantly increase generalization compared to a standard connectionist theory-refinement system, as well as our previous algorithm for growing knowledge-based networks.Comment: See http://www.jair.org/ for any accompanying file

The Song in the Tower of Academia

This essay discusses the emergence of the song and the album as significant modern genres. It also follows my experiences of writing and playing songs while seeking to combine critical theory, personal essay, song-writing, music production, and on-line publishing. I have been working toward a form of writing that theorist Walter Benjamin calls “montage practice.” My work is similar to hyper-text prose, and combines recorded original songs with prose writing, photography, and video clips to make an illustrated poetry/ music/ essay form that expands our traditional understanding of genre to include the song and its amplification through the internet. Advances in computer technology and internet accessibility make this possible. My ongoing project has grown in collaboration with a group of musicians, The Karma Refugees, who get together to write and record songs. It has developed into a website where my study of poetry, personal essay, critical theory, and cultural theory meet. This article will include recorded music performance and visual montage

The influence of distraction on speech processing: How selective is selective attention?

-* indicates shared first authorship - The present study investigated the effects of selective attention on the processing of morphosyntactic errors in unattended parts of speech. Two groups of German native (L1) speakers participated in the present study. Participants listened to sentences in which irregular verbs were manipulated in three different conditions (correct, incorrect but attested ablaut pattern, incorrect and crosslinguistically unattested ablaut pattern). In order to track fast dynamic neural reactions to the stimuli, electroencephalography was used. After each sentence, participants in Experiment 1 performed a semantic judgement task, which deliberately distracted the participants from the syntactic manipulations and directed their attention to the semantic content of the sentence. In Experiment 2, participants carried out a syntactic judgement task, which put their attention on the critical stimuli. The use of two different attentional tasks allowed for investigating the impact of selective attention on speech processing and whether morphosyntactic processing steps are performed automatically. In Experiment 2, the incorrect attested condition elicited a larger N400 component compared to the correct condition, whereas in Experiment 1 no differences between conditions were found. These results suggest that the processing of morphosyntactic violations in irregular verbs is not entirely automatic but seems to be strongly affected by selective attention

Extraction from NP, frequency, and minimalist gradient harmonic grammar

Extraction of a PP from an NP in German is possible only if the headnoun and the governing verb together form a natural predicate. We show that thiscorresponds to collocational frequency of the verb-noun combinations incorpora, based on the metric of ΔP. From this we conclude that frequency shouldbe conceived of as a language-external grammatical building block that candirectly interact with language-internal grammatical building blocks (like trig-gers for movement and economy constraints blocking movement) in excitatoryand inhibitory ways. Integrating frequency directly into the syntax is not anoption in most current grammatical theories. However, things are different inGradient Harmonic Grammar, a version of Optimality Theory where linguistic objectsof various kinds can be assigned strength in the form of numerical values (weights).We show that by combining a Minimalist approach to syntactic derivations with aGradient Harmonic Grammar approach of constraint evaluation, the role of fre-quency in licensing extraction from PP in German can be integrated straightfor-wardly, the only additional prerequisite being that (verb-noun) dependencies qualifyas linguistic objects that can be assigned strength (based on their frequency)

Limb imaging of the Venus O2 visible nightglow with the Venus Monitoring Camera

We investigated the Venus O2 visible nightglow with imagery from the Venus Monitoring Camera on Venus Express. Drawing from data collected between April 2007 and January 2011, we study the global distribution of this emission, discovered in the late 70s by the Venera 9 and 10 missions. The inferred limb-viewing intensities are on the order of 150 kiloRayleighs at the lower latitudes and seem to drop somewhat towards the poles. The emission is generally stable, although there are episodes when the intensities rise up to 500 kR. We compare a set of Venus Monitoring Camera observations with coincident measurements of the O2 nightglow at 1.27 {\mu}m made with the Visible and Infrared Thermal Imaging Spectrometer, also on Venus Express. From the evidence gathered in this and past works, we suggest a direct correlation between the instantaneous emissions from the two O2 nightglow systems. Possible implications regarding the uncertain origin of the atomic oxygen green line at 557.7 nm are noted.Comment: 7 pages, 3 figure

Signatures of Interchange Reconnection: STEREO, ACE and Hinode Observations Combined

Combining STEREO, ACE and Hinode observations has presented an opportunity to follow a filament eruption and coronal mass ejection (CME) on the 17th of October 2007 from an active region (AR) inside a coronal hole (CH) into the heliosphere. This particular combination of `open' and closed magnetic topologies provides an ideal scenario for interchange reconnection to take place. With Hinode and STEREO data we were able to identify the emergence time and type of structure seen in the in-situ data four days later. On the 21st, ACE observed in-situ the passage of an ICME with `open' magnetic topology. The magnetic field configuration of the source, a mature AR located inside an equatorial CH, has important implications for the solar and interplanetary signatures of the eruption. We interpret the formation of an `anemone' structure of the erupting AR and the passage in-situ of the ICME being disconnected at one leg, as manifested by uni-directional suprathermal electron flux in the ICME, to be a direct result of interchange reconnection between closed loops of the CME originating from the AR and `open' field lines of the surrounding CH.Comment: 13 pages, 13 figures, accepted Annales Geophysica