OpenRaiser/Intern-Atlas huggingface dataset:
VoID-graph: Visualize Linked Datasets on the Web
Venue: arXiv cs.DB 2014
Year: 2014

The Linked Open Data (LOD) cloud diagram is a picture that helps us grasp the contents and the links of globally available data sets. Such diagram has been a powerful dissemination method for the Linked Data movement, allowing people to glance at the size and structure of this distributed, interconnected database. However, generating such image for third-party datasets can be a quite complex task as it requires the installation and understanding of a variety of tools which are not easy to setup. In this paper we present VoID-graph (http://lmatteis.github.io/void-graph/), a standalone web-tool that, given a VoID description, can visualize a diagram similar to the LOD cloud. It is novel because the diagram is autonomously shaped from VoID descriptions directly within a Web-browser, which doesn't require any server cooperation. This makes it not only easy to use, as no installation or configuration is required, but also makes it more sustainable, as it is built using Open Web standards such as JavaScript and SVG.
Zeros of Networked Systems with Time-invariant Interconnections
Venue: arXiv cs.SY 2014
Year: 2014

This paper studies zeros of networked linear systems with time-invariant interconnection topology. While the characterization of zeros is given for both heterogeneous and homogeneous networks, homogeneous networks are explored in greater detail. In the current paper, for homogeneous networks with time-invariant interconnection dynamics, it is illustrated how the zeros of each individual agent's system description and zeros definable from the interconnection dynamics contribute to generating zeros of the whole network. We also demonstrate how zeros of networked systems and those of their associated blocked versions are related.
Joint Bi-Directional Training of Nonlinear Precoders and Receivers in Cellular Networks
Venue: arXiv cs.IT 2014
Year: 2014

Joint optimization of nonlinear precoders and receive filters is studied for both the uplink and downlink in a cellular system. For the uplink, the base transceiver station (BTS) receiver implements successive interference cancellation, and for the downlink, the BTS station pre-compensates for the interference with Tomlinson-Harashima precoding (THP). Convergence of alternating optimization of receivers and transmitters in a single cell is established when filters are updated according to a minimum mean squared error (MMSE) criterion, subject to appropriate power constraints. Adaptive algorithms are then introduced for updating the precoders and receivers in the absence of channel state information, assuming time-division duplex transmissions with channel reciprocity. Instead of estimating the channels, the filters are directly estimated according to a least squares criterion via bi-directional training: Uplink pilots are used to update the feedforward and feedback filters, which are then used as interference pre-compensation filters for downlink training of the mobile receivers. Numerical results show that nonlinear filters can provide substantial gains relative to linear filters with limited forward-backward iterations.
Factors Influencing the Quality of the User Experience in Ubiquitous Recommender Systems
Venue: arXiv cs.HC 2014
Year: 2014

The use of mobile devices and the rapid growth of the internet and networking infrastructure has brought the necessity of using Ubiquitous recommender systems. However in mobile devices there are different factors that need to be considered in order to get more useful recommendations and increase the quality of the user experience. This paper gives an overview of the factors related to the quality and proposes a new hybrid recommendation model.
Comment on "Ensemble Projection for Semi-supervised Image Classification"
Venue: arXiv cs.CV 2014
Year: 2014

In a series of papers by Dai and colleagues [1,2], a feature map (or kernel) was introduced for semi- and unsupervised learning. This feature map is build from the output of an ensemble of classifiers trained without using the ground-truth class labels. In this critique, we analyze the latest version of this series of papers, which is called Ensemble Projections [2]. We show that the results reported in [2] were not well conducted, and that Ensemble Projections performs poorly for semi-supervised learning.
A Privacy-Preserving Electronic Payment System for DRM
Venue: arXiv cs.CR 2014
Year: 2014

One of major considerations in an online business is customer privacy. Consumers are not interested in being monitored and identified by sellers. Some solutions are proposed to hide selection of the customer but in the payment phase, there will be a leakage of information as online shopper can infer some information about customer's preference due to the price, which is paid by customer. This is a big threat to customer privacy. Our solution to this problem consists of a number of one-unit payment steps that cannot be linked to each other or to customer's identity. At the end of purchase, content provider will receive appropriate amount of money while customer will acquire a valid license anonymously. Content provider will not be able to gain any information about the customer or the content that is purchased. In addition, a dispute resolution scheme is presented for cases of conflict between customer and content provider. A series of analyses on the security, complexity and DRM requirements are presented which indicate security and practicality of our scheme.
Impact of Secondary User Communication on Security Communication of Primary User
Venue: arXiv cs.CR 2014
Year: 2014

Recently, spectrum sharing has been considered as a promising solution to improve the spectrum utilization. It however may be vulnerable to security problems as the primary and secondary network access the same resource. Therefore, in this paper, we focus on the performance analysis of a cognitive radio network in the presence of an eavesdropper (EAV) who illegally listens to the primary user (PU) communication in which the transmit power of the secondary transmitter (SU-Tx) is subject to the joint constraint of peak transmit power of the SU-Tx and outage probability of the PU. Accordingly, an adaptive transmit power policy and an analytical expression of symbol error probability are derived for the SU. Most importantly, security evaluations of primary network in terms of the probability of existence of non-zero secrecy capacity and outage probability of secrecy capacity are obtained. Numerical results reveal a fact that the security of the primary network does not only depends on the channel mean powers between primary and secondary networks, but also strongly depends on the channel condition of the SU-Tx to EAV link and transmit power policy of the SU-Tx.
Software-Defined and Virtualized Future Mobile and Wireless Networks: A Survey
Venue: arXiv cs.NI 2014
Year: 2014

With the proliferation of mobile demands and increasingly multifarious services and applications, mobile Internet has been an irreversible trend. Unfortunately, the current mobile and wireless network (MWN) faces a series of pressing challenges caused by the inherent design. In this paper, we extend two latest and promising innovations of Internet, software-defined networking and network virtualization, to mobile and wireless scenarios. We first describe the challenges and expectations of MWN, and analyze the opportunities provided by the software-defined wireless network (SDWN) and wireless network virtualization (WNV). Then, this paper focuses on SDWN and WNV by presenting the main ideas, advantages, ongoing researches and key technologies, and open issues respectively. Moreover, we interpret that these two technologies highly complement each other, and further investigate efficient joint design between them. This paper confirms that SDWN and WNV may efficiently address the crucial challenges of MWN and significantly benefit the future mobile and wireless network.
On $k$-Gons and $k$-Holes in Point Sets
Venue: arXiv cs.DM 2014
Year: 2014

We consider a variation of the classical Erdős-Szekeres problems on the existence and number of convex $k$-gons and $k$-holes (empty $k$-gons) in a set of $n$ points in the plane. Allowing the $k$-gons to be non-convex, we show bounds and structural results on maximizing and minimizing their numbers. Most noteworthy, for any $k$ and sufficiently large $n$, we give a quadratic lower bound for the number of $k$-holes, and show that this number is maximized by sets in convex position.
A Plug&Play P300 BCI Using Information Geometry
Venue: arXiv cs.LG 2014
Year: 2014

This paper presents a new classification methods for Event Related Potentials (ERP) based on an Information geometry framework. Through a new estimation of covariance matrices, this work extend the use of Riemannian geometry, which was previously limited to SMR-based BCI, to the problem of classification of ERPs. As compared to the state-of-the-art, this new method increases performance, reduces the number of data needed for the calibration and features good generalisation across sessions and subjects. This method is illustrated on data recorded with the P300-based game brain invaders. Finally, an online and adaptive implementation is described, where the BCI is initialized with generic parameters derived from a database and continuously adapt to the individual, allowing the user to play the game without any calibration while keeping a high accuracy.
Computerized Multi Microphone Test System
Venue: arXiv cs.SD 2014
Year: 2014

An acoustic testing approach based on the concept of a microphone sensor surrounding the product under test is proposed. Microphone signals are processed simultaneously by a test system computer, according to the objective of the test. The spatial and frequency domain selectivity features of this method are examined. Sound-spatial visualization algorithm is observed. A test system design based on the concept of a microphone surrounding the tested product has the potential to improve distortion measurement accuracy.
Through the Frosted Glass: Security Problems in a Translucent UI
Venue: arXiv cs.HC 2014
Year: 2014

Translucency is now a common design element in at least one popular mobile operating system. This raises security concerns as it can make it harder for users to correctly identify and interpret trusted interaction elements. In this paper, we demonstrate this security problem using the example of the Safari browser in the latest iOS version on Apple tablets and phones (iOS7), and discuss technical challenges of an attack as well as solutions to these challenges. We conclude with a survey-based user study, where we seek to quantify the security impact, and find that further investigation is warranted.
Outage Probability of Energy Harvesting Relay-aided Cooperative Networks Over Rayleigh Fading Channel
Venue: arXiv cs.IT 2014
Year: 2014

Energy harvesting technique is a potential way for relay node energy supply in cooperative networks in terms of deployment flexibility and maintain charge reduction. Unlike traditional power source, relay node in this case may run out of energy with certain probability, which can degrade the benefit from relay-aided cooperative transmission. In this paper, we concentrate on the outage behavior of cooperative networks aided by energy harvesting relay node in slow fading channel, and attempt to derive the closed-form expression of outage probability of proposed cooperative protocol. Compared with traditional direct transmission protocol, two conclusions are derived: 1) the diversity gain cannot be increased excepting the extreme case that energy-exhausted probability is zero; 2) a multiplicative gain for improving system performance can be obtained in terms of minimizing outage probability.
Team Behavior in Interactive Dynamic Influence Diagrams with Applications to Ad Hoc Teams
Venue: arXiv cs.MA 2014
Year: 2014

Planning for ad hoc teamwork is challenging because it involves agents collaborating without any prior coordination or communication. The focus is on principled methods for a single agent to cooperate with others. This motivates investigating the ad hoc teamwork problem in the context of individual decision making frameworks. However, individual decision making in multiagent settings faces the task of having to reason about other agents' actions, which in turn involves reasoning about others. An established approximation that operationalizes this approach is to bound the infinite nesting from below by introducing level 0 models. We show that a consequence of the finitely-nested modeling is that we may not obtain optimal team solutions in cooperative settings. We address this limitation by including models at level 0 whose solutions involve learning. We demonstrate that the learning integrated into planning in the context of interactive dynamic influence diagrams facilitates optimal team behavior, and is applicable to ad hoc teamwork.
An Interim Summary on Semantic Model Differencing
Venue: arXiv cs.SE 2014
Year: 2014

This position paper provides an interim summary on the goals and current state of our ongoing research project on semantic model differencing for software evolution. We describe the basics of semantic model differencing, give two examples from our recent work, and discuss future challenges in taking full advantage of the potential of semantic differencing techniques in the context of models' evolution.
The Energy Navigator - A Web-Platform for Performance Design and Management
Venue: arXiv cs.SE 2014
Year: 2014

Over the last three decades comprehensive research has been carried out trying to improve commissioning processes with powerful modeling tools and methodologies for data analysis and visualization. Typically addressed application scenarios are facilities management, contracting, special consulting services and measurement & verification as part of a certification process. The results are all but convincing: Monitoring of building operation has so far not become a regular service for buildings. We have identified a lack of process integration as a significant barrier for market success. Most methodologies have so far caused additional initial invest and transaction cost: they added new services instead of improving existing ones. The Energy Navigator, developed by synavision GmbH in cooperation with leading research institutes of the Technical University Braunschweig and the RWTH Aachen University, presents a new methodology with several new approaches. Its software platform uses state graphs and a domain specific language to describe building functions offering an alternative to the software that is so far most widely used for this task: Microsoft Word. The Energy Navigators so called Active Functional Specification (AFS) is used for the technical specification of building services in the design phase. After construction it is completed by the supplier of the BMS (Building Management System) with the relevant sensors data as documentation of his service. Operation data can then automatically be checked for initial and continuous commissioning on whether it meets the criteria of the specification.
A New Algorithm for Solving Ring-LPN with a Reducible Polynomial
Venue: arXiv cs.CR 2014
Year: 2014

The LPN (Learning Parity with Noise) problem has recently proved to be of great importance in cryptology. A special and very useful case is the RING-LPN problem, which typically provides improved efficiency in the constructed cryptographic primitive. We present a new algorithm for solving the RING-LPN problem in the case when the polynomial used is reducible. It greatly outperforms previous algorithms for solving this problem. Using the algorithm, we can break the Lapin authentication protocol for the proposed instance using a reducible polynomial, in about 2^70 bit operations.
Population spatialization and synthesis with open data
Venue: arXiv cs.OH 2014
Year: 2014

Individuals together with their locations & attributes are essential to feed micro-level applied urban models (for example, spatial micro-simulation and agent-based modeling) for policy evaluation. Existed studies on population spatialization and population synthesis are generally separated. In developing countries like China, population distribution in a fine scale, as the input for population synthesis, is not universally available. With the open-government initiatives in China and the emerging Web 2.0 techniques, more and more open data are becoming achievable. In this paper, we propose an automatic process using open data for population spatialization and synthesis. Specifically, the road network in OpenStreetMap is used to identify and delineate parcel geometries, while crowd-sourced POIs are gathered to infer urban parcels with a vector cellular automata model. Housing-related online Check-in records are then applied to distinguish residential parcels from all of the identified urban parcels. Finally the published census data, in which the sub-district level of attributes distribution and relationships are available, is used for synthesizing population attributes with a previously developed tool Agenter (Long and Shen, 2013). The results are validated with ground truth manually-prepared dataset by planners from Beijing Institute of City Planning.
Comparing Stochastic Differential Equations and Agent-Based Modelling and Simulation for Early-stage Cancer
Venue: arXiv cs.MA 2014
Year: 2014

There is great potential to be explored regarding the use of agent-based modelling and simulation as an alternative paradigm to investigate early-stage cancer interactions with the immune system. It does not suffer from some limitations of ordinary differential equation models, such as the lack of stochasticity, representation of individual behaviours rather than aggregates and individual memory. In this paper we investigate the potential contribution of agent-based modelling and simulation when contrasted with stochastic versions of ODE models using early-stage cancer examples. We seek answers to the following questions: (1) Does this new stochastic formulation produce similar results to the agent-based version? (2) Can these methods be used interchangeably? (3) Do agent-based models outcomes reveal any benefit when compared to the Gillespie results? To answer these research questions we investigate three well-established mathematical models describing interactions between tumour cells and immune elements. These case studies were re-conceptualised under an agent-based perspective and also converted to the Gillespie algorithm formulation. Our interest in this work, therefore, is to establish a methodological discussion regarding the usability of different simulation approaches, rather than provide further biological insights into the investigated case studies. Our results show that it is possible to obtain equivalent models that implement the same mechanisms; however, the incapacity of the Gillespie algorithm to retain individual memory of past events affects the similarity of some results. Furthermore, the emergent behaviour of ABMS produces extra patters of behaviour in the system, which was not obtained by the Gillespie algorithm.
Secure Cloud Computing through Homomorphic Encryption
Venue: arXiv cs.CR 2014
Year: 2014

Go to the cloud, has always been the dream of man. Cloud Computing offers a number of benefits and services to its customers who pay the use of hardware and software resources (servers hosted in data centers, applications, software...) on demand which they can access via internet without the need of expensive computers or a large storage system capacity and without paying any equipment maintenance fees. But these cloud providers must provide guarantees on the protection of privacy and sensitive data stored in their data centers shared between multiple clients using the concept of virtualization.
Extended Delivery Time Analysis for Non-work-preserving Packet Transmission in Cognitive Environment
Venue: arXiv cs.IT 2014
Year: 2014

Cognitive radio transceiver can opportunistically access the underutilized spectrum resource of primary systems for new wireless services. With interweave cognitive implementation, the secondary transmission may be interrupted by the primary user's transmission. To facilitate the packet delay analysis of such secondary transmission, we study the resulting extended delivery time that includes both transmission time and waiting time. In particular, we derive the exact distribution function of extended delivery time of a fixed-size secondary packet with non-work-preserving strategy i.e. interrupted packets will be retransmitted. Both continuous sensing and periodic sensing with and without missed detection cases are considered. Selected numerical and simulation results are presented for verifying the mathematical formulation. Finally, we apply the results to secondary queuing analysis with a generalized M/G/1 queue set-up. The analytical results will greatly facilitate the design of the secondary system for particular target application.
Visual Passwords Using Automatic Lip Reading
Venue: arXiv cs.CV 2014
Year: 2014

This paper presents a visual passwords system to increase security. The system depends mainly on recognizing the speaker using the visual speech signal alone. The proposed scheme works in two stages: setting the visual password stage and the verification stage. At the setting stage the visual passwords system request the user to utter a selected password, a video recording of the user face is captured, and processed by a special words-based VSR system which extracts a sequence of feature vectors. In the verification stage, the same procedure is executed, the features will be sent to be compared with the stored visual password. The proposed scheme has been evaluated using a video database of 20 different speakers (10 females and 10 males), and 15 more males in another video database with different experiment sets. The evaluation has proved the system feasibility, with average error rate in the range of 7.63% to 20.51% at the worst tested scenario, and therefore, has potential to be a practical approach with the support of other conventional authentication methods such as the use of usernames and passwords.
Towards information-centric WSN simulations
Venue: arXiv cs.NI 2014
Year: 2014

In pursuance of integrating Wireless Sensor Networks (WSNs) with other systems, the use of techniques from other fields, such as machine learning and information processing, are becoming more common. Therefore, we faced the problem of missing network simulations that are not only focused on the packet exchange between network elements, but also in the data that is transmitted between them. In other words, we needed a tool that evaluated the WSNs on how they evolve and react to the environmental changes. To illustrate the benefits of having such perspective, we explain the kind of simulation problems that we solved in our last work. Moreover, we outline the next steps in the direction of creating an extension to support this approach.
Analysing Fuzzy Sets Through Combining Measures of Similarity and Distance
Venue: arXiv cs.AI 2014
Year: 2014

Reasoning with fuzzy sets can be achieved through measures such as similarity and distance. However, these measures can often give misleading results when considered independently, for example giving the same value for two different pairs of fuzzy sets. This is particularly a problem where many fuzzy sets are generated from real data, and while two different measures may be used to automatically compare such fuzzy sets, it is difficult to interpret two different results. This is especially true where a large number of fuzzy sets are being compared as part of a reasoning system. This paper introduces a method for combining the results of multiple measures into a single measure for the purpose of analysing and comparing fuzzy sets. The combined measure alleviates ambiguous results and aids in the automatic comparison of fuzzy sets. The properties of the combined measure are given, and demonstrations are presented with discussions on the advantages over using a single measure.