Making Good on LSTMs' Unfulfilled Promise

LSTMs promise much to financial time-series analysis, temporal and cross-sectional inference, but we find that they do not deliver in a real-world financial management task. We examine an alternative called Continual Learning (CL), a memory-augmented approach, which can provide transparent explanations, i.e. which memory did what and when. This work has implications for many financial applications including credit, time-varying fairness in decision making and more. We make three important new observations. Firstly, as well as being more explainable, time-series CL approaches outperform LSTMs as well as a simple sliding window learner using feed-forward neural networks (FFNN). Secondly, we show that CL based on a sliding window learner (FFNN) is more effective than CL based on a sequential learner (LSTM). Thirdly, we examine how real-world, time-series noise impacts several similarity approaches used in CL memory addressing. We provide these insights using an approach called Continual Learning Augmentation (CLA) tested on a complex real-world problem, emerging market equities investment decision making. CLA provides a test-bed as it can be based on different types of time-series learners, allowing testing of LSTM and FFNN learners side by side. CLA is also used to test several distance approaches used in a memory recall-gate: Euclidean distance (ED), dynamic time warping (DTW), auto-encoders (AE) and a novel hybrid approach, warp-AE. We find that ED under-performs DTW and AE but warp-AE shows the best overall performance in a real-world financial task

Sounding the body: the role of the Valsalva mechanism in the emergence of the linguistic sign

The main aim of this study, conducted within STEELS, a gestural theory of the origins of speech, is to set out a proposal as to the possible role of the Valsalva mechanism in the emergence of the linguistic sign. STEELS posits that in the earliest forms of speech developed by Homo, vocomimetic laryngeal resonances of nonlinguistic origin were integrated into LV (laryngeal + vowel) protosyllables referring back to oro-naso-laryngeal (ONL) actions such as breathing, sneezing and coughing. It further posits that these protosyllables were conceptually mapped to non-ONL bodily actions making use of the Valsalva manoeuvre, such as lifting, birthing, and defecating. This claim, which stems from a submorphemic analysis of certain Proto-Indo-European “body-part” roots projected back, within a gestural framework, to the emergence of speech, suggests that the vocomimetic protosyllables posited would have become (self-)referential through a neurocognitive process of recurrent, somatotopically-driven pattern-extraction.Le but principal de cette étude, menée dans le cadre de la TSG, théorie gestuelle des origines du langage articulé, est d’explorer les contours de l’éventuel rôle qu’a pu jouer le mécanisme de Valsalva dans l’émergence du signe linguistique. La TSG postule que dans les premières conformations du langage développées par Homo, des résonances laryngales à caractère vocomimétique d’origine non linguistique ont pu être incorporées dans des protosyllabes de type LV (laryngale + voyelle) renvoyant auto-référentiellement à des actions bucco-naso-laryngales (BNL) telles que respirer, éternuer ou tousser. Elle postule également que ces protosyllabes ont pu être projetées sur des actions corporelles autres que BNL faisant appel à la manœuvre de Valsalva, telles que soulever, enfanter ou déféquer. Cette affirmation, fondée sur une analyse submorphémique de certaines racines du proto-indo-européen renvoyant au corps, rétroprojetée dans une perspective gestuelle jusqu’à l’émergence du langage articulé, laisse penser que les protosyllabes vocomimétiques postulées seraient devenues (auto-)référentielles au moyen d’un processus neurocognitif impliquant l’extraction de schémas récurrents de traits formels somatotopiquement mu

A Non-Rigid Registration Method for Analyzing Myocardial Wall Motion for Cardiac CT Images

Cardiac resynchronization therapy (CRT) has a high percentage of non-responders. Successfully locating the optimal location for CRT lead placement on a priori images can increase efficiency in procedural preparation and execution and could potentially increase the rate of CRT responders. Registration has been used in the past to assess the motion of medical images. Specifically, one method of non-rigid registration has been utilized to assess the motion of left ventricular MR cardiac images. As CT imaging is often performed as part of resynchronization treatment planning and is a fast and accessible means of imaging, extending this registration method to assessing left ventricular motion of CT images could provide another means of reproducible contractility assessment. This thesis investigates the use of non-rigid registration to evaluate the myocardium motion in multi-phase multi-slice computed tomography (MSCT) cardiac imaging for the evaluation of mechanical contraction of the left ventricle

Introduction

This second issue of Lexis is devoted to the topic of lexical submorphemics, an emerging – and therefore still controversial – field of study whose aim is to account for elements in the lexicon of a language that form parts of morphemes, and are construed as playing a role in the construction of ‘meaning’. Its object of study is the ‘submorpheme’: its essence, structure, function, combinatorial properties, distribution, invariance and variability, as well as its links with notions, cognition,..

Préface

La revue électronique bilingue Lexis, à comité scientifique international (ISSN 1951-6215), fonctionne dans un esprit d’ouverture et de découverte. Elle publie des articles sur le lexique anglais (deux numéros thématiques par an, avec une section « comptes-rendus » d’ouvrages de nature lexicologique, et de numéros hors série, comme la publication d’actes de colloques), dans une perspective tant synchronique que diachronique. Elle dépend du Centre d’Etudes Linguistiques (CEL) de l’Université J..

Submorphemic iconicity in the lexicon: a diachronic approach to English ‘gn- words’

By applying a principle of submorphemic invariance to the word-initial segment gn- (phonologically /n/) in the heuristic class of English ‘gn- words’, I show that this segment functions as a ‘sublexical marker’ (), defined as a semiologically and notionally invariant submorphemic unit within the subset(s) of words of which it is a formative. I go on to claim, based on evidence provided by phononotional GN-/GVN(-) alternation, that although must be considered as structurally indivisible in Modern English, in may originally have functioned as a ‘core invariant’ and as a variable in the pre-history of English, specifically in Proto-Indo-European. Analysing gn- in most ‘gn- words’ of Anglo-Saxon origin and some of Greek origin as the surface trace of an underlying notional domain linked to jaw-related phenomena (sound articulation, mastication, manducation, etc.) suggests that there exists an extralinguistically motivated, causal relation between and this domain involving the concept of ‘submorphemic iconicity’.L’application d’un principe d’invariance submorphémique au segment initial gn- (phonologiquement /n/) dans la classe heuristique des ‘mots en gn-’ de l’anglais nous permet de montrer que ce segment fonctionne comme un ‘marqueur sub-lexical’ (), défini comme une unité submorphémique douée d’une invariance tant sémiologique que notionnelle au sein du sous-ensemble de mots dont il est un élément formateur. Nous émettons l’hypothèse, fondée sur l’existence d’une alternance phono-notionnelle GN-/GVN(-), que bien que semble être structurellement indivisible en anglais moderne, dans a pu fonctionner comme ‘invariant-noyau’ et comme variable à date préhistorique, et tout particulièrement en indo-européen commun. En analysant gn- dans la plupart des ‘mots en gn-’ d’origine anglo-saxonne et dans certains vocables d’origine grecque comme étant la trace en surface d’un domaine notionnel lié aux phénomènes temporomandibulaires (articulation de sons, mastication, manducation, etc.), nous sommes amené à formuler l’hypothèse qu’il existe une motivation extralinguistique, de nature causale, entre et ce domaine qui intègre le concept d’« iconicité submorphémique »

The emergence of the linguistic sign : vocomimesis, symmetry and enaction

La TSG postule que les origines du signe linguistique étaient à la fois auto-référentielles et vocomimétiques. Plus précisément, des résonances vocales accompagnant des mouvements bilatéralement symétriques de fermeture-ouverture de la mâchoire ont pu être recrutées intersubjectivement par Homo pour renvoyer à la mâchoire et sa région anatomique, puis projetées homologiquement sur des parties du corps à symétrie bilatérale disposées de part et d’autre du plan médian, ou le long de celui-ci. Nous soutenons que cette stratégie de nomination du corps, qui semble encore décelable submorphémiquement en p-i-e, implique plusieurs concepts-clés énactifs (fabrication du sens, incarnation…) et neurophysiologiques (systèmes miroirs…).  STEELS postulates that the origins of the linguistic sign were both self-referential and vocomimetic. More precisely, vocal resonances accompanying bilaterally symmetrical, close-open movements of the jaw may have been recruited intersubjectively by Homo to refer back to the jaw and its anatomical region, before being mapped homologously to bilaterally symmetrical parts of the body located to each side of the median plane, or along it. I claim that this body-naming strategy, which may still be detectable submorphemically in certain PIE body-part words, involves key enactive concepts such as sense-making and embodiment, and neurophysiological phenomena such as mirror neuron systems. STEELS postulates that the origins of the linguistic sign were both self-referential and vocomimetic. More precisely, vocal resonances accompanying bilaterally symmetrical, close-open movements of the jaw may have been unconsciously recruited by Homo to refer back to the jaw and its anatomical region, before being mapped homologously to other bilaterally symmetrical parts of the body located to each side of the median plane, or along it. I claim that this body-naming strategy, which may still be detectable submorphemically in certain Proto-Indo-European body-part words, involves key enactive concepts such as sense-making and embodiment, and neurophysiological phenomena such as mirror neuron systems