Miracle-dz/UniFAR-FTUs huggingface dataset:
Minimum strictly convex quadrangulations of convex polygons

We present a linear–time algorithm that decomposes a convex polygon conformally into a minimum number of strictly convex quadrilaterals. Moreover, we characterize the polygons that can b e decomposed without additional vertices inside the polygon, a nd we present a linear–time algorithm for such decompositions, t oo. As an application, we consider the problem of constructing a mi ni um conformal refinement of a mesh in the three–dimensional spac e, which approximates the surface of a workpiece. It turns out t ha this problem isNP–hard, and we present a linear-time algorithm with a constant approximation ratio of 4.
Image Segmentation of Homogeneous Intensity Regions using Wavelets based Level Set

This paper proposes an image segmentation method that integrates a wavelets feature, which is able to enhance the dissimilarity between regions with low variations in intensity. This feature is integrated to formulate a new level set based active contour model that addresses the segmentation of regions with highly similar intensities, which do not have clear boundaries between them. In the first phase, the strength of wavelet transform will be adapted to formulate wavelet energies. The second phase will be dedicated to regularize a new wavelets based level set formulation. This formulation is composed of two terms that guide the contour, the wavelet energy incorporated region term and the contour smoothness term. This approach is useful and suitable for segmentation of regions within an image with improper boundaries.
On the perpetual American put options for level dependent volatility models with jumps

We prove that the perpetual American put option price of level dependent volatility model with compound Poisson jumps is convex and is the classical solution of its associated quasi-variational inequality, that it is $C^2$ except at the stopping boundary and that it is $C^1$ everywhere (i.e. the smooth pasting condition always holds).
Fantastic 4 system for NIST 2015 Language Recognition Evaluation

This article describes the systems jointly submitted by Institute for Infocomm (I$^2$R), the Laboratoire d'Informatique de l'Universit\'e du Maine (LIUM), Nanyang Technology University (NTU) and the University of Eastern Finland (UEF) for 2015 NIST Language Recognition Evaluation (LRE). The submitted system is a fusion of nine sub-systems based on i-vectors extracted from different types of features. Given the i-vectors, several classifiers are adopted for the language detection task including support vector machines (SVM), multi-class logistic regression (MCLR), Probabilistic Linear Discriminant Analysis (PLDA) and Deep Neural Networks (DNN).
Crisis management using multiple camera surveillance systems

During recent disasters such as tsunami, flooding, hurricanes, nuclear disaster, earthquake people have to leave their living areas for their own safety. But it proves that some people are not informed about the evacuation, or are not willing or able to leave or don’t know how to leave the hazardous areas. The topic of the paper is how to adapt current video surveillance systems along highway and streets to semi-automatic surveillance systems. When a suspicious event is detected a human operator in the control room has to be alerted to take appropriate actions. The architecture of the system and main modules are presented in the paper. Different algorithms to detect localize and track people are published by the authors elsewhere but are summarized in the current paper. The system has been tested in a real life environment and the test results are presented in the paper.
Survival Nomogram for Curatively Resected Korean Gastric Cancer Patients: Multicenter Retrospective Analysis with External Validation

Background A small number of nomograms have been previously developed to predict the individual survival of patients who undergo curative resection for gastric cancer. However, all were derived from single high-volume centers. The aim of this study was to develop and validate a nomogram for gastric cancer patients using a multicenter database. Methods We reviewed the clinicopathological and survival data of 2012 patients who underwent curative resection for gastric cancer between 2001 and 2006 at eight centers. Among these centers, six institutions were randomly assigned to the development set, and the other two centers were assigned to the validation set. Multivariate analysis using the Cox proportional hazard regression model was performed, and discrimination and calibration were evaluated by external validation. Results Multivariate analyses revealed that age, tumor size, lymphovascular invasion, depth of invasion, and metastatic lymph nodes were significant prognostic factors for overall survival. In the external validation, the concordance index was 0.831 (95% confidence interval, 0.784–0.878), and Hosmer-Lemeshow chi-square statistic was 3.92 (P = 0.917). Conclusions We developed and validated a nomogram to predict 5-year overall survival after curative resection for gastric cancer based on a multicenter database. This nomogram can be broadly applied even in general hospitals and is useful for counseling patients, and scheduling follow-up.
Species – Area Curves based on Geographic Range and Occupancy

The species–area relationship (SPAR) is one of the cornerstones of ecological science. We use information about the geographic distribution of species to deduce the SPAR from a new model; our results complement existing ones that explain SPARs on the basis of equilibrium theory or species-abundance relationships. We assume that each species is characterized by a geographic range and level of abundance (occupancy). We use a mixture of analytical (in one dimension) and numerical (in two dimensions) methods to create SPARs that are concave and can often be parametrized by a power law with exponent less than 1. We show that the main features of the SPAR depend upon the way that one censuses patches and on the characteristics (range and occupancy) of the species. Our approach identifies the key field variables that need to be measured and have implication for conservation, particularly when one estimates the number of species lost after habitat destruction. 7 1999 Academic Press
SLAs A Key Commercial Tool

SLAs are likely to become a key tool for the service provider in offering commercial services in Service Oriented Architectures. A well chosen SLA helps in the establishment of credibility for the service provider; it is a means to attract customers in a competitive environment and establishes the customer-provider business relationship. It may help to retain customers and will be used as a mechanism for service differentiation. SLAs have many complex issues associated with them and are difficult to use and understand, particularly in a value chain, so a common approach to the representation of SLAs is desirable. Most of the current SLA representations focus almost exclusively on the functional aspects of the service being offered such as performance levels and ignore the non-functional factors that have a considerable influence on the successful establishment of a business relationship. Automation of this process is further inhibited by the confidentiality requirements that often surround commercial SLAs.
Keeping up with our students: The evolution of technology and standards in art education

ABSTRACT This article addresses the standards of technology in the visual arts, arguing the standards function as de facto policy, the guidelines that shape what teachers teach. In this study, we investigate how art education standards approach technology as a teaching tool and artmaking medium, analyzing the current National Visual Arts Standards, the 21st Century Skills, the National Art Education Association (NAEA) Standards for Art Teacher Preparation, the NAEA Professional Standards for Visual Arts Educators, and how 26 university art education programs teach technology. Because a new set of digital standards were developed as media arts, separate from the visual arts, we believe that media arts should be considered a subset of the larger umbrella of visual arts, seeing visual art educators are the best equipped to address the new digital media arts standards and forms of making. Finally the article makes suggestions about how university art teacher preparation programs can redirect their courses to better relate to contemporary art practices, current educational uses of technology, and the world of ubiquitous computing.
Pruning near-duplicate images for mobile landmark identification: A graph theoretical approach

Automatic landmark identification is one of the hot research topics in computer vision domain. Efficient and robust identification of landmark points is a challenging task, especially in a mobile context. This paper addresses the pruning of near-duplicate images for creating representative training image sets to minimize overall query processing complexity and time. We prune different perspectives of real world landmarks to find the smallest set of the most representative images. Inspired from graph theory, we represent each class in a separate graph using geometric verification of well-known RANSAC algorithm. Our iterative method uses maximum coverage information in each iteration to find the minimum representative set to reduce and prioritize the images of the initial dataset. Experiments on Paris dataset show that the proposed method provides robust and accurate results using smaller subsets.
The effect of metallicity on the Cepheid period-luminosity relation

We present preliminary results of an observational campaign devoted to establishing the influence of chemical composition on the Cepheid Period-Luminosity relation. The data are in good agreement with theoretical predictions based on non-linear convective models, suggesting a fairly strong dependence of the Period-Luminosity relation on metallicity in the sense of more metal rich stars being intrinsically fainter than otherwise expected. Our data indicate that the error on the inferred distance can be as large as 10% if the role of metallicity is neglected.
AdAttester: Secure Online Mobile Advertisement Attestation Using TrustZone

Mobile advertisement (ad for short) is a major financial pillar for developers to provide free mobile apps. However, it is frequently thwarted by ad fraud, where rogue code tricks ad providers by forging ad display or user clicks, or both. With the mobile ad market growing drastically (e.g., from $8.76 billion in 2012 to $17.96 billion in 2013), it is vitally important to provide a verifiable mobile ad framework to detect and prevent ad frauds. Unfortunately, this is notoriously hard as mobile ads usually run in an execution environment with a huge TCB. This paper proposes a verifiable mobile ad framework called AdAttester, based on ARM? s TrustZone technology. AdAttester provides two novel security primitives, namely unforgeable clicks and verifiable display. The two primitives attest that ad-related operations (e.g., user clicks) are initiated by the end user (instead of a bot) and that the ad is displayed intact and timely. AdAttester leverages the secure world of TrustZone to implement these two primitives to collect proofs, which are piggybacked on ad requests to ad providers for attestation. AdAttester is non-intrusive to mobile users and can be incrementally deployed in existing ad ecosystem. A prototype of AdAttester is implemented for Android running on a Samsung Exynos 4412 board. Evaluation using 182 typical mobile apps with ad frauds shows that AdAttester can accurately distinguish ad fraud from legitimate ad operations, yet incurs small performance overhead and little impact on user experience.
Libckpt: Transparent Checkpointing under UNIX

Checkpointing is a simple technique for rollback recovery: the state of an executing program is periodically saved to a disk file from which it can be recovered after a failure. While recent research has developed a collection of powerful techniques for minimizing the overhead of writing checkpoint files, checkpointing remains unavailable to most application developers. In this paper we describe libckpt, a portable checkpointing tool for Unix that implements all applicable performance optimizations which are reported in the literature. While libckpt can be used in a mode which is almost totally transparent to the programmer, it also supports the incorporation of user directives into the creation of checkpoints. This user-directed checkpointing is an innovation which is unique to our work.
Performance Analysis of UWB Autocorrelation Receivers Over Nakagami-Fading Channels

We study the performance of the autocorrelation receiver (AcR) with the transmitted-reference (TR) signaling scheme in the multipath UWB channel, where the fading of each resolvable multipath component is characterized by: 1) Nakagami distribution; 2) arbitrary fading parameter; and 3) arbitrary average power. The analysis, compared to conventional Rake receivers, is complicated by the fact that the instantaneous signal-to-noise ratio (SNR) at the AcR output is a nonlinear function of the instantaneous SNR at the receiver input, the latter given by the sum of the SNRs of each resolvable multipath component. Based on the derivation of exact and approximated expressions for the probability density function (pdf) of the output SNR, we evaluate several indicators of the receiver performance, such as: 1) average SNR; 2) amount of fading; 3) outage probability; and 4) average bit-error probability (BEP); all are given in a closed-form. Remarkably, we show that the pdf of the output SNR can be modeled as a gamma distributed random variable, which allows us to write the average BEP in terms of the well-known hypergeometrical Gaussian function. An approximate, yet accurate, expression of the integration time minimizing the average BEP is also derived.
SIMS: A Comprehensive Approach for a Secure Instant Messaging Sifter

Instant messaging (IM) stands for a visual mode of communication with the chance of real time responses but without (needed or wished) face-to-face contacts. In particular, youngsters prefer instant messengers to kill time if they are bored and nothing else within range interests them. Harmfully, they may get in touch with inappropriate language there. Much worse, their habitation in such virtual venues allures child molesters as well. Even chatting majors may be sighted and hassled to obtain exploitable private data from them. This paper aids by evaluating a comprehensive threat model for censored IM traffic in order to draft a security policy for IM clients, transmission facilities and IM platforms with a bulk of desired protection properties. Finally, an innovative IM architecture kit becomes conceptually introduced that meets all advised requirements and therefore mitigates the threats. It contains a secure IM filter that guarantees not only authenticity, integrity, privacy and resilience but also prevention of abusive language, cyber bullying, molestation and others exploits.
In vivo neuronal tract tracing using manganese‐enhanced magnetic resonance imaging

Development of efficient imaging techniques to trace neuro nal connections would be very useful. Manganese ion (Mn2+) is an excellent T1 contrast agent for magnetic resonance imaging (MRI). Four reports utilizing radioactive Mn2+ in fish and rat brain indicate that Mn2+ may be useful for tracing neuronal connections. Therefore, the purpose of this work was to determine if Mn2+ can be used as an in vivo MRI neuronal tract tracer. The results indicate that topical admin istration of MnCI2 solution to the naris of mice as well as to the retinal ganglion cells via intravitreal injection leads to en hancement of contrast along the respective pathways. There fore, application of Mn2+ to neurons allows the use of MRI to visualize neuronal connections.
The Alternating Linear Scheme for Tensor Optimisation in the TT Format

Recent achievements in the field of tensor product approximation [11, 32] provide promising new formats for the representation of tensors in form of tree tensor networks. In contrast to the canonical r-term representation (CANDECOMP, PARAFAC), these new formats provide stable representations [14], while the amount of required data is only slightly larger. The TT format [28, 29, 31], a simple special case of the hierarchical Tucker format [11], is a prototype for such a practical low rank tensor representation, corresponding to the method of matrix product states (MPS) known from quantum information theory. In this article, we consider two versions of a generalised alternating least square scheme that can be used to treat optimisation tasks in the TT format: A generalisation of the well-known Alternating Least Squares (ALS) algorithm, and a modified approach (MALS) that enables dynamical rank adaptation. For the examples of linear equations and eigenvalue equations, we derive according working equations for the micro-iteration steps and define so-called retraction operators, by the help of which it can easily be shown that many structural properties of the original problems transfer to the micro-iterations. As a practical example of a high-dimensional eigenvalue problem, we take a particular look at the Fock space approach utilised for treatment of the electronic Schrödinger equation and show that the MALS algorithm for this problem corresponds to the Density Matrix Renormalisation Group (DMRG) algorithm, a successful method for the computation of spin chains [40]. We finish with some numerical examples that confirm the positive experiences concerning the stability of the TT decomposition and of ALS and MALS, but also show that in some cases, high TT ranks are required during the iterative approximation of low-rank tensors, showing some potential of improvement.
A novel live streaming system using P2P and statistical multiplexing

In this paper, we introduce a new streaming system by employing P2P and statistical multiplexing. The proposed scheme enhances the bandwidth efficiency of the whole network. Compare to the previous proposed methods, our scheme is also better in terms of received video quality. Experiment results show the variance of PSNR of the proposed scheme is lower than that of the same other schemes. Furthermore, it works well to support more number of users as well as better QoS.
Altered White Matter Integrity in Human Immunodeficiency Virus-Associated Neurocognitive Disorder: A Tract-Based Spatial Statistics Study

Objective Human immunodeficiency virus (HIV) infection has been known to damage the microstructural integrity of white matter (WM). However, only a few studies have assessed the brain regions in HIV-associated neurocognitive disorders (HAND) with diffusion tensor imaging (DTI). Therefore, we sought to compare the DTI data between HIV patients with and without HAND using tract-based spatial statistics (TBSS). Materials and Methods Twenty-two HIV-infected patients (10 with HAND and 12 without HAND) and 11 healthy controls (HC) were enrolled in this study. A whole-brain analysis of fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity was performed with TBSS and a subsequent 20 tract-specific region-of-interest (ROI)-based analysis to localize and compare altered WM integrity in all group contrasts. Results Compared with HC, patients with HAND showed decreased FA in the right frontoparietal WM including the upper corticospinal tract (CST) and increased MD and RD in the bilateral frontoparietal WM, corpus callosum, bilateral CSTs and bilateral cerebellar peduncles. The DTI values did not significantly differ between HIV patients with and without HAND or between HIV patients without HAND and HC. In the ROI-based analysis, decreased FA was observed in the right superior longitudinal fasciculus and was significantly correlated with decreased information processing speed, memory, executive function, and fine motor function in HIV patients. Conclusion These results suggest that altered integrity of the frontoparietal WM contributes to cognitive dysfunction in HIV patients.
Two-dimensional orthoglide mechanism for revealing areflexive human arm mechanical properties

The most accurate and dependable approach to the in-vivo identification of human limb stiffness is by position perturbation. Moving the limb over a small distance and measuring the effective force gives, when states are steady, direct information about said stiffness. However, existing manipulandi are comparatively slow and/or not very stiff, such that a lumped stiffness is measured. This lumped stiffness includes the limb response during or after reflexes influenced by both, the passive musculotendon and active neuronal component. As this approach usually leads to inconsistencies between the data and the stiffness model, we argue in favour of fast, pre-reflex impedance measurements-i.e., completing the perturbation movement and collecting the data before effects of spinal reflexes or even from the motor cortex can influence the measurements. To obtain such fast planar movements, we constructed a dedicated orthoglide robot while focusing on a lightweight and stiff design. Our subject study of a force task with this device lead to very clean data with always positive definite Cartesian stiffness matrices. By representing them as ellipses, we found them to be substantially bigger in comparison to standard literature which we address to a larger number of recruited motor units. While ellipses orientation and the length of their main axis increased, the shape decreased with the exerted force. The device will be used to derive design criteria for variable-stiffness robots, and to investigate the relation between muscular activity and areflexive joint stiffness for teleoperational approaches.
FORTH-ICS / TR-171 July 1996 Credit-Flow-Controlled ATM versus Wormhole

ATM has been adopted as the main high speed technology in both wide and local area networks. When ATM is combined with credits −the flow control mechanism that is particularly suitable for local data communication− it becomes appropriate for multiprocessor interconnection networks as well. Actually, credit-flowcontrolled ATM has similarities with wormhole routing, one of the most popular architectures for MP networks: they both use credits and fixed size cells/flits, and their hardware complexity is comparable. In this paper, we show that ATM with credits performs better than wormhole routing, because ATM uses lanes more efficiently: ATM provides high throughput and low latency with much less buffer space than that required by wormhole routing; also, ATM demonstrates little sensitivity to bursty traffic, and, unlike wormhole, it is fair in terms of latency in hot-spot configurations. Our simulation uses detailed and realistic switch models, which operate at clock-cycle granularity and track closely ‘‘ATLAS I’’, a single-chip ATM switch under development.