A survey on mouth modeling and analysis for Sign Language recognition

© 2015 IEEE.Around 70 million Deaf worldwide use Sign Languages (SLs) as their native languages. At the same time, they have limited reading/writing skills in the spoken language. This puts them at a severe disadvantage in many contexts, including education, work, usage of computers and the Internet. Automatic Sign Language Recognition (ASLR) can support the Deaf in many ways, e.g. by enabling the development of systems for Human-Computer Interaction in SL and translation between sign and spoken language. Research in ASLR usually revolves around automatic understanding of manual signs. Recently, ASLR research community has started to appreciate the importance of non-manuals, since they are related to the lexical meaning of a sign, the syntax and the prosody. Nonmanuals include body and head pose, movement of the eyebrows and the eyes, as well as blinks and squints. Arguably, the mouth is one of the most involved parts of the face in non-manuals. Mouth actions related to ASLR can be either mouthings, i.e. visual syllables with the mouth while signing, or non-verbal mouth gestures. Both are very important in ASLR. In this paper, we present the first survey on mouth non-manuals in ASLR. We start by showing why mouth motion is important in SL and the relevant techniques that exist within ASLR. Since limited research has been conducted regarding automatic analysis of mouth motion in the context of ALSR, we proceed by surveying relevant techniques from the areas of automatic mouth expression and visual speech recognition which can be applied to the task. Finally, we conclude by presenting the challenges and potentials of automatic analysis of mouth motion in the context of ASLR

A Comprehensive Performance Evaluation of Deformable Face Tracking "In-the-Wild"

Recently, technologies such as face detection, facial landmark localisation and face recognition and verification have matured enough to provide effective and efficient solutions for imagery captured under arbitrary conditions (referred to as "in-the-wild"). This is partially attributed to the fact that comprehensive "in-the-wild" benchmarks have been developed for face detection, landmark localisation and recognition/verification. A very important technology that has not been thoroughly evaluated yet is deformable face tracking "in-the-wild". Until now, the performance has mainly been assessed qualitatively by visually assessing the result of a deformable face tracking technology on short videos. In this paper, we perform the first, to the best of our knowledge, thorough evaluation of state-of-the-art deformable face tracking pipelines using the recently introduced 300VW benchmark. We evaluate many different architectures focusing mainly on the task of on-line deformable face tracking. In particular, we compare the following general strategies: (a) generic face detection plus generic facial landmark localisation, (b) generic model free tracking plus generic facial landmark localisation, as well as (c) hybrid approaches using state-of-the-art face detection, model free tracking and facial landmark localisation technologies. Our evaluation reveals future avenues for further research on the topic.Comment: E. Antonakos and P. Snape contributed equally and have joint second authorshi

Recent Advances in Predicting Earthquake-Induced Sliding Displacements of Slopes

This paper summarizes recent research related to predicting earthquake-induced sliding displacements of earth slopes. Recently developed empirical models for the prediction of sliding displacements for shallow (rigid) failure surfaces are discussed, and comparisons of the different models demonstrate that including peak ground velocity, along with peak ground acceleration, reduces the median displacement prediction and the standard deviation of the prediction. Thus, peak velocity provides important information regarding the level of sliding displacement. A framework is developed such that the recently developed empirical displacement models for rigid sliding can be used for deeper, flexible failure surfaces, where the dynamic response of the sliding mass is important. This framework includes predicting the seismic loading for the sliding mass in terms of the maximum seismic coefficient (kmax) and the maximum velocity of the seismic coefficient-time history (k-velmax). The predictive models for kmax and k-velmax are a function of the peak ground acceleration (PGA), peak ground velocity (PGV), the natural period of the sliding mass (Ts), and the mean period of the earthquake motion (Tm). With a slight modification, the empirical predictive models for rigid sliding masses can be used, with PGA replaced by kmax and PGV replaced by k-velmax. The standard deviations for the modified predictive models for flexible sliding masses are slightly smaller than those for rigid sliding masses

Aharonov-Bohm effect as a diffusion phenomenon

This paper presents a hydrodynamical view of the Aharonov-Bohm effect, using Nelson's formulation of quantum mechanics. Our aim is to compare our results with other systems and gain a better understanding of the mysteries behind this effect, such as why the motion of a particle is affected in a region where there is no magnetic field. Some theories suggest that this effect is due to the non-local action of the magnetic field on the particle, or even the physical significance of vector potentials over magnetic fields. Our main purpose is to use Nelson's formulation to describe the effect and demonstrate that it can be explained by the direct action of the current surrounding the magnetic field region (i.e. a cylinder) on the particle outside of it. In this context, magnetic fields and vector potentials serve as tools for finding other fundamental quantities that arise from the interaction between two fields: the quantum background fields described by Nelson's quantum theory. Finally, we investigate the relationship between hidden variables and quantum fluctuations and their role in this phenomenon.Comment: 34 pages, no figure

Hydrologic balance estimation using GIS in Korinthia prefecture, Greece

The main objective of this work is to determine the parameters of hydrological balance for several basins in the prefecture of Korinthia (SE Greece), using hydrometeorological data and geographic information systems (GIS) technology. Multiple linear regression and GIS were used to estimate the spatial distribution of rainfall. The largest precipitation amounts occur in the SW part of the region and decrease towards the eastern and northern coastal parts. The long term mean annual rainfall is 1.39×10<sup>9</sup> m<sup>3</sup>. Based on the Thornthwaite method, infiltration and streamflow were estimated to be 0.29×10<sup>9</sup> m<sup>3</sup>/yr and 0.38×10<sup>9</sup> m<sup>3</sup>/yr, respectively. The unequal distribution of rainfall results in water surplus in the western part of Korinthia prefecture and water deficit in the eastern. We conclude that he estimation of hydrologic balance is a useful tool in order to establish sustainable water resources management in each hydrological basin

The Conditional Lucas & Kanade Algorithm

The Lucas & Kanade (LK) algorithm is the method of choice for efficient dense image and object alignment. The approach is efficient as it attempts to model the connection between appearance and geometric displacement through a linear relationship that assumes independence across pixel coordinates. A drawback of the approach, however, is its generative nature. Specifically, its performance is tightly coupled with how well the linear model can synthesize appearance from geometric displacement, even though the alignment task itself is associated with the inverse problem. In this paper, we present a new approach, referred to as the Conditional LK algorithm, which: (i) directly learns linear models that predict geometric displacement as a function of appearance, and (ii) employs a novel strategy for ensuring that the generative pixel independence assumption can still be taken advantage of. We demonstrate that our approach exhibits superior performance to classical generative forms of the LK algorithm. Furthermore, we demonstrate its comparable performance to state-of-the-art methods such as the Supervised Descent Method with substantially less training examples, as well as the unique ability to "swap" geometric warp functions without having to retrain from scratch. Finally, from a theoretical perspective, our approach hints at possible redundancies that exist in current state-of-the-art methods for alignment that could be leveraged in vision systems of the future.Comment: 17 pages, 11 figure

WATER RESOURCES IN THE WIDER AREA OF THE APOSELEMIS BASIN, CRETE ISLAND, GREECE

Η γνώση του υδρολογικού ισοζυγίου μιας λεκάνης αποτελεί απαραίτητη προϋπόθεση για να εκτιμηθεί η ασφαλής απόδοση των υδροφόρων συστημάτων ώστε να εξασφαλι­ σθεί η ορθολογική και βιώσιμη διαχείριση τους. Προκειμένου να αντιμετωπιστεί η διαταραχή της ισορροπίας του υδατικού ισοζυγίου στην υδρογεωλογική λεκάνη του Αποσελέμη αλλά και στον ευρύτερο χώρο του όρους Δίκτη είναι απαραίτητη η εκτίμη­ ση του υδατικού ισοζυγίου των επιμέρους λεκανών απορροής δηλαδή της λεκάνης του Αποσελέμη, των οροπεδίων Λασιθίου και Καθαρού καθώς και της υπόλοιπης επιφάνειας απορροής του όρους Δίκτη. Προς τούτο χρησιμοποιήθηκαν οι καταγραφές της απορροής του Αποσελέμη στη θέση Ποταμιές και οι μετρήσεις βροχής σε επτά βροχομετρικούς σταθμούς εντός ή πλησίον της λεκάνης απορροής του Αποσελέμη κατά την περίοδο 1967-2003. Τα όρια των περιοχών και οι μορφολογικές παράμετροι καθορί­ στηκαν με τη χρήση GIS, με βάση το ψηφιακό μοντέλο ανάγλυφου (DEM). Η πραγμα­ τική εξατμισοδιαπνοή σε όλη τη περιοχή υπολογίστηκε με τη μέθοδο ThornthwaiteMather. Διαπιστώθηκε υψηλός βαθμός συσχέτισης της απορροής του Αποσελέμη με τη βροχόπτωση στην ευρύτερη περιοχή πέρα από τα συμβατικά όρια της λεκάνης απορ­ ροής του. Σημαντικό ποσοστό της ετήσιας βροχόπτωσης και απορροής στην περιοχή τροφοδοτεί τόσο τα καρστικά υδροφόρα συστήματα κατάντη όσο και την απορροή του Αποσελέμη. Οι καρστικοί υδροφορίες εκφορτίζονται μερικώς από μεγάλες παράκτιες και υποθαλάσσιες υφάλμυρες πηγές, καθώς και από μικρότερες πηγές γλυκού νερού στην ενδοχώρα. Επιβεβαιώθηκε τέλος με ιχνηθετήσεις που εκτέλεσε το ΙΓΜΕ η υ­ δραυλική επικοινωνία του οροπεδίου Λασιθίου και των κατάντη υδροφορέων.The estimation of hydrologie balance is useful in order to assess the safe yield of the aquifer systems and therefore to establish their rational exploitation and sustainable management. Over-abstractions of groundwater in Aposelemis basin resulted in a severe disequilibrium of its water balance. In order to overcome this disequilibrium we studied the hydrological balance in the wider area ofDikti mountain which comprises the drainage basins of Aposelemis river, ofLasithi and Katharo plateaus and of the rest of the drainage area of Dikti. The data used are the monthly values of Aposelemis runoff in the gauge station at Potamies and rainfall data for the period 1967-2003 from seven stations located within or in the close vicinity of the drainage basin of Aposelemis. Using ArcView GIS, the hydrological basin of Aposelemis river and the drainage area ofDikti were delineated, based on the digital elevation model (DEM). The actual évapotranspiration was estimated by the Thornthwaite method. A high inter-relationship exists between the flow of the Aposelemis river and rainfall outside the conventional boundaries of the Aposelemis basin. A significant portion of the annual rainfall, in that wider area is not only recharging the karst systems downstream but also contributing to the flow of Aposelemis river. Karst aquifer systems are partially drained by large coastal and submarine brackish springs and by inland freshwater springs. Finally, tracer studies carried out by IGME confirmed the hydraulic connection between Lasithiplateau and downstream aquifer systems