OpenRaiser/Intern-Atlas huggingface dataset:
CRISTAL : A Practical Study in Designing Systems to Cope with Change
Venue: arXiv cs.SE 2014
Year: 2014

Software engineers frequently face the challenge of developing systems whose requirements are likely to change in order to adapt to organizational reconfigurations or other external pressures. Evolving requirements present difficulties, especially in environments in which business agility demands shorter development times and responsive prototyping. This paper uses a study from CERN in Geneva to address these research questions by employing a description-driven approach that is responsive to changes in user requirements and that facilitates dynamic system reconfiguration. The study describes how handling descriptions of objects in practice alongside their instances (making the objects self-describing) can mediate the effects of evolving user requirements on system development. This paper reports on and draws lessons from the practical use of a description-driven system over time. It also identifies lessons that can be learned from adopting such a self-describing description-driven approach in future software development.
Bandits with concave rewards and convex knapsacks
Venue: arXiv cs.LG 2014
Year: 2014

In this paper, we consider a very general model for exploration-exploitation tradeoff which allows arbitrary concave rewards and convex constraints on the decisions across time, in addition to the customary limitation on the time horizon. This model subsumes the classic multi-armed bandit (MAB) model, and the Bandits with Knapsacks (BwK) model of Badanidiyuru et al.[2013]. We also consider an extension of this model to allow linear contexts, similar to the linear contextual extension of the MAB model. We demonstrate that a natural and simple extension of the UCB family of algorithms for MAB provides a polynomial time algorithm that has near-optimal regret guarantees for this substantially more general model, and matches the bounds provided by Badanidiyuru et al.[2013] for the special case of BwK, which is quite surprising. We also provide computationally more efficient algorithms by establishing interesting connections between this problem and other well studied problems/algorithms such as the Blackwell approachability problem, online convex optimization, and the Frank-Wolfe technique for convex optimization. We give examples of several concrete applications, where this more general model of bandits allows for richer and/or more efficient formulations of the problem.
Data Management Challenges in Paediatric Information Systems
Venue: arXiv cs.DB 2014
Year: 2014

There is a compelling demand for the data integration and exploitation of heterogeneous biomedical information for improved clinical practice, medical research, and personalised healthcare across the EU. The area of paediatric information integration is particularly challenging since the patients physiology changes with growth and different aspects of health being regularly monitored over extended periods of time. Paediatricians require access to heterogeneous data sets, often collected in different locations with different apparatus and over extended timescales. Using a Grid platform originally developed for physics at CERN and a novel integrated semantic data model the Health-e-Child project has developed an integrated healthcare platform for European paediatrics, providing seamless integration of traditional and emerging sources of biomedical data. The long-term goal of the project was to provide uninhibited access to universal biomedical knowledge repositories for personalised and preventive healthcare, large-scale information-based biomedical research and training, and informed policy making. The project built a Grid-enabled european network of leading clinical centres that can share and annotate paediatric data, can validate systems clinically, and diffuse clinical excellence across Europe by setting up new technologies, clinical workflows, and standards. The Health-e-Child project highlights data management challenges for the future of European paediatric healthcare and is the subject of this chapter.
Information Filtering via Balanced Diffusion on Bipartite Networks
Venue: arXiv cs.IR 2014
Year: 2014

Recent decade has witnessed the increasing popularity of recommender systems, which help users acquire relevant commodities and services from overwhelming resources on Internet. Some simple physical diffusion processes have been used to design effective recommendation algorithms for user-object bipartite networks, typically mass diffusion (MD) and heat conduction (HC) algorithms which have different advantages respectively on accuracy and diversity. In this paper, we investigate the effect of weight assignment in the hybrid of MD and HC, and find that a new hybrid algorithm of MD and HC with balanced weights will achieve the optimal recommendation results, we name it balanced diffusion (BD) algorithm. Numerical experiments on three benchmark data sets, MovieLens, Netflix and RateYourMusic (RYM), show that the performance of BD algorithm outperforms the existing diffusion-based methods on the three important recommendation metrics, accuracy, diversity and novelty. Specifically, it can not only provide accurately recommendation results, but also yield higher diversity and novelty in recommendations by accurately recommending unpopular objects.
A Novel Scheme for Intelligent Recognition of Pornographic Images
Venue: arXiv cs.CV 2014
Year: 2014

Harmful contents are rising in internet day by day and this motivates the essence of more research in fast and reliable obscene and immoral material filtering. Pornographic image recognition is an important component in each filtering system. In this paper, a new approach for detecting pornographic images is introduced. In this approach, two new features are suggested. These two features in combination with other simple traditional features provide decent difference between porn and non-porn images. In addition, we applied fuzzy integral based information fusion to combine MLP (Multi-Layer Perceptron) and NF (Neuro-Fuzzy) outputs. To test the proposed method, performance of system was evaluated over 18354 download images from internet. The attained precision was 93% in TP and 8% in FP on training dataset, and 87% and 5.5% on test dataset. Achieved results verify the performance of proposed system versus other related works.
Deconvolution Using Projections Onto The Epigraph Set of a Convex Cost Function
Venue: arXiv cs.DS 2014
Year: 2014

A new deconvolution algorithm based on orthogonal projections onto the epigraph set of a convex cost function is presented. In this algorithm, the dimension of the minimization problem is lifted by one and sets corresponding to the cost function are defined. As the utilized cost function is a convex function in $R^N$, the corresponding epigraph set is also a convex set in $R^{N+1}$. The deconvolution algorithm starts with an arbitrary initial estimate in $R^{N+1}$. At each step of the iterative algorithm, first deconvolution projections are performed onto the epigraphs, later an orthogonal projection is performed onto one of the constraint sets associated with the cost function in a sequential manner. The method provides globally optimal solutions for total-variation, $\ell_1$, $\ell_2$, and entropic cost functions.
Mathematical Modelling of Energy Wastage in Absence of Levelling and Sectoring in Wireless Sensor Networks
Venue: arXiv cs.IT 2014
Year: 2014

In this paper, we quantitatively (mathematically) reason the energy savings achieved by the Leveling and Sectoring protocol. Due to the energy constraints on the sensor nodes (in terms of supply of energy) energy awareness has become crucial in networking protocol stack. The understanding of routing protocols along with energy awareness in a network would help in energy opti-mization with efficient routing .We provide analytical modelling of the energy wastage in the absence of Leveling and Sectoring protocol by considering the network in the form of binary tree, nested tree and Q-ary tree. The simulation results reflect the energy wastage in the absence of Levelling and Sectoring based hybrid protocol.
Compound Multiple Access Channel with Confidential Messages
Venue: arXiv cs.IT 2014
Year: 2014

In this paper, we study the problem of secret communication over a Compound Multiple Access Channel (MAC). In this channel, we assume that one of the transmitted messages is confidential that is only decoded by its corresponding receiver and kept secret from the other receiver. For this proposed setting (compound MAC with confidential messages), we derive general inner and outer bounds on the secrecy capacity region. Also, as examples, we investigate 'Less noisy' and 'Gaussian' versions of this channel, and extend the results of the discrete memoryless version to these cases. Moreover, providing numerical examples for the Gaussian case, we illustrate the comparison between achievable rate regions of compound MAC and compound MAC with confidential messages.
On the Vector Broadcast Channel with Alternating CSIT: A Topological Perspective
Venue: arXiv cs.IT 2014
Year: 2014

In many wireless networks, link strengths are affected by many topological factors such as different distances, shadowing and inter-cell interference, thus resulting in some links being generally stronger than other links. From an information theoretic point of view, accounting for such topological aspects has remained largely unexplored, despite strong indications that such aspects can crucially affect transceiver and feedback design, as well as the overall performance. The work here takes a step in exploring this interplay between topology, feedback and performance. This is done for the two user broadcast channel with random fading, in the presence of a simple two-state topological setting of statistically strong vs. weaker links, and in the presence of a practical ternary feedback setting of alternating channel state information at the transmitter (alternating CSIT) where for each channel realization, this CSIT can be perfect, delayed, or not available. In this setting, the work derives generalized degrees-of-freedom bounds and exact expressions, that capture performance as a function of feedback statistics and topology statistics. The results are based on novel topological signal management (TSM) schemes that account for topology in order to fully utilize feedback. This is achieved for different classes of feedback mechanisms of practical importance, from which we identify specific feedback mechanisms that are best suited for different topologies. This approach offers further insight on how to split the effort --- of channel learning and feeding back CSIT --- for the strong versus for the weaker link. Further intuition is provided on the possible gains from topological spatio-temporal diversity, where topology changes in time and across users.
A Testbed for Cross-Dataset Analysis
Venue: arXiv cs.CV 2014
Year: 2014

Since its beginning visual recognition research has tried to capture the huge variability of the visual world in several image collections. The number of available datasets is still progressively growing together with the amount of samples per object category. However, this trend does not correspond directly to an increasing in the generalization capabilities of the developed recognition systems. Each collection tends to have its specific characteristics and to cover just some aspects of the visual world: these biases often narrow the effect of the methods defined and tested separately over each image set. Our work makes a first step towards the analysis of the dataset bias problem on a large scale. We organize twelve existing databases in a unique corpus and we present the visual community with a useful feature repository for future research.
A generalization of extension complexity that captures $P$
Venue: arXiv cs.CC 2014
Year: 2014

In this paper we propose a generalization of the extension complexity of a polyhedron $Q$. On the one hand it is general enough so that all problems in $P$ can be formulated as linear programs with polynomial size extension complexity. On the other hand it still allows non-polynomial lower bounds to be proved for $NP$-hard problems independently of whether or not $P=NP$. The generalization, called $H$-free extension complexity, allows for a set of valid inequalities $H$ to be excluded in computing the extension complexity of $Q$. We give results on the $H$-free extension complexity of hard matching problems (when $H$ are the odd set inequalities) and the traveling salesman problem (when $H$ are the subtour elimination constraints).
Bounded-Angle Spanning Tree: Modeling Networks with Angular Constraints
Venue: arXiv cs.CG 2014
Year: 2014

We introduce a new structure for a set of points in the plane and an angle $α$, which is similar in flavor to a bounded-degree MST. We name this structure $α$-MST. Let $P$ be a set of points in the plane and let $0 < α\le 2π$ be an angle. An $α$-ST of $P$ is a spanning tree of the complete Euclidean graph induced by $P$, with the additional property that for each point $p \in P$, the smallest angle around $p$ containing all the edges adjacent to $p$ is at most $α$. An $α$-MST of $P$ is then an $α$-ST of $P$ of minimum weight. For $α< π/3$, an $α$-ST does not always exist, and, for $α\ge π/3$, it always exists. In this paper, we study the problem of computing an $α$-MST for several common values of $α$. Motivated by wireless networks, we formulate the problem in terms of directional antennas. With each point $p \in P$, we associate a wedge $W_p$ of angle $α$ and apex $p$. The goal is to assign an orientation and a radius $r_p$ to each wedge $W_p$, such that the resulting graph is connected and its MST is an $α$-MST. (We draw an edge between $p$ and $q$ if $p \in W_q$, $q \in W_p$, and $|pq| \le r_p, r_q$.) Unsurprisingly, the problem of computing an $α$-MST is NP-hard, at least for $α=π$ and $α=2π/3$. We present constant-factor approximation algorithms for $α= π/2, 2π/3, π$. One of our major results is a surprising theorem for $α= 2π/3$, which, besides being interesting from a geometric point of view, has important applications. For example, the theorem guarantees that given any set $P$ of $3n$ points in the plane and any partitioning of the points into $n$ triplets, one can orient the wedges of each triplet {\em independently}, such that the graph induced by $P$ is connected. We apply the theorem to the {\em antenna conversion} problem.
The Role of Visibility in Pursuit / Evasion Games
Venue: arXiv cs.DM 2014
Year: 2014

The cops-and-robber (CR) game has been used in mobile robotics as a discretized model (played on a graph G) of pursuit/evasion problems. The "classic" CR version is a perfect information game: the cops' (pursuer's) location is always known to the robber (evader) and vice versa. Many variants of the classic game can be defined: the robber can be invisible and also the robber can be either adversarial (tries to avoid capture) or drunk (performs a random walk). Furthermore, the cops and robber can reside in either nodes or edges of G. Several of these variants are relevant as models or robotic pursuit / evasion. In this paper, we first define carefully several of the variants mentioned above and related quantities such as the cop number and the capture time. Then we introduce and study the cost of visibility (COV), a quantitative measure of the increase in difficulty (from the cops' point of view) when the robber is invisible. In addition to our theoretical results, we present algorithms which can be used to compute capture times and COV of graphs which are analytically intractable. Finally, we present the results of applying these algorithms to the numerical computation of COV.
Towards Provenance and Traceability in CRISTAL for HEP
Venue: arXiv cs.SE 2014
Year: 2014

This paper discusses the CRISTAL object lifecycle management system and its use in provenance data management and the traceability of system events. This software was initially used to capture the construction and calibration of the CMS ECAL detector at CERN for later use by physicists in their data analysis. Some further uses of CRISTAL in different projects (CMS, neuGRID and N4U) are presented as examples of its flexible data model. From these examples, applications are drawn for the High Energy Physics domain and some initial ideas for its use in data preservation HEP are outlined in detail in this paper. Currently investigations are underway to gauge the feasibility of using the N4U Analysis Service or a derivative of it to address the requirements of data and analysis logging and provenance capture within the HEP long term data analysis environment.
Mobile GIS and Open Source Platform Based on Android: Technology for System Pregnant Women
Venue: arXiv cs.CY 2014
Year: 2014

The statistic of World Health Organization shows at one year about 287000 women died most of them during and following pregnancy and childbirth in Africa and south Asia. This paper suggests system for serving pregnant women using open source based on Android technology, the proposed system works based on mobile GIS to select closest care centre or hospital maternity on Google map for the pregnant woman, which completed an online registration by sending SMS via GPRS network (or internet) contains her name and phone number and region (Longitude and Latitude) and other required information the server will save the information in server database then find the closest care centre and call her for first review at the selected care centre, the proposed system allowed the pregnant women from her location (home, market, etc) can send a help request in emergency cases (via SMS by click one button) contains the ID for this pregnant woman, and her coordinates (Longitude and Latitude) via GPRS network, then the server will locate the pregnant on Google map and retrieve the pregnant information from the database. This information will be used by the server to send succoring to pregnant woman at her location and at the same time notify the nearest hospital and moreover, the server will send SMS over IP to inform her husband and the hospital doctors. Implement and applied this proposed system of pregnant women shows more effective cost than other systems because it works in economic mode (SMS), and the services of proposed system are flexible (open source platform) as well as rapidly (mobile GIS based on Android) achieved locally registration, succoring in emergency cases, change the review date of pregnant woman, addition to different types of advising according to pregnancy. Index Terms: Build-in GPS; GPRS; Mobile GIS; SoIP; Open Source; Google Maps API ; Android Technology
Deconstruction of compound objects from image sets
Venue: arXiv cs.CV 2014
Year: 2014

We propose a method to recover the structure of a compound object from multiple silhouettes. Structure is expressed as a collection of 3D primitives chosen from a pre-defined library, each with an associated pose. This has several advantages over a volume or mesh representation both for estimation and the utility of the recovered model. The main challenge in recovering such a model is the combinatorial number of possible arrangements of parts. We address this issue by exploiting the sparse nature of the problem, and show that our method scales to objects constructed from large libraries of parts.
A Novel User Pairing Scheme for Functional Decode-and-Forward Multi-way Relay Network
Venue: arXiv cs.IT 2014
Year: 2014

In this paper, we consider a functional decode and forward (FDF) multi-way relay network (MWRN) where a common user facilitates each user in the network to obtain messages from all other users. We propose a novel user pairing scheme, which is based on the principle of selecting a common user with the best average channel gain. This allows the user with the best channel conditions to contribute to the overall system performance. Assuming lattice code based transmissions, we derive upper bounds on the average common rate and the average sum rate with the proposed pairing scheme. Considering M-ary quadrature amplitude modulation with square constellation as a special case of lattice code transmission, we derive asymptotic average symbol error rate (SER) of the MWRN. We show that in terms of the achievable rates, the proposed pairing scheme outperforms the existing pairing schemes under a wide range of channel scenarios. The proposed pairing scheme also has lower average SER compared to existing schemes. We show that overall, the MWRN performance with the proposed pairing scheme is more robust, compared to existing pairing schemes, especially under worst case channel conditions when majority of users have poor average channel gains.
Coverage and Rate Analysis for Millimeter Wave Cellular Networks
Venue: arXiv cs.IT 2014
Year: 2014

Millimeter wave (mmWave) holds promise as a carrier frequency for fifth generation cellular networks. Because mmWave signals are sensitive to blockage, prior models for cellular networks operated in the ultra high frequency (UHF) band do not apply to analyze mmWave cellular networks directly. Leveraging concepts from stochastic geometry, this paper proposes a general framework to evaluate the coverage and rate performance in mmWave cellular networks. Using a distance-dependent line-of-site (LOS) probability function, the locations of the LOS and non-LOS base stations are modeled as two independent non-homogeneous Poisson point processes, to which different path loss laws are applied. Based on the proposed framework, expressions for the signal-to-noise-and-interference ratio (SINR) and rate coverage probability are derived. The mmWave coverage and rate performance are examined as a function of the antenna geometry and base station density. The case of dense networks is further analyzed by applying a simplified system model, in which the LOS region of a user is approximated as a fixed LOS ball. The results show that dense mmWave networks can achieve comparable coverage and much higher data rates than conventional UHF cellular systems, despite the presence of blockages. The results suggest that the cell size to achieve the optimal SINR scales with the average size of the area that is LOS to a user.