Miracle-dz/UniFAR-FTUs huggingface dataset:
RESEARCH INTERESTS RESEARCH PROJECTS

2005–present HiStar: a secure operating system [2]. Led the HiStar project on designing and developing a new operating system that allows applications to minimize the amount of trusted code. HiStar allows applications to specify precise data security policies by specifying how different information can flow through the system. As a result, small amounts of trusted code can reason about the security of large, complex, and potentially buggy applications. HiStar enforces precise information flow restrictions by breaking down and refactoring traditional OS abstractions into six basic types of objects and a small number of operations that make all information flow explicit.
On scaling the mean momentum balance and its solutions in turbulent Couette–Poiseuille flow

The statistical properties of fully developed planar turbulent Couette–Poiseuille flow result from the simultaneous imposition of a mean wall shear force together with a mean pressure force. Despite the fact that pure Poiseuille flow and pure Couette flow are the two extremes of Couette–Poiseuille flow, the statistical properties of the latter have proved resistant to scaling approaches that coherently extend traditional wall flow theory. For this reason, Couette–Poiseuille flow constitutes an interesting test case by which to explore the efficacy of alternative theoretical approaches, along with their physical/mathematical ramifications. Within this context, the present effort extends the recently developed scaling framework of Wei et al. (2005a) and associated multiscaling ideas of Fife et al. (2005a, b) to fully developed planar turbulent Couette–Poiseuille flow. Like Poiseuille flow, and contrary to the structure hypothesized by the traditional inner/outer/overlap-based framework, with increasing distance from the wall, the present flow is shown in some cases to undergo a balance breaking and balance exchange process as the mean dynamics transition from a layer characterized by a balance between the Reynolds stress gradient and viscous stress gradient, to a layer characterized by a balance between the Reynolds stress gradient (more precisely, the sum of Reynolds and viscous stress gradients) and mean pressure gradient. Multiscale analyses of the mean momentum equation are used to predict (in order of magnitude) the wall-normal positions of the maxima of the Reynolds shear stress, as well as to provide an explicit mesoscaling for the profiles near those positions. The analysis reveals a close relationship between the mean flow structure of Couette–Poiseuille flow and two internal scale hierarchies admitted by the mean flow equations. The averaged profiles of interest have, at essentially each point in the channel, a characteristic length that increases as a well-defined ‘outer region’ is approached from either the bottom or the top of the channel. The continuous deformation of this scaling structure as the relevant parameter varies from the Poiseuille case to the Couette case is studied and clarified.
Discriminative Learning Using Boosted Generative Models

Discriminative learning, or learning for classification, is a common learning task that has been addressed in a variety of frameworks. One approach is to design a complex classifier, such as a support vector machine, that explicitly minimizes classification error. Alternatively, an ensemble of weak classifiers can be trained using boosting [4]. However, in some situations it may be desirable to use a generative model, such as a Bayesian network, for classification. One option in this case is to train the generative model discriminatively. However, discriminative training of generative models can be computationally demanding [1, 3, 2]. In contrast, maximum likelihood learning in a generative framework can often be done efficiently, but the classification performance is frequently undermined by the need to make strong assumptions about the structure of the model and the independence of the features. In this work we propose a new framework for discriminative training of generative models. Similar to a standard boosting approach, we recursively form an ensemble of classifiers. However in contrast to situations where the weak classifiers are trained discriminantly, the “weak classifiers” in our method are trained generatively, to maximize the likelihood of the weighted data. This approach has two benefits. First, our classifiers are constructed from generative models. This is important in many practical cases when generative models, such as Bayesian networks or HMM, are desired or appropriate (e.g., sequence modeling). Second, the ML training of generative models is often much more efficient than discriminative training. The combination of discriminative weighting of the data with generative training of the intermediate models yields a computationally efficient method for training generative classifiers. We introduce a new discriminative structure learning method, called Boosted Augmented Naive Bayes (BAN) classifier. We demonstrate that BAN is easy to implement and computationally efficient. BAN’s performance on a large suite of benchmark datasets is superior to naive Bayes, TAN, and generatively-trained Bayesian networks. It is competitive with BNC-MDL, BNC-2P, ELR-NB, and ELR-TAN and requires significantly less computation during training. We also demonstrate the benefit of parameter boosting in discriminative training of dynamic Bayesian network classifiers. Our initial results show that boosted DBNs always outperform models which are trained using standard maximum likelihood methods. The computational complexity of our weighted maximum likelihood approach is within a constant factor of standard maximum likelihood learning, making it ideal for discriminative training of complex models over large datasets.
Activity supervision tool using Non-Intrusive Load Monitoring Systems

Non-Intrusive Load Monitoring System (NILM) is a collection of techniques and technologies aiming to disaggregate the energy consumption from smart meters to device level consumption. This disaggregation allows us to supervise the activity related to particular devices (e.g. machines in factories or appliances in houses) without intrusiveness along the time. Furthermore, NILM systems enable large scale deployment and low cost expenses. In this paper, we present a new activity monitoring approach based on the use of a NILM system, firstly developed for elderly people activity monitoring at home, which could be potentially applicable to factory automation to supervise the activity of a particular machine for maintenance or other purposes. Our approach monitors the activity of many appliances in households and rates the total activity in terms of “normality” in a predetermined period of time, hence, deviations in the pattern can be detected.
Tunnelling Effect and Hawking Radiation from a Vaidya Black Hole

In this paper, we extend Parikh’ work to the non-stationary black hole. As an example of the non-stationary black hole, we study the tunnelling eﬀect and Hawking radiation from a Vaidya black hole whose Bondi mass is identical to its mass parameter. We view Hawking radiation as a tunnelling process across the event horizon and calculate the tunnelling prob-ability. We ﬁnd that the result is diﬀerent from Parikh’s work because dr H dv is the function of Bondi mass m ( v ).
The Prognostic Role of p16 Expression in Tonsil Cancer Treated by Either Surgery or Radiation

OBJECTIVES Although human papillomavirus (HPV) infection is considered as a favorable prognostic factor in oropharyngeal cancer, the prognosis of HPV-associated tonsil cancer has rarely been studied especially when surgery was the main treatment. In this study, the authors investigated the effect of p16 over-expression (HPV infection) on tonsil cancer prognosis according to the type of treatment, HPV presence by PCR, and expression of p53 and epidermal growth factor receptor (EGFR) by immunohistochemistry (IHC). METHODS Medical records of 33 tonsil cancer patients were reviewed. Using formalin-fixed and paraffin-embedded tumor specimens, PCR-based genotyping of HPV and IHC of p16, p53 and EGFR were performed. The effects of HPV presence and the expression of IHC markers were analyzed on the recurrence-free survival. Five-year disease-free survival (DFS) rates were evaluated according to p16 expression status. RESULTS An over-expression of p16 was observed in 27 (81.9%) out of 33 cases. Surgery-based treatment was provided for 21 (63.6%) patients. There was no association between p16 immunoreactivity and HPV presence, nor with p53 and EGFR expression. Regardless of main treatment modalities, five-year DFS did not differ by p16 expression status (P=0.051). However, over-expression of p16 was associated with a lower recurrence in multivariable analyses (P=0.046). CONCLUSION Regardless of main treatment modalities, an over-expression of p16 (HPV infection) is associated with a lower recurrence in tonsil cancers. However it is not associated with simple HPV presence or p53 and EGFR over-expression.
Neurophysiological signature of effective anticipatory task‐set control: a task‐switching investigation

Changing between cognitive tasks requires a reorganization of cognitive processes. Behavioural evidence suggests this can occur in advance of the stimulus. However, the existence or detectability of an anticipatory task‐set reconfiguration process remains controversial, in part because several neuroimaging studies have not detected extra brain activity during preparation for a task switch relative to a task repeat. In contrast, electrophysiological studies have identified potential correlates of preparation for a task switch, but their interpretation is hindered by the scarcity of evidence on their relationship to performance. We aimed to: (i) identify the brain potential(s) reflecting effective preparation for a task‐switch in a task‐cuing paradigm that shows clear behavioural evidence for advance preparation, and (ii) characterize this activity by means of temporal segmentation and source analysis. Our results show that when advance preparation was effective (as indicated by fast responses), a protracted switch‐related component, manifesting itself as widespread posterior positivity and concurrent right anterior negativity, preceded stimulus onset for ∼300 ms, with sources primarily in the left lateral frontal, right inferior frontal and temporal cortices. When advance preparation was ineffective (as implied by slow responses), or made impossible by a short cue–stimulus interval (CSI), a similar component, with lateral prefrontal generators, peaked ∼300 ms poststimulus. The protracted prestimulus component (which we show to be distinct from P3 or contingent negative variation, CNV) also correlated over subjects with a behavioural measure of preparation. Furthermore, its differential lateralization for word and picture cues was consistent with a role for verbal self‐instruction in preparatory task‐set reconfiguration.
Microphone array for increasing mutual information between sound sources and observation signals

We investigated the basic principle of how spatial signals should be captured with a microphone array to estimate each source signal and its practical implementation. Most conventional studies on array signal processing have been focused on the design of beamforming and Wiener filters. To achieve further effective noise reduction, designing an optimum array structure to segregate a target from other noises is necessary. We found the optimum structure of the spatial correlation matrix to estimate each source signal. This is achieved by receiving signals whose eigenvalues of the spatial correlation matrix are homogenized. To homogenize the eigenvalues of the spatial correlation matrix while maintaining a short impulse response length, we propose an array structure composed of parabolic reflectors and 96 microphones. Through experiments using the proposed array structure, we confirmed that the eigenvalues of the spatial correlation matrix was asymptotically homogenized and that sharp directivity could be formed.
Satisfiers and dissatisfiers: A two-factor model for website design and evaluation

Proliferating Web-user interface studies prompt a need for theoretical approaches. This study presents a two-factor model that can guide Website design and evaluation. According to the model, there are two types of Website design factors: hygiene and motivator. Hygiene factors are those whose presence make a Website functional and serviceable, and whose absence causes user dissatisfaction (thus dissatisfiers). Motivator factors, on the other hand, are those that add value to the Website by contributing to user satisfaction (thus satisfiers). An empirical study is conducted in two phases. In Phase I, 44 core features and 12 categories of features were identified by a total of 76 subjects as Web design factors. In Phase II, 79 different subjects distinguished hygiene and motivator factors in the context of a particular Website (CNN.com). The results showed that the two-factor model provides a means for Web-user interface studies. In addition, Subjects in Phase II commented that, as time passes or familiarity increases with certain design factors, their identification of what are hygiene and motivator factors might change, promoting further investigation and possible expansion of the model. Suggestions for Website designs and evaluation, and further research directions are provided.
TCP/IP Performance over 3G Wireless Links with Rate and Delay Variation

Abstract Wireless link losses result in poor TCP throughput since losses are perceived as congestion by TCP, resulting in source throttling. In order to mitigate this effect, 3G wireless link designers have augmented their system with extensive local retransmission mechanisms. In addition, in order to increase throughput, intelligent channel state based scheduling have also been introduced. While these mechanisms have reduced the impact of losses on TCP throughput and improved the channel utilization, these gains have come at the expense of increased delay and rate variability. In this paper, we comprehensively evaluate the impact of variable rate and variable delay on long-lived TCP performance. We propose a model to explain and predict TCP’s throughput over a link with variable rate and/or delay. We also propose a network-based solution called Ack Regulator that mitigates the effect of variable rate and/or delay without significantly increasing the round trip time, while improving TCP performance by up to 100%.
Expression of the Murine Norovirus (MNV) ORF1 Polyprotein Is Sufficient to Induce Apoptosis in a Virus-Free Cell Model

Investigations into human norovirus infection, replication and pathogenesis, as well as the development of potential antiviral agents, have been restricted by the lack of a cell culture system for human norovirus. To date, the optimal cell culture surrogate virus model for studying human norovirus biology is the murine norovirus (MNV). In this report we generate a tetracycline-regulated, inducible eukaryotic cell system expressing the entire MNV ORF1 polyprotein. Once induced, the MNV ORF1 polyprotein was faithfully processed to the six mature non-structural proteins that predominately located to a discrete perinuclear region, as has been observed in active MNV infection. Furthermore, we found that expression of the ORF1 polyprotein alone was sufficient to induce apoptosis, characterised by caspase-9 activation and survivin down-regulation. This cell line provides a valuable new tool for studying MNV ORF1 non-structural protein function, screening for potential antiviral agents and acts as a proof-of-principle for such systems to be developed for human noroviruses.
A massive , cooling-flow-induced starburst in the core of a highly luminous cluster of galaxies

Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. In the cores of some galaxy clusters the hot intracluster plasma is dense enough that it should cool radiatively in the cluster's lifetime 1–3 , leading to continuous " cooling flows " of gas sinking towards the cluster center, yet no such cooling flow has been observed. The low observed star formation rates 5, 35 and cool gas masses 6 for these " cool core " clusters suggest that much of the cooling must be offset by astrophysical feedback to prevent the formation of a runaway cooling flow 7–10. Here we report X-ray, optical, and infrared observations of the galaxy cluster SPT-CLJ2344-4243 11 at z = 0.596. These observations reveal an exceptionally luminous (L 2−10 keV = 8.2 × 10 45 erg s −1) galaxy cluster which hosts an extremely strong cooling flow (˙ M cool = 3820 ± 530 M yr −1). Further, the central galaxy in this cluster appears to be experiencing a massive starburst (740 ± 160 M yr −1), which suggests that the feedback source responsible for preventing runaway cooling in nearby cool core clusters may not yet be fully established in SPT-CLJ2344-4243. This large star formation rate implies that a significant fraction of the stars in the central galaxy of this cluster may form via accretion of the intr-acluster medium, rather than the current picture of central galaxies assembling entirely via mergers. The galaxy cluster SPT-CLJ2344-4243 was discovered by the South Pole Telescope (hereafter SPT 12) via the Sunyaev-Zel'dovich (SZ) effect, with an initial estimated mass of M 200 ∼16.6 × 10 14 M 11. These data were supplemented with new broadband optical g, r, i, z imaging from the Mosaic II camera on the Blanco 4-m telescope (Figure 1), optical multi-object spectroscopy 2 using GMOS on the Gemini South 8.1-m telescope, optical long-slit spectroscopy using IMACS on the 6.5-m Magellan telescope, near-infrared long-slit spectroscopy using FIRE on the 6.5-m Magellan telescope, mid–far infrared imaging using PACS and SPIRE on the Herschel Space Observatory , and X-ray imaging spectroscopy using the ACIS-I camera on the Chandra X-ray Observatory. Additionally, we have acquired archival near–far UV imaging from the …
Conservation for Sale: A Dynamic Common Agency Model of Natural Resource Regulation

This paper considers the regulation of a natural resource within a dynamic common agency framework. In setting harvest quotas, the regulator responds to lobbying pressure (contributions) from harvesters and conservationists. The truthful Markov perfect equilibrium stock is then an increasing function of the effective political weight for conservationists. Since the contributions to the regulator are independent of the no-regulation equilibrium, both individual and aggregate welfare may decline by adopting regulation. Indeed, harvesters operating under private property will always oppose regulation, and harvesters operating under common property will oppose regulation if their welfare is not valued highly enough by the regulator. Since conservationists' gross welfare is always improved by regulation, and since the regulator cannot fully capture their rents, conservationists will support regulation. For regulation to be supported by harvesters and conservationists, it is more important that the welfare of harvesters be taken into account by the regulator. This is because harvesters, like conservationists, value the stock, but conservationists, unlike harvesters, place no value on the harvests.
Developmental dyspraxia is not limited to imitation in children with autism spectrum disorders

Impaired imitation of skilled gestures is commonly reported in autism. Questions, however, remain as to whether impaired imitation is associated with a more generalized deficit in performance of gestures consistent with a dyspraxia and whether the pattern of errors differs from that observed in typically developing children. To address these questions, praxis in 21 high-functioning children with autism spectrum disorders (ASD) was compared with 24 typically developing controls using a traditional approach in which performance was evaluated through detailed examination of error types. Children with ASD produced significantly fewer correct responses not only during Gesture to Imitation, but also during Gesture to Command and with Tool Use. The pattern of errors in ASD was similar to that of controls with spatial errors being most common in both groups; however, body-part-for-tool errors were more common in children with ASD, suggesting dyspraxia is not entirely attributable to motor deficits. The findings suggest that autism is associated with a generalized praxis deficit, rather than a deficit specific to imitation. In a developmental disorder such as autism, the findings may reflect abnormalities in frontal/parietal–subcortical circuits important for acquisition (i.e., learning) of sensory representations of movement and/or the motor sequence programs necessary to execute them. (JINS, 2006, 12, 314–326.)
An Effective Approach for Compression of Bengali Text

In this paper, we propose an effective and efficient approach for compressing Bengali Text. This paper focuses on a methodical study on Bengali text compression techniques. The main target of this research is to provide a framework for Bengali text compression; which ensures a simple and computationally inexpensive effective scheme for Bengali text compression. The proposed Bengali text compression scheme is aimed to encompass the low-overhead data communication and management framework for battery powered, energy constrained devices. The current approaches of data compression and their correspondence, usage and efficiency for compressing Bengali text are also presented in this paper. The comparative analysis of existing compression techniques and proposed approach in terms of time and space complexity along with compression ratio has been integrated. We also present an effective scheme for constructing the training platform or knowledgebase for obtaining compression, as there is no specific tertiary dictionary based Bengali text compression scheme is available for research. The main aspect of the proposed scheme is the integration of string ranking scheme for indexing the source text to achieve hierarchical compression scheme. Static coding is also employed in the proposed scheme to encode the data for compression. This paper also incorporates power consumption analysis of proposed compression scheme along with the performance analysis in terms of compression ratio.