A WiMAX-based implementation of network MIMO for indoor wireless systems

It is well known that multiple-input multiple-output (MIMO) techniques can bring numerous benefits, such as higher spectral efficiency, to point-to-point wireless links. More recently, there has been interest in extending MIMO concepts tomultiuser wireless systems. Our focus in this paper is on network MIMO, a family of techniques whereby each end user in a wireless access network is served through several access points within its range of influence. By tightly coordinating the transmission and reception of signals at multiple access points, network MIMO can transcend the limits on spectral efficiency imposed by cochannel interference. Taking prior information-theoretic analyses of networkMIMO to the next level, we quantify the spectral efficiency gains obtainable under realistic propagation and operational conditions in a typical indoor deployment. Our study relies on detailed simulations and, for specificity, is conducted largely within the physical-layer framework of the IEEE 802.16e Mobile WiMAX system. Furthermore,to facilitate the coordination between access points, we assume that a high-capacity local area network, such as Gigabit Ethernet,connects all the access points. Our results confirm that network MIMO stands to provide a multiple-fold increase in spectralefficiency under these conditions.

Cross recurrence quantification for cover song identification

There is growing evidence that nonlinear time series analysis techniques can be used to successfully characterize, classify, or process signals derived from realworld dynamics even though these are not necessarily deterministic and stationary. In the present study we proceed in this direction by addressing an important problem our modern society is facing, the automatic classification of digital information. In particular, we address the automatic identification of cover songs, i.e. alternative renditions of a previously recorded musical piece. For this purpose we here propose a recurrence quantification analysis measure that allows tracking potentially curved and disrupted traces in cross recurrence plots. We apply this measure to cross recurrence plots constructed from the state space representation of musical descriptor time series extracted from the raw audio signal. We show that our method identifies cover songs with a higher accuracy as compared to previously published techniques. Beyond the particular application proposed here, we discuss how our approach can be useful for the characterization of a variety of signals from different scientific disciplines. We study coupled Rössler dynamics with stochastically modulated mean frequencies as one concrete example to illustrate this point.

Predictability of music descriptor time series and its application to cover song detection

Intuitively, music has both predictable and unpredictable components. In this work we assess this qualitative statement in a quantitative way using common time series models fitted to state-of-the-art music descriptors. These descriptors cover different musical facets and are extracted from a large collection of real audio recordings comprising a variety of musical genres. Our findings show that music descriptor time series exhibit a certain predictability not only for short time intervals, but also for mid-term and relatively long intervals. This fact is observed independently of the descriptor, musical facet and time series model we consider. Moreover, we show that our findings are not only of theoretical relevance but can also have practical impact. To this end we demonstrate that music predictability at relatively long time intervals can be exploited in a real-world application, namely the automatic identification of cover songs (i.e. different renditions or versions of the same musical piece). Importantly, this prediction strategy yields a parameter-free approach for cover song identification that is substantially faster, allows for reduced computational storage and still maintains highly competitive accuracies when compared to state-of-the-art systems.

Chroma binary similarity and local alignment applied to cover song identification

We present a new technique for audio signal comparison based on tonal subsequence alignment and its application to detect cover versions (i.e., different performances of the same underlying musical piece). Cover song identification is a task whose popularity has increased in the Music Information Retrieval (MIR) community along in the past, as it provides a direct and objective way to evaluate music similarity algorithms.This article first presents a series of experiments carried outwith two state-of-the-art methods for cover song identification.We have studied several components of these (such as chroma resolution and similarity, transposition, beat tracking or Dynamic Time Warping constraints), in order to discover which characteristics would be desirable for a competitive cover song identifier. After analyzing many cross-validated results, the importance of these characteristics is discussed, and the best-performing ones are finally applied to the newly proposed method. Multipleevaluations of this one confirm a large increase in identificationaccuracy when comparing it with alternative state-of-the-artapproaches.

The Multiscenario Multienvironment BioSecure Multimodal Database (BMDB)

A new multimodal biometric database designed and acquired within the framework of the European BioSecure Network of Excellence is presented. It is comprised of more than 600 individuals acquired simultaneously in three scenarios: 1) over the Internet, 2) in an office environment with desktop PC, and 3) in indoor/outdoor environments with mobile portable hardware. The three scenarios include a common part of audio/video data. Also, signature and fingerprint data have been acquired both with desktop PC and mobile portable hardware. Additionally, hand and iris data were acquired in the second scenario using desktop PC. Acquisition has been conducted by 11 European institutions. Additional features of the BioSecure Multimodal Database (BMDB) are: two acquisitionsessions, several sensors in certain modalities, balanced gender and age distributions, multimodal realistic scenarios with simple and quick tasks per modality, cross-European diversity, availability of demographic data, and compatibility with other multimodal databases. The novel acquisition conditions of the BMDB allow us to perform new challenging research and evaluation of eithermonomodal or multimodal biometric systems, as in the recent BioSecure Multimodal Evaluation campaign. A description of this campaign including baseline results of individual modalities from the new database is also given. The database is expected to beavailable for research purposes through the BioSecure Association during 2008.

A two-stage approach for tonic identification in indian art music

In this paper we propose a new approach for tonic identification in Indian art music and present a proposal for acomplete iterative system for the same. Our method splits the task of tonic pitch identification into two stages. In the first stage, which is applicable to both vocal and instrumental music, we perform a multi-pitch analysis of the audio signal to identify the tonic pitch-class. Multi-pitch analysisallows us to take advantage of the drone sound, which constantlyreinforces the tonic. In the second stage we estimate the octave in which the tonic of the singer lies and is thusneeded only for the vocal performances. We analyse the predominant melody sung by the lead performer in order to establish the tonic octave. Both stages are individually evaluated on a sizable music collection and are shown toobtain a good accuracy. We also discuss the types of errors made by the method.Further, we present a proposal for a system that aims to incrementally utilize all the available data, both audio and metadata in order to identify the tonic pitch. It produces a tonic estimate and a confidence value, and is iterative in nature. At each iteration, more data is fed into the systemuntil the confidence value for the identified tonic is above a defined threshold. Rather than obtain high overall accuracy for our complete database, ultimately our goal is to develop a system which obtains very high accuracy on a subset of the database with maximum confidence.

Applause identification and its relevance to archival of Carnatic music

A Carnatic music concert is made up of a sequence of pieces, where each piece corresponds to a particular genre and ra¯aga (melody). Unlike a western music concert, the artist may be applauded intra-performance inter-performance. Most Carnatic music that is archived today correspond to a single audio recordings of entire concerts.The purpose of this paper is to segment single audio recordings into a sequence of pieces using thecharacteristic features of applause and music. Spectral flux, spectral entropy change quite significantly from music to applause and vice-versa. The characteristics of these features for a subset of concerts was studied. A threshold based approach was used to segment the pieces into music fragments and applauses. Preliminary resultson recordings 19 concerts from matched microphones show that the EER is about 17% for a resolution of 0.25 seconds. Further, a parameter called CUSUM is estimatedfor the applause regions. The CUSUM values determine the strength of the applause. The CUSUM is used to characterise the highlights of a concert.

Analysis of the folksonomy of freesound

User generated content shared in online communities is often described using collaborative tagging systems where users assign labels to content resources. As a result, a folksonomy emerges that relates a number of tags with the resources they label and the users that have used them. In this paper we analyze the folksonomy of Freesound, an online audio clip sharing site which contains more than two million users and 150,000 user-contributed sound samplescovering a wide variety of sounds. By following methodologies taken from similar studies, we compute some metrics that characterize the folksonomy both at the globallevel and at the tag level. In this manner, we are able to betterunderstand the behavior of the folksonomy as a whole, and also obtain some indicators that can be used as metadata for describing tags themselves. We expect that such a methodology for characterizing folksonomies can be useful to support processes such as tag recommendation or automatic annotation of online resources.

Opportunities for a cultural specific approach in the computational description of music

The current research in Music Information Retrieval (MIR) is showing the potential that the Information Technologies can have in music related applications. Amajor research challenge in that direction is how to automaticallydescribe/annotate audio recordings and how to use the resulting descriptions to discover and appreciate music in new ways. But music is a complex phenomenonand the description of an audio recording has to deal with this complexity. For example, each musicculture has specificities and emphasizes different musicaland communication aspects, thus the musical recordings of each culture should be described differently. At the same time these cultural specificities give us the opportunity to pay attention to musical concepts andfacets that, despite being present in most world musics, are not easily noticed by listeners. In this paper we present some of the work done in the CompMusic project, including ideas and specific examples on how to take advantage of the cultural specificities of differentmusical repertoires. We will use examples from the art music traditions of India, Turkey and China.

Experiencias persuasivas: construcción de un protocolo para el análisis de la persuasión en los videojuegos

A pesar de que cada vez son más las investigaciones vinculadas al análisis de los videojuegos, pocas son las orientadas a determinar la articulación de su dimensión persuasiva. Partiendo principalmente de los trabajos de Ian Bogost y Gonzalo Frasca sobre la persuasión, se resiguen las carencias metodológicas de los modelos planteados y se proponen una serie de hipótesis orientadas a la búsqueda de una metodología que posibilite dar respuesta a la siguiente pregunta: ¿Cómo y dónde se articula la dimensión persuasiva de los videojuegos?En este sentido se trata de estudiar la dimensión persuasiva en los videojuegos de manera integral. La supuesta capacidad de las reglas de juego, propiedad intrínseca de los juegos y videojuegos, de determinar tanto la estructura narrativa como la parte audio/visual del texto (videojuego), así como su condición esencial de ser las portadoras de la carga persuasiva, permite apuntar como objetivo fundamental el diseño de un protocolo integral de la persuasión en los videojuegos

Milloria de cumplementació de l´estil Utstein. Incorporació d´un sistema de registre d´audio durant l´aturada cardíaca intrahospitalària

El registre precís de l´aturada cardíaca intrahospitalària seguint les recomanacions segons l´estil Utstein i mesurar els intèrvals de temps entre les diferents accions és difícil. L´estudi demostra que l'ús d'una gravadora amb temporitzador incorporat durant les maniobres de ressussitació cardiopulmonar en l´aturada cardíaca intrahospitalària permet el registre de més ítems per pacients i el càlcul dels intèrvals de temps entre les diferents accions durant les maniobres de reanimació cardiopulmonar de forma precisa i objectiva. Estudi observacional prospectiu entre gener de 2008 i desembre de 2009. S´inclouen pacients hospitalitzats i no hospitalitzats atesos per l´equip d´aturada cardíaca.

Signal analysis of Ney performances

Ney is an end-blown flute which is mainly used for Makam music. Although from the beginning of 20th century a score representation based on extending the Western musicis used, because of its rich articulation repertoire, actualNey music can not be totally represented by written score.Ney is still taught and transmitted orally in Turkey. Becauseof that the performance has a distinct and importantrole in Ney music. Therefore signal analysis of ney performancesis crucial for understanding the actual music.Another important aspect which is also a part of the performanceis the articulations that performers apply. In Makam music in Turkey none of the articulations are taught evennamed by teachers. Articulations in Ney are valuable for understanding the real performance. Since articulations are not taught and their places are not marked in the score, the choice and character of the articulation is unique for eachperformer which also makes each performance unique.Our method analyzes audio files of well known Turkish Ney players. In order to obtain our analysis data, we analyzed audio files of 8 different performers vary from 1920to 2000.

CashControl : Aplicación para el control de gastos

El objetivo de cashCONTROL es poder capturar de forma fácil un gasto para su posterior consulta. El programa no pretende ser un sistema de gestión contable. El principal propósito de la aplicación es hacer que la captura (o generación) de un gasto sea sencilla y se pueda realizar con un par de clics. La posibilidad de asociar información de audio a un gasto hace que sea muy fácil pasar gastos. Posteriormente, esos gastos pueden ser consultados para su inclusión en la contabilidad de cualquier organización o particular.

Control de 6 respiròmetres i anàlisi de les dades

L’aplicació de tècniques respiromètriques és de recent innovació dins l’estudi dels tractaments d’aigües residuals. Aquest conjunt de tècniques ens permeten analitzar dos processos importants dins una planta de tractament biològic: el creixement de la biomassa i el consum del substrat. Això fa que siguin una eina amb gran potencial en l’avaluació dels sistemes de tractament biològic d’aigües residuals. L’objectiu principal d’aquest treball es la realització d’una aplicació capaç de controlar el funcionament de 6 respiròmetres, gestionant el procés del mostreig de les respirometries i l’anàlisi de les dades obtingudes, per obtenir el substrat ràpidament biodegradable (Ss) per a mostres d’aigua residual, i la taxa màxima de creixement específic per a mostres de compost. L’aplicació s’ha desenvolupat sobre l’entorn Microsoft Access, on s’integren la base de dades amb les mostres i els resultats de les respirometries, i els formularis de control que ens permeten gestionar i controlar els processos de mostreig i anàlisi. L’aplicació es comunica amb els sensors i actuadors dels respiròmetres a través del control ActiveX, ADS-OCX, subministrat per TwinCAT, que ens permet capturar les lectures dels sensors i controlar el funcionament dels actuadors. Aquests elements estan connectats a mòduls descentralitzats d’entrades i sortides, comunicats mitjançant el bus Ethernet amb el PC-Industrial, on s’executa l’aplicació. Un cop finalitzada l’aplicació, aquesta controla correctament el mostreig de les respirometries, registrant les lectures de les sondes a la base de dades i controlant l’activació de les vàlvules del respiròmetre. Partint de les mostres obtingudes, o de respirometries externes, importades des de Microsoft Excel, s’ha comprovat el correcte funcionament en el càlcul del substrat ràpidament biodegradable (Ss) i la taxa màxima de creixement específic. Amb l’aplicació desenvolupada, s’ha comprovat el funcionament i les possibilitats que ens ofereix TwinCAT alhora de controlar mòduls d’entrades i sortides, així com la seva comunicació amb aplicacions com Microsoft Access. Això pot afavorir a la utilització d’aquest tipus de tecnologia, per aplicacions futures.

Control d'il·luminació i ventilació d'un pàrquing

El treball presentat ve motivat per la necessitat d’instal•lació d’un pàrquing públic i privat de nova construcció a nivell d’il•luminació i ventilació. Per poder satisfer les necessitats del nostre client d’estalvi energètic i confort en l’edifici es decideix d’implementar una instal•lació immòtica que és l’aplicació de tècniques de gestió i control automatitzat a un edifici terciari amb bus de comunicació KNX/EIB. Per a la il•luminació s’han utilitzat fluorescents amb balasts DALI, que permeten la seva regulació i control, per així poder adequar en tot moment l’encesa i intensitat de llum d’aquests. En quant a la ventilació s’han utilitzat variadors de freqüència per també poder optimitzar el funcionament dels ventiladors podent posar-los en marxa quan realment sigui necessari i a la potència que calgui. Per enllaçar tots els elements de la instal•lació, detectors i actuadors, sorgeig la necessitat d’implementar xarxes de comunicació com el KNX/EIB, DALI, Modbus i Ethernet. Per gestionar variables, comunicacions i controlar elements, s´hi han implementen dos autòmats programables a més d’un PC integrat per la visualització i el control del pàrquing. S’ha aconseguit de realitzar un pàrquing totalment automàtic on no és necessaria l’actuació dels operaris i amb les principals càrregues elèctriques totalment regulables en potència. S’ha comprovat que la instal•lació funciona per sota de la potència nominal de les càrregues amb l’estalvi energètic que això suposa.