OpenRaiser/Intern-Atlas huggingface dataset:
The exponential family in abstract information theory
Venue: arXiv cs.IT 2013
Year: 2013

We introduce generalized notions of a divergence function and a Fisher information matrix. We propose to generalize the notion of an exponential family of models by reformulating it in terms of the Fisher information matrix. Our methods are those of information geometry. The context is general enough to include applications from outside statistics.
Graph-based Generalization Bounds for Learning Binary Relations
Venue: arXiv cs.LG 2013
Year: 2013

We investigate the generalizability of learned binary relations: functions that map pairs of instances to a logical indicator. This problem has application in numerous areas of machine learning, such as ranking, entity resolution and link prediction. Our learning framework incorporates an example labeler that, given a sequence $X$ of $n$ instances and a desired training size $m$, subsamples $m$ pairs from $X \times X$ without replacement. The challenge in analyzing this learning scenario is that pairwise combinations of random variables are inherently dependent, which prevents us from using traditional learning-theoretic arguments. We present a unified, graph-based analysis, which allows us to analyze this dependence using well-known graph identities. We are then able to bound the generalization error of learned binary relations using Rademacher complexity and algorithmic stability. The rate of uniform convergence is partially determined by the labeler's subsampling process. We thus examine how various assumptions about subsampling affect generalization; under a natural random subsampling process, our bounds guarantee $\tilde{O}(1/\sqrt{n})$ uniform convergence.
Seeding Influential Nodes in Non-Submodular Models of Information Diffusion
Venue: arXiv cs.SI 2013
Year: 2013

We consider the model of information diffusion in social networks from \cite{Hui2010a} which incorporates trust (weighted links) between actors, and allows actors to actively participate in the spreading process, specifically through the ability to query friends for additional information. This model captures how social agents transmit and act upon information more realistically as compared to the simpler threshold and cascade models. However, it is more difficult to analyze, in particular with respect to seeding strategies. We present efficient, scalable algorithms for determining good seed sets -- initial nodes to inject with the information. Our general approach is to reduce our model to a class of simpler models for which provably good sets can be constructed. By tuning this class of simpler models, we obtain a good seed set for the original more complex model. We call this the \emph{projected greedy approach} because you `project' your model onto a class of simpler models where a greedy seed set selection is near-optimal. We demonstrate the effectiveness of our seeding strategy on synthetic graphs as well as a realistic San Diego evacuation network constructed during the 2007 fires.
A Review into eHealth Services and Therapies: Potential for Virtual Therapeutic Communities - Supporting People with Severe Personality Disorder
Venue: arXiv cs.CY 2013
Year: 2013

eHealth has expanded hugely over the last fifteen years and continues to evolve, providing greater benefits for patients, health care professionals and providers alike. The technologies that support these systems have become increasingly more sophisticated and have progressed significantly from standard databases, used for patient records, to highly advanced Virtual Reality (VR) systems for the treatment of complex mental health illnesses. The scope of this paper is to initially explore e-Health, particularly in relation to technologies supporting the treatment and management of wellbeing in mental health. It then provides a case study of how technology in e-Health can lend itself to an application that could support and maintain the wellbeing of people with a severe mental illness. The case study uses Borderline Personality Disorder as an example, but could be applicable in many other areas, including depression, anxiety, addiction and PTSD. This type of application demonstrates how e-Health can empower the individuals using it but also potentially reducing the impact upon health care providers and services.
The impact of teaching two courses (electronic curriculum design, multimedia) on the acquisition of electronic content design skills
Venue: arXiv cs.CY 2013
Year: 2013

The use of Multimedia applications in Learning provides useful concepts for Instructional Content Design. This study aimed to investigate the effect of design electronic curriculum and multimedia applications on acquiring e-content design skills, and improving their attitudes towards e-learning. To achieve the objective of the study, the researchers developed a test to measure the efficiencies of designing electronic content and the measure of attitudes towards e-learning, The results showed that study of both courses contributed positively to the acquisition of design skills of e-content, The results revealed that there are statistical significant differences between the scores of the students in the two applications (pre and post) on the total score of the attitude measure and three areas of it.
Memory Aware Load Balance Strategy on a Parallel Branch-and-Bound Application
Venue: arXiv cs.DC 2013
Year: 2013

The latest trends in high-performance computing systems show an increasing demand on the use of a large scale multicore systems in a efficient way, so that high compute-intensive applications can be executed reasonably well. However, the exploitation of the degree of parallelism available at each multicore component can be limited by the poor utilization of the memory hierarchy available. Actually, the multicore architecture introduces some distinct features that are already observed in shared memory and distributed environments. One example is that subsets of cores can share different subsets of memory. In order to achieve high performance it is imperative that a careful allocation scheme of an application is carried out on the available cores, based on a scheduling model that considers the main performance bottlenecks, as for example, memory contention. In this paper, the {\em Multicore Cluster Model} (MCM) is proposed, which captures the most relevant performance characteristics in multicores systems such as the influence of memory hierarchy and contention. Better performance was achieved when a load balance strategy for a Branch-and-Bound application applied to the Partitioning Sets Problem is based on MCM, showing its efficiency and applicability to modern systems.
Capacity Bounds for Wireless Ergodic Fading Broadcast Channels with Partial CSIT
Venue: arXiv cs.IT 2013
Year: 2013

The two-user wireless ergodic fading Broadcast Channel (BC) with partial Channel State Information at the Transmitter (CSIT) is considered. The CSIT is given by an arbitrary deterministic function of the channel state. This characteristic yields a full control over how much state information is available, from perfect to no information. In literature, capacity derivations for wireless ergodic fading channels, specifically for fading BCs, mostly rely on the analysis of channels comprising of parallel sub-channels. This technique is usually suitable for the cases where perfect state information is available at the transmitters. In this paper, new arguments are proposed to directly derive (without resorting to the analysis of parallel channels) capacity bounds for the two-user fading BC with both common and private messages based on the existing bounds for the discrete channel. Specifically, a novel approach is developed to adapt and evaluate the well-known UV-outer bound for the Gaussian fading channel using the entropy power inequality. Our approach indeed sheds light on the role of broadcast auxiliaries in the fading channel. It is shown that the derived outer bound is optimal for the channel with perfect CSIT as well as for some special cases with partial CSIT. Our outer bound is also directly applicable to the case without CSIT which has been recently considered in several papers. Next, the approach is developed to analyze for the fading BC with secrecy. In the case of perfect CSIT, a full characterization of the secrecy capacity region is derived for the channel with common and confidential messages. This result completes a gap in a previous work by Ekrem and Ulukus. For the channel without common message, the secrecy capacity region is also derived when the transmitter has access only to the degradedness ordering of the channel.
Budget Feasible Mechanisms for Experimental Design
Venue: arXiv cs.GT 2013
Year: 2013

In the classical experimental design setting, an experimenter E has access to a population of $n$ potential experiment subjects $i\in \{1,...,n\}$, each associated with a vector of features $x_i\in R^d$. Conducting an experiment with subject $i$ reveals an unknown value $y_i\in R$ to E. E typically assumes some hypothetical relationship between $x_i$'s and $y_i$'s, e.g., $y_i \approx βx_i$, and estimates $β$ from experiments, e.g., through linear regression. As a proxy for various practical constraints, E may select only a subset of subjects on which to conduct the experiment. We initiate the study of budgeted mechanisms for experimental design. In this setting, E has a budget $B$. Each subject $i$ declares an associated cost $c_i >0$ to be part of the experiment, and must be paid at least her cost. In particular, the Experimental Design Problem (EDP) is to find a set $S$ of subjects for the experiment that maximizes $V(S) = \log\det(I_d+\sum_{i\in S}x_i\T{x_i})$ under the constraint $\sum_{i\in S}c_i\leq B$; our objective function corresponds to the information gain in parameter $β$ that is learned through linear regression methods, and is related to the so-called $D$-optimality criterion. Further, the subjects are strategic and may lie about their costs. We present a deterministic, polynomial time, budget feasible mechanism scheme, that is approximately truthful and yields a constant factor approximation to EDP. In particular, for any small $δ> 0$ and $ε> 0$, we can construct a (12.98, $ε$)-approximate mechanism that is $δ$-truthful and runs in polynomial time in both $n$ and $\log\log\frac{B}{εδ}$. We also establish that no truthful, budget-feasible algorithms is possible within a factor 2 approximation, and show how to generalize our approach to a wide class of learning problems, beyond linear regression.
Probabilistic Non-Local Means
Venue: arXiv cs.CV 2013
Year: 2013

In this paper, we propose a so-called probabilistic non-local means (PNLM) method for image denoising. Our main contributions are: 1) we point out defects of the weight function used in the classic NLM; 2) we successfully derive all theoretical statistics of patch-wise differences for Gaussian noise; and 3) we employ this prior information and formulate the probabilistic weights truly reflecting the similarity between two noisy patches. The probabilistic nature of the new weight function also provides a theoretical basis to choose thresholds rejecting dissimilar patches for fast computations. Our simulation results indicate the PNLM outperforms the classic NLM and many NLM recent variants in terms of peak signal noise ratio (PSNR) and structural similarity (SSIM) index. Encouraging improvements are also found when we replace the NLM weights with the probabilistic weights in tested NLM variants.
Unified Modeling Language for Describing Business Value Chain Activities
Venue: arXiv cs.SE 2013
Year: 2013

With the market competition aggravating, it becomes necessary for market players to adopt a business model which can adopt dynamic business changes. Any enterprise has the possibility to win in the competition only when it forms the strategic alliance with the upstream and downstream enterprise. This paper articulates a way of using unified modelling language (UML) to develop business value chain activities for any enterprise to develop dynamic, adhoc and agile business model. The results show that the UML is useful in the development of information systems and is independent of any programming language.
An exact algorithm with the time complexity of $O^*(1.299^m)$ for the weighed mutually exclusive set cover problem
Venue: arXiv cs.DS 2013
Year: 2013

In this paper, we will introduce an exact algorithm with a time complexity of $O^*(1.299^m)$ for the {\sc weighted mutually exclusive set cover} problem, where $m$ is the number of subsets in the problem. This problem has important applications in recognizing mutation genes that cause different cancer diseases.
Parallel Suffix Array Construction by Accelerated Sampling
Venue: arXiv cs.DC 2013
Year: 2013

A deterministic BSP algorithm for constructing the suffix array of a given string is presented, based on a technique which we call accelerated sampling. It runs in optimal O(n/p) local computation and communication, and requires a near optimal O(log log p) synchronisation steps. The algorithm provides an improvement over the synchronisation costs of existing algorithms, and reinforces the importance of the sampling technique.
A universal, operational theory of unicast multi-user communication with fidelity criteria
Venue: arXiv cs.IT 2013
Year: 2013

This is a three part paper. Optimality of source-channel separation for communication with a fidelity criterion when the channel is compound as defined by Csiszar and Korner in their book and general as defined by Verdu and Han, is proved in Part I. It is assumed that random codes are permitted. The word "universal" in the title of this paper refers to the fact that the channel model is compound. The proof uses a layered black-box or a layered input-output view-point. In particular, only the end-to-end description of the channel as being capable of communicating a source to within a certain distortion level is used when proving separation. This implies that the channel model does not play any role for separation to hold as long as there is a source model. Further implications of the layered black-box view-point are discussed. Optimality of source-medium separation for multi-user communication with fidelity criteria over a general, compound medium in the unicast setting is proved in Part II, thus generalizing Part I to the unicast, multi-user setting. Part III gets to an understanding of the question, "Why is a channel which is capable of communicating a source to within a certain distortion level, also capable of communicating bits at any rate less than the infimum of the rates needed to code the source to within the distortion level": this lies at the heart of why optimality of separation for communication with a fidelity criterion holds. The perspective taken to get to this understanding is a randomized covering-packing perspective, and the proof is operational.
Performance Evaluation of Delay Tolerant Network in Heterogeneous Highly Dense Mobile Environment
Venue: arXiv cs.NI 2013
Year: 2013

Delay tolerant network (DTN) is opportunistic network where each node searches best opportunity to deliver the message called bundle to the destination. DTN implements a store and forward message switching system by simply introducing another new protocol layer called the Bundle Layer on top of the transport layer. The bundle layer is responsible for storing and forwarding entire message in message segments called bundles between source node and destination node. This paper evaluates the performance of delay tolerant network layer in heterogeneous highly dense mobile node environment. The heterogeneous network is created with the help of stationary wired node and Base Station node by introducing dynamic dense Mobile node network. Mobile nodes are assigned with continuous mobility. Three parameters are suggested $Δ$, $Θ$ and $λ$ to correlate the results obtained using rigorous simulation. Results show that after some threshold values, dense feature about mobile node does not pretend the delay cause for delay tolerant network packets. Also, increase in number of mobile node and number of File Transfer connection rarely change the overall performance of the delay tolerant network.
Optimization of thermal comfort in building through envelope design
Venue: arXiv cs.CE 2013
Year: 2013

Due to the current environmental situation, energy saving has become the leading drive in modern research. Although the residential houses in tropical climate do not use air conditioning to maintain thermal comfort in order to avoid use of electricity. As the thermal comfort is maintained by adequate envelope composition and natural ventilation, this paper shows that it is possible to determine the thickness of envelope layers for which the best thermal comfort is obtained. The building is modeled in EnergyPlus software and HookeJeves optimization methodology. The investigated house is a typical residential house one-storey high with five thermal zones located at Reunion Island, France. Three optimizations are performed such as the optimization of the thickness of the concrete block layer, of the wood layer, and that of the thermal insulation layer. The results show optimal thickness of thermal envelope layers that yield the maximum TC according to Fanger predicted mean vote.
Exact Safety Verification of Interval Hybrid Systems Based on Symbolic-Numeric Computation
Venue: arXiv cs.SC 2013
Year: 2013

In this paper, we address the problem of safety verification of interval hybrid systems in which the coefficients are intervals instead of explicit numbers. A hybrid symbolic-numeric method, based on SOS relaxation and interval arithmetic certification, is proposed to generate exact inequality invariants for safety verification of interval hybrid systems. As an application, an approach is provided to verify safety properties of non-polynomial hybrid systems. Experiments on the benchmark hybrid systems are given to illustrate the efficiency of our method.
Distributed Wear levelling of Flash Memories
Venue: arXiv cs.DC 2013
Year: 2013

For large scale distributed storage systems, flash memories are an excellent choice because flash memories consume less power, take lesser floor space for a target throughput and provide faster access to data. In a traditional distributed filesystem, even distribution is required to ensure load-balancing, balanced space utilisation and failure tolerance. In the presence of flash memories, in addition, we should also ensure that the number of writes to these different flash storage nodes are evenly distributed, to ensure even wear of flash storage nodes, so that unpredictable failures of storage nodes are avoided. This requires that we distribute updates and do garbage collection, across the flash storage nodes. We have motivated the distributed wearlevelling problem considering the replica placement algorithm for HDFS. Viewing the wearlevelling across flash storage nodes as a distributed co-ordination problem, we present an alternate design, to reduce the message communication cost across participating nodes. We demonstrate the effectiveness of our design through simulation
Upper Bounds on the Size of Grain-Correcting Codes
Venue: arXiv cs.DM 2013
Year: 2013

In this paper, we re-visit the combinatorial error model of Mazumdar et al. that models errors in high-density magnetic recording caused by lack of knowledge of grain boundaries in the recording medium. We present new upper bounds on the cardinality/rate of binary block codes that correct errors within this model.
Threshold-Coloring and Unit-Cube Contact Representation of Graphs
Venue: arXiv cs.DM 2013
Year: 2013

In this paper we study threshold coloring of graphs, where the vertex colors represented by integers are used to describe any spanning subgraph of the given graph as follows. Pairs of vertices with near colors imply the edge between them is present and pairs of vertices with far colors imply the edge is absent. Not all planar graphs are threshold-colorable, but several subclasses, such as trees, some planar grids, and planar graphs without short cycles can always be threshold-colored. Using these results we obtain unit-cube contact representation of several subclasses of planar graphs. Variants of the threshold coloring problem are related to well-known graph coloring and other graph-theoretic problems. Using these relations we show the NP-completeness for two of these variants, and describe a polynomial-time algorithm for another.
SecLaaS: Secure Logging-as-a-Service for Cloud Forensics
Venue: arXiv cs.CR 2013
Year: 2013

Cloud computing has emerged as a popular computing paradigm in recent years. However, today's cloud computing architectures often lack support for computer forensic investigations. Analyzing various logs (e.g., process logs, network logs) plays a vital role in computer forensics. Unfortunately, collecting logs from a cloud is very hard given the black-box nature of clouds and the multi-tenant cloud models, where many users share the same processing and network resources. Researchers have proposed using log API or cloud management console to mitigate the challenges of collecting logs from cloud infrastructure. However, there has been no concrete work, which shows how to provide cloud logs to investigator while preserving users' privacy and integrity of the logs. In this paper, we introduce Secure-Logging-as-a-Service (SecLaaS), which stores virtual machines' logs and provides access to forensic investigators ensuring the confidentiality of the cloud users. Additionally, SeclaaS preserves proofs of past log and thus protects the integrity of the logs from dishonest investigators or cloud providers. Finally, we evaluate the feasibility of the scheme by implementing SecLaaS for network access logs in OpenStack - a popular open source cloud platform.
An Iterative Noncoherent Relay Receiver for the Two-way Relay Channel
Venue: arXiv cs.IT 2013
Year: 2013

Physical-layer network coding improves the throughput of the two-way relay channel by allowing multiple source terminals to transmit simultaneously to the relay. However, it is generally not feasible to align the phases of the multiple received signals at the relay, which motivates the exploration of noncoherent solutions. In this paper, turbo-coded orthogonal multi-tone frequency-shift keying (FSK) is considered for the two-way relay channel. In contrast with analog network coding, the system considered is an instance of digital network coding; i.e., the relay decodes the network codeword and forwards a re-encoded version. Crucial to noncoherent digital network coding is the implementation of the relay receiver, which is the primary focus of the paper. The relay receiver derived in this paper supports any modulation order that is a power of two, and features the iterative feedback of a priori information from the turbo channel decoder to the demodulator; i.e., it uses bit interleaved coded modulation with iterative decoding (BICM-ID). The performance of the receiver is investigated in Rayeligh fading channels through error-rate simulations and a capacity analysis. Results show that the BICM-ID receiver improves energy efficiency by 0.5-0.9 dB compared to a non-iterative receiver implementation.
Mapping the Join Calculus to Heterogeneous Hardware
Venue: arXiv cs.DC 2013
Year: 2013

As modern architectures introduce additional heterogeneity and parallelism, we look for ways to deal with this that do not involve specialising software to every platform. In this paper, we take the Join Calculus, an elegant model for concurrent computation, and show how it can be mapped to an architecture by a Cartesian-product-style construction, thereby making use of the calculus' inherent non-determinism to encode placement choices. This unifies the concepts of placement and scheduling into a single task.