Miracle-dz/UniFAR-FTUs huggingface dataset:
Inferring coarse views of connectivity in very large graphs

This paper presents a simple framework, called WalkAbout, to infer a coarse view of connectivity in very large graphs; that is, identify well-connected "regions" with different edge densities and determine the corresponding inter- and intra-region connectivity. We leverage the transient behavior of many short random walks (RW) on a large graph that is assumed to have regions of varying edge density but whose structure is otherwise unknown. The key idea is that as RWs approach the mixing time of a region, the ratio of the number of visits by all RWs to the degree for nodes in that region converges to a value proportional to the average node degree in that region. Leveraging this indirect sign of connectivity enables our proposed framework to effectively scale with graph size. After describing the design of WalkAbout, we demonstrate the capabilities of WalkAbout by applying it to three major OSNs ie Flickr, Twitter, and Google+) and obtaining a coarse view of their connectivity structure. In addition, we illustrate how the communities that are obtained by running a popular community detection method on these OSNs stack up against the WalkAbout-discovered regions. Finally, we examine the "meaning" of the regions obtained by WalkAbout, and demonstrate that users in the identified regions exhibit common social attributes.
Roughness parameters estimation of sea surface from SAR images

Some knowledge of sea state and conditions is input in ship detection algorithms based on inversion of scattering models for Synthetic Aperture Radar (SAR) images. This paper shows a novel technique for the estimation of roughness parameters of the sea surface from SAR images. The estimation procedure is based on the minimization of the absolute error between the Radar Cross Section (RCS) of the sea surface measured on the SAR image and the expected RCS computed using the Kirchhoff approach within the Geometrical Optics (GO) solution. The technique is tested on three different TerraSAR-X images acquired in November 2012 over the Portsmouth harbour in the UK.
Demonstration of the Greek to English METIS-II system

METIS-II, the MT system presented in this paper, does not view translation as a transfer process between a source language (SL) and a target one (TL), but rather as a matching procedure of patterns within a language pair. More specifically, translation is considered to be an assignment problem, i.e. a problem of discovering each time the best matching patterns between SL and TL, which the system is called to solve by employing patternmatching techniques. Most importantly, however, METIS-II is innovative because it does not need bilingual corpora for the translation process, but exclusively relies on monolingual corpora of the target language.
Efficient crowdsourcing contests

A principal seeks production of a good within a limited timeframe with a hard deadline, after which any good procured has no value. There is inherent uncertainty in the production process, which in light of the deadline may warrant simultaneous production of multiple goods by multiple producers despite there being no marginal value for extra goods beyond the maximum quality good produced. This motivates a crowdsourcing model of procurement. We address efficient execution of such procurement from a social planner's perspective, taking account of and optimally balancing the value to the principal with the costs to producers (modeled as effort expenditure) while, crucially, contending with self-interest on the part of all players. A solution to this problem involves both an algorithmic aspect that determines an optimal effort level for each producer given the principal's value, and also an incentive mechanism that achieves equilibrium implementation of the socially optimal policy despite the principal privately observing his value, producers privately observing their skill levels and effort expenditure, and all acting selfishly to maximize their own individual welfare. In contrast to popular "winner take all" contests, the efficient mechanism we propose involves a payment to every producer that expends non-zero effort in the efficient policy.
About left ventricular torsion, sex differences, shear strain, and diastolic heart failure.

‘An attempt at visualizing the Fourth Dimension: Take a point, stretch into a line, curl it into a circle, twist it into a sphere, and punch through the sphere’. Albert Einstein Wang et al. 1 provide novel pathophysiological information on patients with diastolic heart failure, by exploring the fourth dimension of cardiac function: left ventricular (LV) twist. The complex active and passive physiological events occurring during the heart cycle are related to the complex structure of the heart, which is a helix that contains an apex. Lower (17th century) described the cardiac helix form as having an apical vortex, in which the muscle fibres go from outside in, in a clockwise way, and from inside out, in a counter-clockwise direction.2 Nature contains many pathways of clockwise and counter-clockwise spirals (reciprocal spirals), e.g. the flower buds of a daisy, the sea shell, and even human fingertips. Dr Torrent-Guasp compared the structure of the heart with a coiled rope with a beginning and an end at the aorta and pulmonary artery; a wraparound loop called a basal loop; and a helix that he called the apical loop.3 Does this ventricular architecture correspond to a functional reality? The classical view relates to contracting and relaxing, as defined by William Harvey (1628): constricting to narrow and eject, dilating to widen and fill. In a comprehensive review, Dr Buckberg describes that the heart cycle is not merely constricting and dilating but that it comprises four fundamental motions that include narrowing, shortening, lengthening, and widening.2 The initial contraction involves the basal loop that causes constriction whereby a stiff outer shell muscle is formed that surrounds both ventricles. This corresponds to the isovolumetric, pre-ejection phase of systole. The next sequence is the contraction of the descending loop, which twists downward to thicken and cause … *Corresponding author. Tel: +32 9 240 3481, Fax: +32 9 240 4432, Email: thierry.gillebert{at}ugent.be
User profiling for answer quality assessment in Q&A communities

Collaborative Web applications, such as forums and question answering websites, help users to get answers to a wide array of questions. Given the large amount of information available, it is important to devise automatic methods that surface high quality answers. Our objective here is to determine if there are any particular aspects of a user's profile or activity in the community that can be exploited to spot high quality contributions. We first perform an in-depth analysis of the information provided by the users in their profiles in order to discriminate features that are correlated to expertise. Then, we propose an answer ranking scenario in which we assess the predictive capabilities of profile and activity related features. In our experiments, we use a large scale corpus from Stackoverflow, a very active Q&A community focused on technical topics and find that answer rankings obtained using a user model outperform a ranking based on the chronological order of answers.
Stability Oriented Overlay Multicast for Multimedia Streaming in Multiple Source Context

In this paper, we propose a new overlay multicast protocol designed for inter-active multimedia streaming applications. The protocol considers the heterogeneity of end-hosts and tries to minimize the negative impact (data outage) of end-hosts' unannounced departures. For this purpose, it concentrates on end- hosts' reliability (lifetime for instance) and constructs a shared tree called ms-DDBMSST (multiple-source Degree and Delay Bounded Maximum Stability Spanning Tree) as an overlay network that involves all the participants of the application, in a distributed manner. For a given set of nodes where some of them are senders, ms-DDBMSST is a spanning tree where the receive path stability of the entire tree is maximized while satisfying the delay-from-source constraint and degree constraint for each node. We believe that this is the first approach that defines ms-DDBMSST construction problem and presents a distributed protocol for the purpose. Our performance evaluation is based on experiments in both simulated networks and PlanetLab that strongly shows the efficiency and usefulness of the proposed protocol.
Comparison of Heart Rate Variability Signal Features Derived from Electrocardiography and Photoplethysmography in Healthy Individuals

The heart rate variability (HRV) signal is indicative of autonomic regulation of the heart rate (HR). It could be used as a noninvasive marker in monitoring the physiological state of an individual. Currently, the primary method of deriving the HRV signal is to acquire the electrocardiogram (ECG) signal, apply appropriate QRS detection algorithms to locate the R wave and its peak, find the RR intervals, and perform suitable interpolation and resampling to produce a uniformly sampled tachogram. This process could sometimes result in errors in the HRV signal due to drift, electromagnetic and biologic interference, and the complex morphology of the ECG signal. The photoplethysmographic (PPG) signal has the potential to eliminate the problems with the ECG signal to derive the HRV signal. To investigate this point, a PDA-based system was developed to simultaneously record ECG and PPG signals to facilitate accurately controlled sampling and recording durations. Two healthy young volunteers participated in this pilot study to evaluate the applicability of our approach. To improve data quality, ECG and PPG recordings were acquired three times/subject. A comparison between different features of the HRV signals derived from both methods was performed to test the validity of using PPG signals in HRV analysis. We used autoregressive (AR) modeling, Poincare' plots, cross correlation, standard deviation, arithmetic mean, skewness, kurtosis, and approximate entropy (ApEn) to derive and compare different measures from both ECG and PPG signals. This study demonstrated that our PDA-based system was a convenient and reliable means for acquisition of PPG-derived and ECG-derived HRV signals. The excellent agreement between different measures of HRV signals acquired from both methods provides potential support for the idea of using PPGs instead of ECGs in HRV signal derivation and analysis in ambulatory cardiac monitoring of healthy individuals
Targeting of the glucocorticoid hormone receptor with plasmid DNA comprising glucocorticoid response elements improves nonviral gene transfer efficiency in the lungs of mice

It has been previously demonstrated that plasmid DNA transport into the nucleus could be increased by transcription factor binding. We chose the glucocorticoid responsive element (GRE) which binds to the glucocorticoid receptor (GR), a transcription factor which is shuttled into the nucleus upon ligand binding such as dexamethasone.
Framed Discs Operads and Batalin–Vilkovisky Algebras

The framed n-discs operad fD(n) is studied as semidirect product of SO(n) and the little n-discs operad. Our equivariant recognition principle says that a grouplike space acted on by fD(n) is equivalent to the n-fold loop space on an SO(n)-space. Examples of fD(2)-spaces are nerves of ribbon braided monoidal categories. We compute the rational homology of fD(n), which produces higher Batalin-Vilkovisky algebra structures for n even. We study quadratic duality for semidirect product operads and compute the double loop space homology of a manifold as BV-algebra.
Energy and latency performance of geographic random forwarding for ad hoc and sensor networks

In this paper, we describe a novel forwarding technique based on geographical location of the nodes involved and random selection of the relaying node via contention among receivers. A collision avoidance scheme based on this idea is described in detail, and an approximate analysis is provided. The proposed scheme is compared with STEM, and is shown to perform significantly better for sufficient node density.
The nature of H I absorbers in gamma-ray burst afterglows: clues from hydrodynamic simulations

In recent work, we have shown that it is possible to link quantitatively many aspects of damped Lyman α (DLA) absorbers in the spectra of quasars to high-resolution simulations of galaxy formation. Using runs from the same series of hydrodynamic numerical studies, we consider the expected properties of intrinsic Lyman α absorbers seen in the spectra of high-redshift (z > 2) gamma-ray burst afterglows (GRB–DLAs). If GRBs are associated with the death of massive stars, their afterglows provide insights into otherwise unprobed regions of protogalactic objects, but detailed physical interpretations are currently embryonic. We find that median impact parameters (measured from the potential minimum) are approximately 1 kpc for GRBs compared with 4 kpc for quasi-stellar object–DLA (QSO–DLA). However, an equally important difference is that GRB–DLAs are predominantly associated with haloes of mass 10^(10) < M_(vir)/M_⊙ < 10^(12) , an order of magnitude larger than the hosts of QSO–DLAs. Accordingly, there are differences in the stellar properties of hosts. For instance, mean star formation rates are higher: <M(overdot)_★ ≃ 10 M_⊙ yr^(-1) for GRB–DLAs compared with <M(overdot)_★ ≃ 1 M_⊙ yr^(-1) for QSO–DLAs. Our simulations accurately predict the form of the GRB–DLA H I column density distribution, producing quantitative agreement for N_(H I) > 10^(19) cm^(−2) , but they somewhat underpredict the incidence of low column densities N_(H I_ < 10^(19) cm^(−2) . This is reflected in our estimate of the ionizing photon escape fraction, f_(esc) ≃ 1 per cent, which is lower than the observational GRB-derived escape fraction (2 per cent). Line-of-sight neutral gas metallicities predicted by our simulations (10^(−2) < Z/Z_⊙ < 1) are consistent with the modest observational constraints. Because of large internal dispersions in gas metallicities, this agreement is not significantly compromised by imposing a cut-off on the metallicity of stars able to launch GRBs (Z_★ < Z_⊙/3) , confounding claims that the observed metallicity of GRB–DLAs poses a severe challenge to current GRB models.
Discussion of paper "Factors affecting strength of elements designed using strut-and-tie models"

Keywords: Modcle de treillis / champs de contraintes ; beton ; element fini ; concrete ; finite element ; strut-and-tie model / stress fields ; Modele de treillis / champs de contraintes Reference EPFL-ARTICLE-116129View record in Web of Science Record created on 2008-01-25, modified on 2016-08-08
Optimal occupancy mapping of Virtual Networks over Elastic Optical infrastructures

One of the main challenges in Network Virtualization deals with the efficient mapping of virtual resources onto optical physical resources. This is commonly referred by Virtual Optical Network Embedding (VONE). The application of VONE for Elastic Optical Networks (EONs) has attracted the attention of industry due to the flexibility and higher transmission rates able to cope with the tremendous IP traffic demand from new applications and services. In this paper, we propose a linear model to solve the offline version of VONE over EON-based physical networks including physical layer impairments, intrinsic to the operation of EONs such as the transmission reach of robust modulation formats. Obtained results show that despite of the high complexity of the model, optimality can be reached to small and medium size instances of the problem.
The Application of Six Sigma to Integration of Computer Based Systems

This paper introduces a process for the module level integration of computer based systems. It is based on the Six Sigma Process Improvement Model, where the goal of the process is to improve the overall quality of the system under development. We also present a conceptual framework that shows how this process can be implemented as an integration solution. Finally, we provide a partial implementation of key components in the conceptual framework. Keywords—Software Quality, Six Sigma, System Integration, 3SI Process, 3SI Conceptual Framework.
Phase I trial of subcutaneous recombinant macrophage colony-stimulating factor: clinical and immunomodulatory effects.

PURPOSE Recombinant human macrophage colony-stimulating factor (rM-CSF) has been demonstrated to control the growth, differentiation, and function of mononuclear phagocytes. Preclinical studies have indicated antitumor effects, and therefore a phase I trial of rM-CSF in patients with malignancy was initiated. The toxicity and hematologic and immunologic effects were investigated. PATIENTS AND METHODS rM-CSF was administered as a subcutaneous injection on days 1 through 5 and 8 through 12. Cycles were repeated every 28 days. Cohorts of four to seven patients received rM-CSF at dose levels from 0.1 to 25.6 mg/m2/d. Forty-two patients received 88 cycles of rM-CSF. All patients had metastatic solid tumors refractory to standard therapy. RESULTS The toxicity of rM-CSF was mild. Dose-limiting toxicity included thrombocytopenia (two patients) and iritis (one patient) occurring at a dose of 25.6 mg/m2/d. Hematologic studies demonstrated dose-related monocytosis occurring routinely at doses > or = 3.2 mg/m2/d, and thrombocytopenia. Immunologic studies demonstrated enhanced secretion of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1-beta (IL-1 beta) by monocytes after in vitro stimulation with lipopolysaccharide, and increased expression of TNF-alpha mRNA at higher rM-CSF dose levels. Pharmacokinetic studies demonstrated that the systemic clearance rate of M-CSF increases during week 1 of therapy, resulting in lower blood levels of M-CSF during the second week of therapy. CONCLUSION rM-CSF can be safely administered to patients, and has biologic activity on peripheral-blood monocytes.
Software Defined Small Cell Networking under Dynamic Traffic Patterns

Software defined networking (SDN) has the potential to meet the requirements of the next generation traffic and service requirements. It is especially feasible and flexible when combining with small cell networks, which emerges into a software defined small cell networking (SDSCN) framework. SDSCN stands a chance to play a fundamental role in developing future 5G networks. It is particularly a challenging task to deploy dense small cell networks in the presence of dynamic traffic patterns and severe co-channel interference. Based on the SDSCN framework, in this paper, we propose a traffic clustering method to obtain all traffic patterns in a given area and an energy-efficient scheme to deploy and switch on/off small cell base stations (s-BSs) according to the prevailing traffic pattern. The simulation results indicate that our scheme can meet dynamic traffic demands with optimized deployment of small cells and enhance the energy efficiency of the system without compromising on the spectrum efficiency and quality-of-service (QoS) requirements. In addition, our scheme can achieve very close performance compared with the leading optimization solver CPLEX and find solutions in much less computational times than CPLEX.
Memory-Efficient Polar Decoders

Polar codes have gained a great amount of attention in the past few years, since they can provably achieve the capacity of a symmetric channel with a low-complexity encoding and decoding algorithm. As a result, polar codes have been selected as a coding scheme in the 5th generation wireless communication standard. Among different decoding schemes, successive-cancellation (SC) and SC list decoding yield good trade-off between error-correction performance and hardware implementation cost. However, both families of algorithms have large memory requirements. In this paper, we propose a set of novel techniques that aim at reducing the high-memory cost of SC-based decoders. These techniques are orthogonal to the specific decoder architecture considered, and can be applied on top of existing memory reduction techniques. We have designed and implemented different polar decoders on FPGA and also synthesized them in 65 nm TSMC CMOS technology to verify the effectiveness of the proposed memory reduction techniques. The benchmark decoders yield comparable or lower area occupation than the state of the art: the results show that the proposed methods can save up to 46% memory area occupation and 42% total area occupation compared with benchmark SC-based decoders.
Deploying Lanes for High Occupancy Vehicles in Urban Areas

Simulations and field experiments in previous works suggest that a freewayâ€™s general purpose lanes (those not dedicated to high occupancy vehicles) discharge vehicles from bottlenecks at an equal or higher average rate when one of the lanes is devoted to high occupancy vehicles than when it is not. This result was used in these previous works to develop formulae for the total discharge rate of bottlenecks, with and without dedicated lanes, as a function of the percentage of high occupancy vehicles in the traffic stream. This present paper extends these ideas by examining the effect of dedicated lanes on the density of traffic queues. We find that an underutilized dedicated lane reduces a queueâ€™s density (in vehicles per km of freeway) when the downstream flow of both high occupancy and low occupancy vehicles is the same in both scenarios and exogenously determined; e.g., as would happen if the queueâ€™s service rate is dictated by recurrent downstream congestion. A formula is given; and the reduction in density turns out to be small if the underutilization is small. Reductions in queue density without changes in bottleneck flows or traffic demand imply spatially longer queues, and this could be problematic. The paper also shows that the extra space consumed by a queue adjacent to a dedicated lane can contribute significantly to congestion, but only if heavily traveled routes that do not go through the bottleneck pass through this extra space. To quantify this effect, the paper analyzes dedicated lanes on multi-ramp freeways and beltways. Formulae are given for the changes in the people-hours and vehicle-hours of travel due to dedicated lanes both, when there is uncongested freeway space upstream of the queue for it to expand, and when there is not. The recipes are based on readily observable data and can be used to evaluate existing and planned installations of dedicated lanes. Building on these formulae, the paper finally presents qualitative principles that can be used to plan city-wide systems of both, high occupancy vehicle lanes on freeways and dedicated bus lanes on surface streets.
Resource allocation in cellular networks with moving small cells with probabilistic mobility

Passengers in city buses are possibly one of the main contributors to the increase in mobile traffic in cellular networks. Instead of each passenger accessing the cellular base station, we may deploy a small cell on the bus to serve these passengers. To reap the benefits of this deployment in the cellular network, resource allocation of the network needs to be addressed carefully. We call the small cells deployed in city buses as moving small cells. In this paper, we propose a probabilistic graph based resource allocation (PGRA) algorithm in a cellular network with moving small cells. We exploit the headway characteristics of city buses to study the interference relationship between different moving small cells. Our performance metric is the number of resource blocks used. Our performance evaluation shows an average decrease of 19.84% in the number of RBs used with moving small cells in the network as compared to a scenario without moving small cells, requiring each passenger to access the base station.