OpenRaiser/Intern-Atlas huggingface dataset:
Proposta di nuovi strumenti per comprendere come funziona la cognizione (Novel tools to understand how cognition works)
Venue: arXiv cs.AI 2014
Year: 2014

I think that the main reason why we do not understand the general principles of how knowledge works (and probably also the reason why we have not yet designed and built efficient machines capable of artificial intelligence), is not the excessive complexity of cognitive phenomena, but the lack of the conceptual and methodological tools to properly address the problem. It is like trying to build up Physics without the concept of number, or to understand the origin of species without including the mechanism of natural selection. In this paper I propose some new conceptual and methodological tools, which seem to offer a real opportunity to understand the logic of cognitive processes. I propose a new method to properly treat the concepts of structure and schema, and to perform on them operations of structural analysis. These operations allow to move straightforwardly from concrete to more abstract representations. With these tools I will suggest a definition for the concept of rule, of regularity and of emergent phenomena. From the analysis of some important aspects of the rules, I suggest to distinguish them in operational and associative rules. I propose that associative rules assume a dominant role in cognition. I also propose a definition for the concept of problem. At the end I will briefly illustrate a possible general model for cognitive systems.
Fuzzy Inference System for VOLT/VAR control in distribution substations in isolated power systems
Venue: arXiv cs.SY 2014
Year: 2014

This paper presents a fuzzy inference system for voltage/reactive power control in distribution substations. The purpose is go forward to automation distribution and its implementation in isolated power systems where control capabilities are limited and it is common using the same applications as in continental power systems. This means that lot of functionalities do not apply and computational burden generates high response times. A fuzzy controller, with logic guidelines embedded based upon heuristic rules resulting from operators at dispatch control center past experience, has been designed. Working as an on-line tool, it has been tested under real conditions and it has managed the operation during a whole day in a distribution substation. Within the limits of control capabilities of the system, the controller maintained successfully an acceptable voltage profile, power factor values over 0,98 and it has ostensibly improved the performance given by an optimal power flow based automation system.
Approximating Large Frequency Moments with $O(n^{1-2/k})$ Bits
Venue: arXiv cs.DS 2014
Year: 2014

In this paper we consider the problem of approximating frequency moments in the streaming model. Given a stream $D = \{p_1,p_2,\dots,p_m\}$ of numbers from $\{1,\dots, n\}$, a frequency of $i$ is defined as $f_i = |\{j: p_j = i\}|$. The $k$-th \emph{frequency moment} of $D$ is defined as $F_k = \sum_{i=1}^n f_i^k$. In this paper we give an upper bound on the space required to find a $k$-th frequency moment of $O(n^{1-2/k})$ bits that matches, up to a constant factor, the lower bound of Woodruff and Zhang (STOC 12) for constant $ε$ and constant $k$. Our algorithm makes a single pass over the stream and works for any constant $k > 3$.
Adaptive Replication in Distributed Content Delivery Networks
Venue: arXiv cs.NI 2014
Year: 2014

We address the problem of content replication in large distributed content delivery networks, composed of a data center assisted by many small servers with limited capabilities and located at the edge of the network. The objective is to optimize the placement of contents on the servers to offload as much as possible the data center. We model the system constituted by the small servers as a loss network, each loss corresponding to a request to the data center. Based on large system / storage behavior, we obtain an asymptotic formula for the optimal replication of contents and propose adaptive schemes related to those encountered in cache networks but reacting here to loss events, and faster algorithms generating virtual events at higher rate while keeping the same target replication. We show through simulations that our adaptive schemes outperform significantly standard replication strategies both in terms of loss rates and adaptation speed.
Analyzing an Analytical Solution Model for Simultaneous Mobility
Venue: arXiv cs.NI 2014
Year: 2014

Current mobility models for simultaneous mobility have their convolution in designing simultaneous movement where mobile nodes (MNs) travel randomly from the two adjacent cells at the same time and also have their complexity in the measurement of the occurrences of simultaneous handover. Simultaneous mobility problem incurs when two of the MNs start handover approximately at the same time. As Simultaneous mobility is different for the other mobility pattern, generally occurs less number of times in real time; we analyze that a simplified simultaneous mobility model can be considered by taking only symmetric positions of MNs with random steps. In addition to that, we simulated the model using mSCTP and compare the simulation results in different scenarios with customized cell ranges. The analytical results shows that with the bigger the cell sizes, simultaneous handover with random steps occurrences become lees and for the sequential mobility (where initial positions of MNs is predetermined) with random steps, simultaneous handover is more frequent.
Key Performance Indicators for QOS Assessment in TETRA Networks
Venue: arXiv cs.NI 2014
Year: 2014

Key Performance Indicators (KPIs) are widely used by GSM and UMTS carriers with the aim of evaluating the network performance and the Quality of Service (QoS) delivered to users. TETRA networks are basically designed to provide telecommunication services to Public Safety & Security (PSS) organizations, thus the compliance of the QoS levels required by these clients is usually critical. Despite that, the use of KPIs to assess the network performance and the QoS achieved in TETRA systems is not very common. This paper not only states the need of monitoring and evaluating these parameters, but also introduces a set of KPIs which is considered necessary and sufficient in order to allow TETRA operators to be aware of whether provided services meet the QoS requirements established by end users.
Exploiting Frequency and Spatial Dimensions in Small Cell Wireless Networks
Venue: arXiv cs.IT 2014
Year: 2014

This paper examines the efficiency of spatial and frequency dimensions in serving multiple users in the downlink of a small cell wireless network with randomly deployed access points. For this purpose, the stochastic geometry framework is incorporated, taking into account the user distribution within each cell and the effect of sharing the available system resources to multiple users. An analysis of performance in terms of signal-to-interference-ratio and achieved user rate is provided that holds under the class of non-cooperative multiple access schemes. In order to obtain concrete results, two simple instances of multiple access schemes are considered. It is shown that performance depends critically on both the availability of frequency and/or spatial dimensions as well as the way they are employed. In particular, increasing the number of available frequency dimensions alone is beneficial for users experiencing large interference, whereas increasing spatial dimensions without employing frequency dimensions degrades performance. However, best performance is achieved when both dimensions are combined in serving the users.
A model project for reproducible papers: critical temperature for the Ising model on a square lattice
Venue: arXiv cs.CE 2014
Year: 2014

In this paper we present a simple, yet typical simulation in statistical physics, consisting of large scale Monte Carlo simulations followed by an involved statistical analysis of the results. The purpose is to provide an example publication to explore tools for writing reproducible papers. The simulation estimates the critical temperature where the Ising model on the square lattice becomes magnetic to be Tc /J = 2.26934(6) using a finite size scaling analysis of the crossing points of Binder cumulants. We provide a virtual machine which can be used to reproduce all figures and results.
New Approaches with Chord in Efficient P2P Grid Resource Discovery
Venue: arXiv cs.DC 2014
Year: 2014

Grid computing is a type of distributed computing which allows sharing of computer resources through Internet. It not only allows us to share files but also most of the software and hardware resources. An efficient resource discovery mechanism is the fundamental requirements for grid computing systems, as it supports resource management and scheduling of applications. Among various discovery mechanisms,Peer-to-Peer (P2P) technology witnessed rapid development and the key component for this success is efficient lookup applications of P2P. Chord is a P2P structural model widely used as a routing protocol to find resources in grid environment. Plenty of ideas are implemented by researchers to improve the lookup performance of chord protocol in Grid environment. In this paper, we discuss the recent researches made on Chord Structured P2P protocol and present our proposed methods in which we use the address of Recently Visited Node (RVN) and fuzzy technique to easily locate the grid resources by reducing message complexity and time complexity.
Gesture recognition based mouse events
Venue: arXiv cs.CV 2014
Year: 2014

This paper presents the maneuver of mouse pointer and performs various mouse operations such as left click, right click, double click, drag etc using gestures recognition technique. Recognizing gestures is a complex task which involves many aspects such as motion modeling, motion analysis, pattern recognition and machine learning. Keeping all the essential factors in mind a system has been created which recognizes the movement of fingers and various patterns formed by them. Color caps have been used for fingers to distinguish it from the background color such as skin color. Thus recognizing the gestures various mouse events have been performed. The application has been created on MATLAB environment with operating system as windows 7.
NextBestOnce: Achieving Polylog Routing despite Non-greedy Embeddings
Venue: arXiv cs.DS 2014
Year: 2014

Social Overlays suffer from high message delivery delays due to insufficient routing strategies. Limiting connections to device pairs that are owned by individuals with a mutual trust relationship in real life, they form topologies restricted to a subgraph of the social network of their users. While centralized, highly successful social networking services entail a complete privacy loss of their users, Social Overlays at higher performance represent an ideal private and censorship-resistant communication substrate for the same purpose. Routing in such restricted topologies is facilitated by embedding the social graph into a metric space. Decentralized routing algorithms have up to date mainly been analyzed under the assumption of a perfect lattice structure. However, currently deployed embedding algorithms for privacy-preserving Social Overlays cannot achieve a sufficiently accurate embedding and hence conventional routing algorithms fail. Developing Social Overlays with acceptable performance hence requires better models and enhanced algorithms, which guarantee convergence in the presence of local optima with regard to the distance to the target. We suggest a model for Social Overlays that includes inaccurate embeddings and arbitrary degree distributions. We further propose NextBestOnce, a routing algorithm that can achieve polylog routing length despite local optima. We provide analytical bounds on the performance of NextBestOnce assuming a scale-free degree distribution, and furthermore show that its performance can be improved by more than a constant factor when including Neighbor-of-Neighbor information in the routing decisions.
A biologically inspired model for transshipment problem
Venue: arXiv cs.SY 2014
Year: 2014

Transshipment problem is one of the basic operational research problems. In this paper, our first work is to develop a biologically inspired mathematical model for a dynamical system, which is first used to solve minimum cost flow problem. It has lower computational complexity than Physarum Solver. Second, we apply the proposed model to solve the traditional transshipment problem. Compared with the conditional methods, experiment results show the provided model is simple, effective as well as handling problem in a continuous manner.
Analog Network Coding for Multi-User Spread-Spectrum Communication Systems
Venue: arXiv cs.IT 2014
Year: 2014

This work presents another look at an analog network coding scheme for multi-user spread-spectrum communication systems. Our proposed system combines coding and cooperation between a relay and users to boost the throughput and to exploit interference. To this end, each pair of users, $\mathcal{A}$ and $\mathcal{B}$, that communicate with each other via a relay $\mathcal{R}$ shares the same spreading code. The relay has two roles, it synchronizes network transmissions and it broadcasts the combined signals received from users. From user $\mathcal{B}$'s point of view, the signal is decoded, and then, the data transmitted by user $\mathcal{A}$ is recovered by subtracting user $\mathcal{B}$'s own data. We derive the analytical performance of this system for an additive white Gaussian noise channel with the presence of multi-user interference, and we confirm its accuracy by simulation.
Assessing Wikipedia-Based Cross-Language Retrieval Models
Venue: arXiv cs.IR 2014
Year: 2014

This work compares concept models for cross-language retrieval: First, we adapt probabilistic Latent Semantic Analysis (pLSA) for multilingual documents. Experiments with different weighting schemes show that a weighting method favoring documents of similar length in both language sides gives best results. Considering that both monolingual and multilingual Latent Dirichlet Allocation (LDA) behave alike when applied for such documents, we use a training corpus built on Wikipedia where all documents are length-normalized and obtain improvements over previously reported scores for LDA. Another focus of our work is on model combination. For this end we include Explicit Semantic Analysis (ESA) in the experiments. We observe that ESA is not competitive with LDA in a query based retrieval task on CLEF 2000 data. The combination of machine translation with concept models increased performance by 21.1% map in comparison to machine translation alone. Machine translation relies on parallel corpora, which may not be available for many language pairs. We further explore how much cross-lingual information can be carried over by a specific information source in Wikipedia, namely linked text. The best results are obtained using a language modeling approach, entirely without information from parallel corpora. The need for smoothing raises interesting questions on soundness and efficiency. Link models capture only a certain kind of information and suggest weighting schemes to emphasize particular words. For a combined model, another interesting question is therefore how to integrate different weighting schemes. Using a very simple combination scheme, we obtain results that compare favorably to previously reported results on the CLEF 2000 dataset.
Transformation-based Feature Computation for Algorithm Portfolios
Venue: arXiv cs.AI 2014
Year: 2014

Instance-specific algorithm configuration and algorithm portfolios have been shown to offer significant improvements over single algorithm approaches in a variety of application domains. In the SAT and CSP domains algorithm portfolios have consistently dominated the main competitions in these fields for the past five years. For a portfolio approach to be effective there are two crucial conditions that must be met. First, there needs to be a collection of complementary solvers with which to make a portfolio. Second, there must be a collection of problem features that can accurately identify structural differences between instances. This paper focuses on the latter issue: feature representation, because, unlike SAT, not every problem has well-studied features. We employ the well-known SATzilla feature set, but compute alternative sets on different SAT encodings of CSPs. We show that regardless of what encoding is used to convert the instances, adequate structural information is maintained to differentiate between problem instances, and that this can be exploited to make an effective portfolio-based CSP solver.
A Study of Image Analysis with Tangent Distance
Venue: arXiv cs.CV 2014
Year: 2014

The computation of the geometric transformation between a reference and a target image, known as registration or alignment, corresponds to the projection of the target image onto the transformation manifold of the reference image (the set of images generated by its geometric transformations). It, however, often takes a nontrivial form such that the exact computation of projections on the manifold is difficult. The tangent distance method is an effective algorithm to solve this problem by exploiting a linear approximation of the manifold. As theoretical studies about the tangent distance algorithm have been largely overlooked, we present in this work a detailed performance analysis of this useful algorithm, which can eventually help its implementation. We consider a popular image registration setting using a multiscale pyramid of lowpass filtered versions of the (possibly noisy) reference and target images, which is particularly useful for recovering large transformations. We first show that the alignment error has a nonmonotonic variation with the filter size, due to the opposing effects of filtering on both manifold nonlinearity and image noise. We then study the convergence of the multiscale tangent distance method to the optimal solution. We finally examine the performance of the tangent distance method in image classification applications. Our theoretical findings are confirmed by experiments on image transformation models involving translations, rotations and scalings. Our study is the first detailed study of the tangent distance algorithm that leads to a better understanding of its efficacy and to the proper selection of its design parameters.
Zero-Delay Joint Source-Channel Coding for a Multivariate Gaussian on a Gaussian MAC
Venue: arXiv cs.IT 2014
Year: 2014

In this paper, communication of a Multivariate Gaussian over a Gaussian Multiple Access Channel is studied. Distributed zero-delay joint source-channel coding (JSCC) solutions to the problem are given. Both nonlinear and linear approaches are discussed. The performance upper bound (signal-to-distortion ratio) for arbitrary code length is also derived and Zero-delay cooperative JSCC is briefly addressed in order to provide an approximate bound on the performance of zero-delay schemes. The main contribution is a nonlinear hybrid discrete-analog JSSC scheme based on distributed quantization and a linear continuous mapping named Distributed Quantizer Linear Coder (DQLC). The DQLC has promising performance which improves with increasing correlation, and is robust against variations in noise level. The DQLC exhibits a constant gap to the performance upper bound as the signal-to-noise ratio (SNR) becomes large for any number of sources and values of correlation. Therefore it outperforms a linear solution (uncoded transmission) in any case when the SNR gets sufficiently large.
Improving Quality of Clustering using Cellular Automata for Information retrieval
Venue: arXiv cs.IR 2014
Year: 2014

Clustering has been widely applied to Information Retrieval (IR) on the grounds of its potential improved effectiveness over inverted file search. Clustering is a mostly unsupervised procedure and the majority of the clustering algorithms depend on certain assumptions in order to define the subgroups present in a data set .A clustering quality measure is a function that, given a data set and its partition into clusters, returns a non-negative real number representing the quality of that clustering. Moreover, they may behave in a different way depending on the features of the data set and their input parameters values. Therefore, in most applications the resulting clustering scheme requires some sort of evaluation as regards its validity. The quality of clustering can be enhanced by using a Cellular Automata Classifier for information retrieval. In this study we take the view that if cellular automata with clustering is applied to search results (query-specific clustering), then it has the potential to increase the retrieval effectiveness compared both to that of static clustering and of conventional inverted file search. We conducted a number of experiments using ten document collections and eight hierarchic clustering methods. Our results show that the effectiveness of query-specific clustering with cellular automata is indeed higher and suggest that there is scope for its application to IR.
PSMACA: An Automated Protein Structure Prediction Using MACA (Multiple Attractor Cellular Automata)
Venue: arXiv cs.CE 2014
Year: 2014

Protein Structure Predication from sequences of amino acid has gained a remarkable attention in recent years. Even though there are some prediction techniques addressing this problem, the approximate accuracy in predicting the protein structure is closely 75%. An automated procedure was evolved with MACA (Multiple Attractor Cellular Automata) for predicting the structure of the protein. Most of the existing approaches are sequential which will classify the input into four major classes and these are designed for similar sequences. PSMACA is designed to identify ten classes from the sequences that share twilight zone similarity and identity with the training sequences. This method also predicts three states (helix, strand, and coil) for the structure. Our comprehensive design considers 10 feature selection methods and 4 classifiers to develop MACA (Multiple Attractor Cellular Automata) based classifiers that are build for each of the ten classes. We have tested the proposed classifier with twilight-zone and 1-high-similarity benchmark datasets with over three dozens of modern competing predictors shows that PSMACA provides the best overall accuracy that ranges between 77% and 88.7% depending on the dataset.
Participant: A New Concept for Optimally Assisting the Elder People
Venue: arXiv cs.CY 2014
Year: 2014

Elder people are becoming a predominant aspect of our societies. As such, solutions both efficacious and cost-effective need to be sought. The approach pursued so far to solve this problem used to increase the number of people working in the health sector, e.g. doctors, nurses, etc. This increases the costs, which is becoming a big burden for countries. In this paper we propose a new concept in the health management of elder people, which we name as "participant". We propose the "participant" concept to encourage elder people to participate in those group activities that they are able to. Their roles in these activities are not passively requesting help, but actively participating to some healthcare processes. Characteristics of the participant approach are that medical resources are efficiently spared with this model, and the social network of the elder people is kept. A "virtual community" for mutual assistance is set up in this paper, and the simulations demonstrate that the "participant" model could fully utilize the community resources. Furthermore, the psychological health of the elder people will be improved.