Two-Stage Orthogonal Least Squares Methods for Neural Network Construction

A number of neural networks can be formulated as the linear-in-the-parameters models. Training such networks can be transformed to a model selection problem where a compact model is selected from all the candidates using subset selection algorithms. Forward selection methods are popular fast subset selection approaches. However, they may only produce suboptimal models and can be trapped into a local minimum. More recently, a two-stage fast recursive algorithm (TSFRA) combining forward selection and backward model refinement has been proposed to improve the compactness and generalization performance of the model. This paper proposes unified two-stage orthogonal least squares methods instead of the fast recursive-based methods. In contrast to the TSFRA, this paper derives a new simplified relationship between the forward and the backward stages to avoid repetitive computations using the inherent orthogonal properties of the least squares methods. Furthermore, a new term exchanging scheme for backward model refinement is introduced to reduce computational demand. Finally, given the error reduction ratio criterion, effective and efficient forward and backward subset selection procedures are proposed. Extensive examples are presented to demonstrate the improved model compactness constructed by the proposed technique in comparison with some popular methods.

Kernel based approaches to local nonlinear non-parametric variable selection

In this paper, we consider the variable selection problem for a nonlinear non-parametric system. Two approaches are proposed, one top-down approach and one bottom-up approach. The top-down algorithm selects a variable by detecting if the corresponding partial derivative is zero or not at the point of interest. The algorithm is shown to have not only the parameter but also the set convergence. This is critical because the variable selection problem is binary, a variable is either selected or not selected. The bottom-up approach is based on the forward/backward stepwise selection which is designed to work if the data length is limited. Both approaches determine the most important variables locally and allow the unknown non-parametric nonlinear system to have different local dimensions at different points of interest. Further, two potential applications along with numerical simulations are provided to illustrate the usefulness of the proposed algorithms.

The prognostic and therapeutic value of EpHA2 in early colorectal cancer (CRC).

Background: EpHA2 is a 130 kD transmembrane glycoprotein belonging to ephrin receptor subfamily and involved in angiogenesis/tumour neovascularisation. High EpHA2 mRNA level has recently been implicated in cetuximab resistance. Previously, we found high EpHA2 levels in a panel of invasive colorectal cancer (CRC) cells, which was associated with high levels of stem-cell marker CD44. Our aim was to investigate the prognostic value of EpHA2 and subsequently correlate expression levels to known clinico-pathological variables in early stage CRC. Methods: Tissue samples from 509 CRC patients were analysed. EpHA2 expression was measured using IHC. Kaplan-Meier graphs were used. Univariate and multivariate analyses employed Cox Proportional Hazards Ratio (HR) method. A backward selection method (Akaike’s information criterion) was used to determine a refined multivariate model. Results: EpHA2 was highly expressed in CRC adenocarcinoma compared to matched normal colon tissue. In support of our preclinical invasive models, strong correlation was found between EpHA2 expression and CD44 and Lgr5 staining (p<0.001). In addition, high EpHA2 expression significantly correlated with vascular invasion (p=0.03).HR for OS for stage II/III patients with high EpHA2 expression was 1.69 (95%CI: 1.164-2.439; p=0.003). When stage II/III was broken down into individual stages, there was significant correlation between high EpHA2 expression and poor 5-years OS in stage II patients (HR: 2.18; 95%CI: 1.28-3.71; p=0.005).HR in the stage III group showed a trend to statistical significance (HR: 1.48; 95%CI=0.87-2.51; p=0.05). In both univariate and multivariate analyses of stage II patients, high EpHA2 expression was the only significant factor and was retained in the final multivariate model. Higher levels of EpHA2 were noted in our RAS and BRAF mutant CRC cells, and silencing EpHA2 resulted in significant decreases in migration/invasion in parental and invasive CRC sublines. Correlation between KRAS/NRAS/BRAFmutational status and EpHA2 expression in clinical samples is ongoing. Conclusions: Taken together, our study is the first to indicate that EpHA2 expression is a predictor of poor clinical outcome and a potential novel target in early stage CRC.

On the Privacy of Encrypted Skype Communications

The privacy of voice over IP (VoIP) systems is achieved by compressing and encrypting the sampled data. This paper investigates in detail the leakage of information from Skype, a widely used VoIP application. In this research, it has been demonstrated by using the dynamic time warping (DTW) algorithm, that sentences can be identified with an accuracy of 60%. The results can be further improved by choosing specific training data. An approach involving the Kalman filter is proposed to extract the kernel of all training signals.

Remembering forwards: or how to live together in the future with divided memories

Memory is thought to be about the past. The past is a problem in conflict transformation. This lecture suggests memory can also be about the future. It introduces the notion of remembering forwards, which is contrasted with remembering backwards. The distinction between these two forms of remembering defines the burden of memory in post-conflict societies generally and specifically in Ireland. In societies emerging out of conflict, where divided memories in part constituted the conflict, social memory privileges remembering backward. Collective and personal memories elide within social memory to perpetuate divided group identities and contested personal narratives. Above all, social memory works to arbitrate the future, by predisposing an extreme memory culture that locks people into the past. Forgetting the past is impossible and undesirable. What is needed in societies emerging out of conflict is to be released from the hold that oppressive and haunting memories have over people. This lecture will suggest that this is found in the idea of remembering forwards. This is not the same as forgetting. It is remembering to cease to remember oppressive and haunting memories. It does not involve non-remembrance but active remembering: remembering to cease to remember the past. While the past lives in us always, remembering forwards assists us in not living in the past. Remembering forwards thus allows us to live in tolerance in the future despite the reality that divided memories endure and live on. The lecture further argues that these enduring divided memories need to be reimagined by the application of truth, tolerance, togetherness and trajectory. The lecture suggests that it is through remembering forwards with truth, tolerance, togetherness and trajectory that people in post-conflict societies can inherit the future despite their divided pasts and live in tolerance in the midst of contested memories.

Abnormal Pedestrian Trajectory analysis based on arbitrary-length clustering

This papers examines the use of trajectory distance measures and clustering techniques to define normal
and abnormal trajectories in the context of pedestrian tracking in public spaces. In order to detect abnormal
trajectories, what is meant by a normal trajectory in a given scene is firstly defined. Then every trajectory
that deviates from this normality is classified as abnormal. By combining Dynamic Time Warping and a
modified K-Means algorithms for arbitrary-length data series, we have developed an algorithm for trajectory
clustering and abnormality detection. The final system performs with an overall accuracy of 83% and 75%
when tested in two different standard datasets.

'That Puissant City': John Milton's Roman Sojourns 1638-1639

John Milton’s sojourns in Rome (1638-9) are attested by his comments in Defensio Secunda, by the minutes of the English College, by Latin encomia which he received from Roman academicians, and, not least, by his Latin letter to Lucas Holstenius (19/29 March 1639), and several Latin poems which he composed in the course of his residency in the capital city: Ad Salsillum, and three Latin epigrams extolling the praises of the virtuosa soprano, Leonora Baroni. Read together, these texts serve to reveal much about Milton’s participation in, and reaction to, the ‘Puissant City’, (History of Britain, Bk 2).

The present monograph presents fresh evidence of Milton's integration into the academic and cultural life of seventeenth-century Rome. It argues that his links with two Roman academies: the Accademia dei Fantastici and Accademia degli Umoristi constitute a sustained participation in an academic community paralleling that of his independently attested performance in Florentine academies (on which I have published extensively). It also investigates his links with Alessandro Cherubini, David Codner, Giovanni Batista Doni, and the Baroni circle hymned in three published anthologies.

Chapter 1: Milton and the Accademia dei Fantastici investigates the cultural climate surrounding Milton's Ad Salsillum by examining two of that academy's publications: the Poesie dei Signori Accademici Fantastici di Roma (Rome, 1637) and the Academia Tenuta da Fantastici a. 12 di Maggio 1655 (Rome, 1655), the latter celebrating the creation of Fabio Chigi as Pope Alexander VII on 5 April 1655. Read in a new light, Milton’s self-fashioning, it is argued, takes its place not only alongside Salzilli’s encomium in Milton's honour, and his Italian sonnets in the 1637 Poesie, but also in relation to other poems in that collection, and the academy's essentially Catholic eulogistic trend. The chapter also provides fresh evidence of Salzilli’s survival of the illness described in Milton’s poem by his epistolary correspondence with Tomaso Stigliani.

Chapter 2: Milton and the Vatican argues for links between Milton’s Latin letter to Holstenius and a range of Holstenius’ published works: his edition of the axioms of the later Pythagoreans gifted by him to Milton, and his published neo-Platonic works. This is achieved by mutual appropriation of Similitudes in a series of Miltonic similes, the anabasis/katabasis motifs in a reworking of the Platonic theory of the transmigration of souls, and allusion to etymological details highlighted in Holstenius’ published editions. The chapter also reveals Milton’s alertness to typographical procedures and, by association, to Holstenius’ recent role (1638) as Director of the press of the Biblioteca Vaticana.

Chapter 3: Milton and the Accademia degli Umoristi argues for Milton’s likely participation in this Roman academy, as suggested by his links with its members. His three Latin epigrams in praise of Leonora Baroni, the only female member of the Umoristi, have hitherto been studied in relation to the 1639 Applausi in her honour. In a new reading, Milton, it is suggested, invokes and interrogates Catholic doctrine before a Catholic audience only to view the whole through the lens of a neo-Platonic Hermeticism (by echoing the phraseology of the sixteenth-century Franciscan Hannibal Rosselli) that refreshingly transcends religious difference. Crucially, the hitherto neglected L’Idea della Veglia (Rome, 1640) includes further encomiastic verse, sonnets to, and by Leonora, and details of the conversazioni hosted by her family at the precise time of Milton’s Roman sojourns. Milton may well have been a participant. The chapter concludes in an assessment of his links with the youthful prodigy Alessandro Cherubini, and of his audience with Francesco Barberini.

Chapter 4: Milton at a Roman Opera analyses the potential impact of ‘Chi Soffre, Speri’, which he attended on 18/28 February 1639, mounted by Francesco Barberini to inaugurate the recently completed theatre of the Palazzo Barberini. A detailed analysis of the opera's libretto, music, and theatricality casts a backward glance to Milton's Comus, and a forward glance to Paradise Lost. It also assesses Milton’s musical interests at this time, as attested by his links with Doni, and his purchase of works by Monteverdi and others.

Chapter 5: Milton’s English Connections in Rome develops the work of Miller and Chaney by investigating Milton’s co-diners at the English College in Rome on 30 October 1638, and by analysing his links between David Codner (alias Matteo Selvaggio), and the family of Jane Savage, Marchioness of Winchester, lamented by Milton in 1631. It also assesses his potential relations with the Englishman Thomas Gawen, who ‘accidentally sometimes fell into the company of John Milton’ (Antony Wood).

Compared with specialist registrars, experienced staff nurses shorten the duration of weaning neonates from mechanical ventilation

OBJECTIVE: To compare the overall performance of specially trained neonatal nurses acting autonomously, unsupervised, and without a protocol with specialist registrars when weaning neonates from mechanical ventilation.

DESIGN: Prospective, randomized, controlled trial.

SETTING: A single neonatal intensive care unit.

PATIENTS: Neonates requiring conventional mechanical ventilation (n = 50).

INTERVENTIONS: Infants on conventional ventilation were randomly assigned to receive either nurse-led (n = 25) or registrar-led (n = 23) weaning. A total of 48 infants completed the study (two infants in the registrar group were excluded when their parents withdrew consent).

MEASUREMENTS AND MAIN RESULTS: The main outcome measure, median weaning time, was 1200 mins (95% confidence interval [CI], 621-1779 mins) in the nurse group and 3015 mins (95% CI, 2650-3380 mins) in the registrar group (p = .0458). The median time from treatment assignment to the first ventilator change was 60 mins (95% CI, 52-68 mins) in the nurse group and 120 mins (95% CI, 103-137 mins) in the registrar group (p = .35). On average, the nurses made ventilator changes every 4.5 hrs (95% CI, 2.9-6 hrs) and the registrars every 7.2 hrs (95% CI, 5.4-9 hrs; p = .003). The median number (range) of backward steps taken per infant was 0 (0-5 steps) in the nurse group and 1 (0-5 steps) in the registrar group (p = .019).

CONCLUSIONS: The findings of this study suggest that additional domains of neonatal critical care could be reviewed for their potential transfer to appropriately prepared nurses.