OpenRaiser/Intern-Atlas huggingface dataset:
Checkpointing with Minimal Recover in Adhocnet based TMR
Venue: arXiv cs.DC 2015
Year: 2015

This paper describes two-fold approach towards utilizing Triple Modular Redundancy (TMR) in Wireless Adhoc Network (AdocNet). A distributed checkpointing and recovery protocol is proposed. The protocol eliminates useless checkpoints and helps in selecting only dependent processes in the concerned checkpointing interval, to recover. A process starts recovery from its last checkpoint only if it finds that it is dependent (directly or indirectly) on the faulty process. The recovery protocol also prevents the occurrence of missing or orphan messages. In AdocNet, a set of three nodes (connected to each other) is considered to form a TMR set, being designated as main, primary and secondary. A main node in one set may serve as primary or secondary in another. Computation is not triplicated, but checkpoint by main is duplicated in its primary so that primary can continue if main fails. Checkpoint by primary is then duplicated in secondary if primary fails too.
Improving Efficiency of Hospitals and Healthcare Centres
Venue: arXiv cs.CY 2015
Year: 2015

The Project aims at improving the efficiency of hospitals and healthcare centres using Big Data Analytics to evaluate identified KPIs (Key Performance Indicators) of its various functions. The Dashboards designed using computer technology serves as an interactive and dynamic tool for various stakeholders, which helps in optimising performance of various functions and more so maximise the financial returns. The Project entails improving performance of patient servicing, operations and OPD departments, finance function, procurement function, HR function, etc. I developed KPIs and drilldown KPIs for various functions and assisted in designing and developing interactive Dashboards with dynamic charts.
TemplateNet for Depth-Based Object Instance Recognition
Venue: arXiv cs.CV 2015
Year: 2015

We present a novel deep architecture termed templateNet for depth based object instance recognition. Using an intermediate template layer we exploit prior knowledge of an object's shape to sparsify the feature maps. This has three advantages: (i) the network is better regularised resulting in structured filters; (ii) the sparse feature maps results in intuitive features been learnt which can be visualized as the output of the template layer and (iii) the resulting network achieves state-of-the-art performance. The network benefits from this without any additional parametrization from the template layer. We derive the weight updates needed to efficiently train this network in an end-to-end manner. We benchmark the templateNet for depth based object instance recognition using two publicly available datasets. The datasets present multiple challenges of clutter, large pose variations and similar looking distractors. Through our experiments we show that with the addition of a template layer, a depth based CNN is able to outperform existing state-of-the-art methods in the field.
A GMM-Based Stair Quality Model for Human Perceived JPEG Images
Venue: arXiv cs.MM 2015
Year: 2015

Based on the notion of just noticeable differences (JND), a stair quality function (SQF) was recently proposed to model human perception on JPEG images. Furthermore, a k-means clustering algorithm was adopted to aggregate JND data collected from multiple subjects to generate a single SQF. In this work, we propose a new method to derive the SQF using the Gaussian Mixture Model (GMM). The newly derived SQF can be interpreted as a way to characterize the mean viewer experience. Furthermore, it has a lower information criterion (BIC) value than the previous one, indicating that it offers a better model. A specific example is given to demonstrate the advantages of the new approach.
Implementing a Small Parsing Virtual Machine on Embedded Systems
Venue: arXiv cs.PL 2015
Year: 2015

PEGs are a formal grammar foundation for describing syntax, and are not hard to generate parsers with a plain recursive decent parsing. However, the large amount of C-stack consumption in the recursive parsing is not acceptable especially in resource-restricted embedded systems. Alternatively, we have attempted the machine virtualization approach to PEG-based parsing. MiniNez, our implemented virtual machine, is presented in this paper with several downsizing techniques, including instruction specialization, inline expansion and static flow analysis. As a result, the MiniNez machine achieves both a very small footprint and competitive performance to generated C parsers. We have demonstrated the experimental results by comparing on two major embedded platforms: Cortex-A7 and Intel Atom processor.
The Dune FoamGrid implementation for surface and network grids
Venue: arXiv cs.MS 2015
Year: 2015

We present FoamGrid, a new implementation of the DUNE grid interface. FoamGrid implements one- and two-dimensional grids in a physical space of arbitrary dimension, which allows for grids for curved domains. Even more, the grids are not expected to have a manifold structure, i.e., more than two elements can share a common facet. This makes FoamGrid the grid data structure of choice for simulating structures such as foams, discrete fracture networks, or network flow problems. FoamGrid implements adaptive non-conforming refinement with element parametrizations. As an additional feature it allows removal and addition of elements in an existing grid, which makes FoamGrid suitable for network growth problems. We show how to use FoamGrid, with particular attention to the extensions of the grid interface needed to handle non-manifold topology and grid growth. Three numerical examples demonstrate the possibilities offered by FoamGrid.
Community dynamics in connected time-dependent multilayer networks
Venue: arXiv cs.SI 2015
Year: 2015

Different strategies have been considered to extract information from social media about how similarly people react to the same news or event. In this context, a powerful method is offered by the application of graph techniques to the contents produced by social network users. In particular, large events typically attract enough content traffic along time to enable an analysis that explicitly models a dependence from the time dimension. Here we demonstrate how it is possible to extend the application of community detection strategies in complex networks to the case of time-dependent multilayer networks, whenever the connection between consecutive time layers is non-trivial. We apply the method to 400K Twitter post related to the Expo event held in Milan (Italy) between May and October 2015.
A Directional Diffusion Algorithm for Inpainting
Venue: arXiv cs.CV 2015
Year: 2015

The problem of inpainting involves reconstructing the missing areas of an image. Inpainting has many applications, such as reconstructing old damaged photographs or removing obfuscations from images. In this paper we present the directional diffusion algorithm for inpainting. Typical diffusion algorithms are bad at propagating edges from the image into the unknown masked regions. The directional diffusion algorithm improves on the regular diffusion algorithm by reconstructing edges more accurately. It scores better than regular diffusion when reconstructing images that are obfuscated by a text mask.
Kinetic and Cyber
Venue: arXiv cs.CY 2015
Year: 2015

We compare and contrast situation awareness in cyber warfare and in conventional, kinetic warfare. Situation awareness (SA) has a far longer history of study and applications in such areas as control of complex enterprises and in conventional warfare, than in cyber warfare. Far more is known about the SA in conventional military conflicts, or adversarial engagements, than in cyber ones. By exploring what is known about SA in conventional, also commonly referred to as kinetic, battles, we may gain insights and research directions relevant to cyber conflicts. We discuss the nature of SA in conventional (often called kinetic) conflict, review what is known about this kinetic SA (KSA), and then offer a comparison with what is currently understood regarding the cyber SA (CSA). We find that challenges and opportunities of KSA and CSA are similar or at least parallel in several important ways. With respect to similarities, in both kinetic and cyber worlds, SA strongly impacts the outcome of the mission. Also similarly, cognitive biases are found in both KSA and CSA. As an example of differences, KSA often relies on commonly accepted, widely used organizing representation - map of the physical terrain of the battlefield. No such common representation has emerged in CSA, yet.
Distributed Coordinated Beamforming for Multi-cell Multigroup Multicast Systems
Venue: arXiv cs.IT 2015
Year: 2015

This paper considers coordinated multicast beamforming in a multi-cell wireless network. Each multiantenna base station (BS) serves multiple groups of single antenna users by generating a single beam with common data per group. The aim is to minimize the sum power of BSs while satisfying user-specific SINR targets. We propose centralized and distributed multicast beamforming algorithms for multi-cell multigroup systems. The NP-hard multicast problem is tackled by approximating it as a convex problem using the standard semidefinite relaxation method. The resulting semidefinite program (SDP) can be solved via centralized processing if global channel knowledge is available. To allow a distributed implementation, the primal decomposition method is used to turn the SDP into two optimization levels. The higher level is in charge of optimizing inter-cell interference while the lower level optimizes beamformers for given inter-cell interference constraints. The distributed algorithm requires local channel knowledge at each BS and scalar information exchange between BSs. If the solution has unit rank, it is optimal for the original problem. Otherwise, the Gaussian randomization method is used to find a feasible solution. The superiority of the proposed algorithms over conventional schemes is demonstrated via numerical evaluation.
Federated Optimization:Distributed Optimization Beyond the Datacenter
Venue: arXiv cs.LG 2015
Year: 2015

We introduce a new and increasingly relevant setting for distributed optimization in machine learning, where the data defining the optimization are distributed (unevenly) over an extremely large number of \nodes, but the goal remains to train a high-quality centralized model. We refer to this setting as Federated Optimization. In this setting, communication efficiency is of utmost importance. A motivating example for federated optimization arises when we keep the training data locally on users' mobile devices rather than logging it to a data center for training. Instead, the mobile devices are used as nodes performing computation on their local data in order to update a global model. We suppose that we have an extremely large number of devices in our network, each of which has only a tiny fraction of data available totally; in particular, we expect the number of data points available locally to be much smaller than the number of devices. Additionally, since different users generate data with different patterns, we assume that no device has a representative sample of the overall distribution. We show that existing algorithms are not suitable for this setting, and propose a new algorithm which shows encouraging experimental results. This work also sets a path for future research needed in the context of federated optimization.
DataGrinder: Fast, Accurate, Fully non-Parametric Classification Approach Using 2D Convex Hulls
Venue: arXiv cs.DB 2015
Year: 2015

It has been a long time, since data mining technologies have made their ways to the field of data management. Classification is one of the most important data mining tasks for label prediction, categorization of objects into groups, advertisement and data management. In this paper, we focus on the standard classification problem which is predicting unknown labels in Euclidean space. Most efforts in Machine Learning communities are devoted to methods that use probabilistic algorithms which are heavy on Calculus and Linear Algebra. Most of these techniques have scalability issues for big data, and are hardly parallelizable if they are to maintain their high accuracies in their standard form. Sampling is a new direction for improving scalability, using many small parallel classifiers. In this paper, rather than conventional sampling methods, we focus on a discrete classification algorithm with O(n) expected running time. Our approach performs a similar task as sampling methods. However, we use column-wise sampling of data, rather than the row-wise sampling used in the literature. In either case, our algorithm is completely deterministic. Our algorithm, proposes a way of combining 2D convex hulls in order to achieve high classification accuracy as well as scalability in the same time. First, we thoroughly describe and prove our O(n) algorithm for finding the convex hull of a point set in 2D. Then, we show with experiments our classifier model built based on this idea is very competitive compared with existing sophisticated classification algorithms included in commercial statistical applications such as MATLAB.
Automated Dynamic Firmware Analysis at Scale: A Case Study on Embedded Web Interfaces
Venue: arXiv cs.CR 2015
Year: 2015

Embedded devices are becoming more widespread, interconnected, and web-enabled than ever. However, recent studies showed that these devices are far from being secure. Moreover, many embedded systems rely on web interfaces for user interaction or administration. Unfortunately, web security is known to be difficult, and therefore the web interfaces of embedded systems represent a considerable attack surface. In this paper, we present the first fully automated framework that applies dynamic firmware analysis techniques to achieve, in a scalable manner, automated vulnerability discovery within embedded firmware images. We apply our framework to study the security of embedded web interfaces running in Commercial Off-The-Shelf (COTS) embedded devices, such as routers, DSL/cable modems, VoIP phones, IP/CCTV cameras. We introduce a methodology and implement a scalable framework for discovery of vulnerabilities in embedded web interfaces regardless of the vendor, device, or architecture. To achieve this goal, our framework performs full system emulation to achieve the execution of firmware images in a software-only environment, i.e., without involving any physical embedded devices. Then, we analyze the web interfaces within the firmware using both static and dynamic tools. We also present some interesting case-studies, and discuss the main challenges associated with the dynamic analysis of firmware images and their web interfaces and network services. The observations we make in this paper shed light on an important aspect of embedded devices which was not previously studied at a large scale. We validate our framework by testing it on 1925 firmware images from 54 different vendors. We discover important vulnerabilities in 185 firmware images, affecting nearly a quarter of vendors in our dataset. These experimental results demonstrate the effectiveness of our approach.
Deep Multimodal Semantic Embeddings for Speech and Images
Venue: arXiv cs.CV 2015
Year: 2015

In this paper, we present a model which takes as input a corpus of images with relevant spoken captions and finds a correspondence between the two modalities. We employ a pair of convolutional neural networks to model visual objects and speech signals at the word level, and tie the networks together with an embedding and alignment model which learns a joint semantic space over both modalities. We evaluate our model using image search and annotation tasks on the Flickr8k dataset, which we augmented by collecting a corpus of 40,000 spoken captions using Amazon Mechanical Turk.
Channel Acquisition for Massive MIMO-OFDM with Adjustable Phase Shift Pilots
Venue: arXiv cs.IT 2015
Year: 2015

We propose adjustable phase shift pilots (APSPs) for channel acquisition in wideband massive multiple-input multiple-output (MIMO) systems employing orthogonal frequency division multiplexing (OFDM) to reduce the pilot overhead. Based on a physically motivated channel model, we first establish a relationship between channel space-frequency correlations and the channel power angle-delay spectrum in the massive antenna array regime, which reveals the channel sparsity in massive MIMO-OFDM. With this channel model, we then investigate channel acquisition, including channel estimation and channel prediction, for massive MIMO-OFDM with APSPs. We show that channel acquisition performance in terms of sum mean square error can be minimized if the user terminals' channel power distributions in the angle-delay domain can be made non-overlapping with proper phase shift scheduling. A simplified pilot phase shift scheduling algorithm is developed based on this optimal channel acquisition condition. The performance of APSPs is investigated for both one symbol and multiple symbol data models. Simulations demonstrate that the proposed APSP approach can provide substantial performance gains in terms of achievable spectral efficiency over the conventional phase shift orthogonal pilot approach in typical mobility scenarios.
Building a Decision Tree Model for Academic Advising Affairs Based on the Algorithm C 4-5
Venue: arXiv cs.OH 2015
Year: 2015

The ability to recognize students weakness and solve any problem that may confront them in timely fashion is always a target for all educational institutions. Thus, colleges and universities implement the so-called academic advising affairs. On the academic advisor relies the responsibility of solving any problem that may confront students learning progress. This paper shows how the adviser can benefit from data mining techniques, namely decision trees techniques. The C 4.5 algorithm is used as a method for building such trees. The output is evaluated based on the accuracy measure, Kappa measure, and ROC area. The difference between the registered and gained credit hours is considered as the main attribute on which advisor can rely
Kernel Methods for Accurate UWB-Based Ranging with Reduced Complexity
Venue: arXiv cs.LG 2015
Year: 2015

Accurate and robust positioning in multipath environments can enable many applications, such as search-and-rescue and asset tracking. For this problem, ultra-wideband (UWB) technology can provide the most accurate range estimates, which are required for range-based positioning. However, UWB still faces a problem with non-line-of-sight (NLOS) measurements, in which the range estimates based on time-of-arrival (TOA) will typically be positively biased. There are many techniques that address this problem, mainly based on NLOS identification and NLOS error mitigation algorithms. However, these techniques do not exploit all available information in the UWB channel impulse response. Kernel-based machine learning methods, such as Gaussian Process Regression (GPR), are able to make use of all information, but they may be too complex in their original form. In this paper, we propose novel ranging methods based on kernel principal component analysis (kPCA), in which the selected channel parameters are projected onto a nonlinear orthogonal high-dimensional space, and a subset of these projections is then used as an input for ranging. We evaluate the proposed methods using real UWB measurements obtained in a basement tunnel, and found that one of the proposed methods is able to outperform state-of-the-art, even if little training samples are available.
Tying Process Model Quality to the Modeling Process: The Impact of Structuring, Movement, and Speed
Venue: arXiv cs.SE 2015
Year: 2015

In an investigation into the process of process modeling, we examined how modeling behavior relates to the quality of the process model that emerges from that. Specifically, we considered whether (i) a modeler's structured modeling style, (ii) the frequency of moving existing objects over the modeling canvas, and (iii) the overall modeling speed is in any way connected to the ease with which the resulting process model can be understood. In this paper, we describe the exploratory study to build these three conjectures, clarify the experimental set-up and infrastructure that was used to collect data, and explain the used metrics for the various concepts to test the conjectures empirically. We discuss various implications for research and practice from the conjectures, all of which were confirmed by the experiment.
Joint Spectrum Sensing and Resource Allocation for OFDM-based Transmission with a Cognitive Relay
Venue: arXiv cs.IT 2015
Year: 2015

In this paper, we investigate the joint spectrum sensing and resource allocation problem to maximize throughput capacity of an OFDM-based cognitive radio link with a cognitive relay. By applying a cognitive relay that uses decode and forward (D&F), we achieve more reliable communications, generating less interference (by needing less transmit power) and more diversity gain. In order to account for imperfections in spectrum sensing, the proposed schemes jointly modify energy detector thresholds and allocates transmit powers to all cognitive radio (CR) subcarriers, while simultaneously assigning subcarrier pairs for secondary users (SU) and the cognitive relay. This problem is cast as a constrained optimization problem with constraints on (1) interference introduced by the SU and the cognitive relay to the PUs; (2) miss-detection and false alarm probabilities and (3) subcarrier pairing for transmission on the SU transmitter and the cognitive relay and (4) minimum Quality of Service (QoS) for each CR subcarrier. We propose one optimal and two sub-optimal schemes all of which are compared to other schemes in the literature. Simulation results show that the proposed schemes achieve significantly higher throughput than other schemes in the literature for different relay situations.
Aadhaar-Based Unified Payment Solution
Venue: arXiv cs.CR 2015
Year: 2015

In this paper, we propose to build an Aadhaar Based Unified Payment Solution. The key idea is that a virtual wallet will be linked to the Aadhaar card number of the customer. After that, any identification unique to the person and linked with the Aadhaar card, be it something the person knows like secret Internet-banking password, be it something s/he carries like debit card/ credit card, something s/he owns like fingerprints, voice, email-id or somewhere s/he is like house or office address, can be used for money transfer from the sender's Aadhaar card linked virtual wallet to the receiver's Aadhaar card linked virtual wallet, whose any unique ID is known to the sender. If the sender knows the receiver's email-id, s/he can transfer money to his/ her Aadhaar card linked virtual wallet using the email-id. And, if the sender knows receiver's mobile number but not email-id, s/he can use the mobile number to transfer the money to his/ her Aadhaar card linked virtual wallet. And so on.
Formal Specification and Verification of Fully Asynchronous Implementations of the Data Encryption Standard
Venue: arXiv cs.LO 2015
Year: 2015

This paper presents two formal models of the Data Encryption Standard (DES), a first using the international standard LOTOS, and a second using the more recent process calculus LNT. Both models encode the DES in the style of asynchronous circuits, i.e., the data-flow blocks of the DES algorithm are represented by processes communicating via rendezvous. To ensure correctness of the models, several techniques have been applied, including model checking, equivalence checking, and comparing the results produced by a prototype automatically generated from the formal model with those of existing implementations of the DES. The complete code of the models is provided as appendices and also available on the website of the CADP verification toolbox.