http://hdl.handle.net/2117/2136 Tue, 18 Jun 2013 21:52:14 GMT 2013-06-18T21:52:14Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/19544 Title: Quasi-digital conversion for resistive devices: application in GMR-based IC current sensors Authors: Reig, C.; Cubells, Miquel; De Marcellis, A.; Madrenas Boadas, Jordi; Cardoso, S.; Freitas, P.P. Abstract: Resistive devices, including sensors, are used in a huge range of applications within different scenarios. When a complete system is considered, a quasi-digital output is often recommendable. If the conversion is operated at device level, some problems such as noise disturbs, insertion losses and so on, can be reduced. In this work, we describe a resistance-tofrequency (R-f) converter with a suggested application in low current monitoring by means of GiantMagnetoResistance (GMR) sensors. Specific devices have been designed and microfabricated. The system has been tested by means of discrete components with a PCB. The complete microsystem monolithic integration in a standard CMOS technology has been also analyzed. Wed, 12 Jun 2013 17:03:54 GMT http://hdl.handle.net/2117/19544 2013-06-12T17:03:54Z Reig, C.; Cubells, Miquel; De Marcellis, A.; Madrenas Boadas, Jordi; Cardoso, S.; Freitas, P.P. no Sensors, CMOS integrated circuits, Electric current measurement, Electron devices, Oscillators (electronic), Polychlorinated biphenyls Resistive devices, including sensors, are used in a huge range of applications within different scenarios. When a complete system is considered, a quasi-digital output is often recommendable. If the conversion is operated at device level, some problems such as noise disturbs, insertion losses and so on, can be reduced. In this work, we describe a resistance-tofrequency (R-f) converter with a suggested application in low current monitoring by means of GiantMagnetoResistance (GMR) sensors. Specific devices have been designed and microfabricated. The system has been tested by means of discrete components with a PCB. The complete microsystem monolithic integration in a standard CMOS technology has been also analyzed. http://hdl.handle.net/2117/19502 Title: A bit more on the ability of adaptation of speech signals Authors: Ballesteros, Dora Maria; Moreno Aróstegui, Juan Manuel Abstract: Some traditional digital signal processing techniques encompass enhancement, filtering, coding, compression, detection and recognition. Recently, it has been presented a new hypothesis of signal processing known as the ability of adaptation of speech signals: an original speech signal may sound similar to a target speech signal if a relocation process of its wavelet coefficients is applied. This hypothesis is true under some conditions theoretically defined. In this paper we present the basic idea behind the hypothesis of adaptation and moreover, we test the hypothesis within four cases: speech signals with the same gender and language, speech signals with the same gender but different language, speech signals with the same language but different gender, and speech signals with different gender and language. It is found that the hypothesis is true if the requirements are satis® ed, even if the gender or the language of the original and target signals are not the same. Tue, 04 Jun 2013 13:00:09 GMT http://hdl.handle.net/2117/19502 2013-06-04T13:00:09Z Ballesteros, Dora Maria; Moreno Aróstegui, Juan Manuel no Ability of adaptation, speech signals, wavelet coefficients, similarity Some traditional digital signal processing techniques encompass enhancement, filtering, coding, compression, detection and recognition. Recently, it has been presented a new hypothesis of signal processing known as the ability of adaptation of speech signals: an original speech signal may sound similar to a target speech signal if a relocation process of its wavelet coefficients is applied. This hypothesis is true under some conditions theoretically defined. In this paper we present the basic idea behind the hypothesis of adaptation and moreover, we test the hypothesis within four cases: speech signals with the same gender and language, speech signals with the same gender but different language, speech signals with the same language but different gender, and speech signals with different gender and language. It is found that the hypothesis is true if the requirements are satis® ed, even if the gender or the language of the original and target signals are not the same. http://hdl.handle.net/2117/19449 Title: Real-time, speech-in-speech hiding scheme based on least significant bit substitution and adaptive key Authors: Ballesteros, Dora Maria; Moreno Aróstegui, Juan Manuel Abstract: Real-time, embedded speech-in-speech hiding has not been widely researched. Nevertheless, it could be useful, among other cases, in secure mobile telephony. In this paper, we propose a new scheme of data hiding which takes advantage of the masking property of the Human Auditory System (HAS) to hide a secret (speech) signal into a host (speech) signal. The embedding process is carried out into the wavelet coefficients of the speech signals. The main point of the proposed scheme is that the embedding process is suitable for real-time processing, and the secret’s coefficients are relocated by an adaptive key, instead of a pseudo-noise sequence of some approaches. The latency of the embedding module makes this approach useful for real-time speech communication because the total delay added by the proposed system is low compared to the highest delay allowed for a high quality speech transmission. Wed, 29 May 2013 17:57:37 GMT http://hdl.handle.net/2117/19449 2013-05-29T17:57:37Z Ballesteros, Dora Maria; Moreno Aróstegui, Juan Manuel no Speech communication, Audition, Speech, Speech transmission, Steganography Real-time, embedded speech-in-speech hiding has not been widely researched. Nevertheless, it could be useful, among other cases, in secure mobile telephony. In this paper, we propose a new scheme of data hiding which takes advantage of the masking property of the Human Auditory System (HAS) to hide a secret (speech) signal into a host (speech) signal. The embedding process is carried out into the wavelet coefficients of the speech signals. The main point of the proposed scheme is that the embedding process is suitable for real-time processing, and the secret’s coefficients are relocated by an adaptive key, instead of a pseudo-noise sequence of some approaches. The latency of the embedding module makes this approach useful for real-time speech communication because the total delay added by the proposed system is low compared to the highest delay allowed for a high quality speech transmission. http://hdl.handle.net/2117/19395 Title: A communication infrastructure for emulating large-scale neural networks models Authors: Barrera, A.G.; Moreno Aróstegui, Juan Manuel Abstract: This paper presents the SEPELYNS architecture that permits to in- terconnect multiple spiking neurons focused on hardware implementations. SEPELYNS can connect millions of neur ons with thousands of synapses per neuron in a layered fabric that provides some capabilities such as connectivity, expansion, flexibility, bio-plausibility and reusing of resources that allows si- mulation of very large networks. We presen t the three layers of this architecture (neuronal, network adapters and networks on chip layers) and explain its per- formance parameters such as throughput, latency and hardware resources. Some application examples of large neural networks on SEPELYNS are studied; these will show that use of on-chip parallel networks could permit the hardware simulation of populations of spiking neurons. Mon, 27 May 2013 08:33:20 GMT http://hdl.handle.net/2117/19395 2013-05-27T08:33:20Z Barrera, A.G.; Moreno Aróstegui, Juan Manuel no This paper presents the SEPELYNS architecture that permits to in- terconnect multiple spiking neurons focused on hardware implementations. SEPELYNS can connect millions of neur ons with thousands of synapses per neuron in a layered fabric that provides some capabilities such as connectivity, expansion, flexibility, bio-plausibility and reusing of resources that allows si- mulation of very large networks. We presen t the three layers of this architecture (neuronal, network adapters and networks on chip layers) and explain its per- formance parameters such as throughput, latency and hardware resources. Some application examples of large neural networks on SEPELYNS are studied; these will show that use of on-chip parallel networks could permit the hardware simulation of populations of spiking neurons. http://hdl.handle.net/2117/19174 Title: SIXE: An X-ray experiment for the MINISAT platform Authors: Bravo Guil, Eduardo; García-Berro Montilla, Enrique; Gutierrez Cabello, Jorge Luis; José Pont, Jordi; García Senz, Domingo; Cabestany Moncusí, Joan; Madrenas Boadas, Jordi Mon, 13 May 2013 09:46:38 GMT http://hdl.handle.net/2117/19174 2013-05-13T09:46:38Z Bravo Guil, Eduardo; García-Berro Montilla, Enrique; Gutierrez Cabello, Jorge Luis; José Pont, Jordi; García Senz, Domingo; Cabestany Moncusí, Joan; Madrenas Boadas, Jordi no http://hdl.handle.net/2117/17846 Title: Sense/Drive Architecture for CMOS-MEMS Accelerometers with Relaxation Oscillator and TDC Authors: Michalik, Piotr Jozef; Madrenas Boadas, Jordi; Fernández Martínez, Daniel Mon, 18 Feb 2013 15:02:12 GMT http://hdl.handle.net/2117/17846 2013-02-18T15:02:12Z Michalik, Piotr Jozef; Madrenas Boadas, Jordi; Fernández Martínez, Daniel no http://hdl.handle.net/2117/16976 Title: The Equilibrium-action cycle as a mechanism for design-evolution integration in autonomous behavior design Authors: Olivier, Paul; Moreno Aróstegui, Juan Manuel Tue, 20 Nov 2012 13:05:58 GMT http://hdl.handle.net/2117/16976 2012-11-20T13:05:58Z Olivier, Paul; Moreno Aróstegui, Juan Manuel no http://hdl.handle.net/2117/16737 Title: Highly transparent steganography model of speech signals using efficient wavelet masking Authors: Ballesteros, D.M.L.; Moreno Aróstegui, Juan Manuel Abstract: Steganography is the process of hiding information on a host signal. Transparency is referred to the ability to avoid suspicion about the existence of a secret message. The most popular mechanisms for hiding data in audio signals are the Least Significant Bit (LSB) substitution, Frequency Masking (FM), Spread Spectrum (SS), and Shift Spectrum Algorithm (SSA). In this paper, we adapt the Frequency Masking concept using an efficient sorting of the wavelet coefficients of the secret messages and use an indirect LSB substitution for hiding speech signals into speech signals. The experimental results show that the proposed model, the Efficient Wavelet Masking (EWM) scheme, has a hiding capacity significantly higher than the Spread and Shift Spectrum Algorithms and additionally a statistical transparency higher than all of the above mentioned mechanisms. Moreover, the transparency is not dependent of the host signal chosen because the wavelet sorting guarantees the adaptation of the secret message to the host signal. Wed, 17 Oct 2012 10:28:34 GMT http://hdl.handle.net/2117/16737 2012-10-17T10:28:34Z Ballesteros, D.M.L.; Moreno Aróstegui, Juan Manuel no Speech hiding, Steganalysis, Wavelet masking steganography Steganography is the process of hiding information on a host signal. Transparency is referred to the ability to avoid suspicion about the existence of a secret message. The most popular mechanisms for hiding data in audio signals are the Least Significant Bit (LSB) substitution, Frequency Masking (FM), Spread Spectrum (SS), and Shift Spectrum Algorithm (SSA). In this paper, we adapt the Frequency Masking concept using an efficient sorting of the wavelet coefficients of the secret messages and use an indirect LSB substitution for hiding speech signals into speech signals. The experimental results show that the proposed model, the Efficient Wavelet Masking (EWM) scheme, has a hiding capacity significantly higher than the Spread and Shift Spectrum Algorithms and additionally a statistical transparency higher than all of the above mentioned mechanisms. Moreover, the transparency is not dependent of the host signal chosen because the wavelet sorting guarantees the adaptation of the secret message to the host signal. http://hdl.handle.net/2117/16645 Title: LCMOS: Light-powered standard CMOS circuits Authors: Madrenas Boadas, Jordi; Fernández Martínez, Daniel; Wang, Chunyan Abstract: LCMOS, a harvest-use light-powered scheme for standard CMOS circuits based on photogenerated currents in the drain-substrate PN junction of both PMOS and NMOS transistors is introduced. PMOS and NMOS bulks are groundconnected so the generated currents induce symmetrical positive and negative voltage at the PMOS and NMOS sources, respectively. Applying this approach to a CMOS inverter ring oscillator in 150 nm technology, simulations show that nearly 1 Vpp signal range can be obtained. The operation of a simple 4- bit counter is also illustrated. The light-powering technique can be applied almost directly to digital standard cells in ultra-lowpower applications with modest processing speed requirements. Thu, 04 Oct 2012 12:00:10 GMT http://hdl.handle.net/2117/16645 2012-10-04T12:00:10Z Madrenas Boadas, Jordi; Fernández Martínez, Daniel; Wang, Chunyan no LCMOS, a harvest-use light-powered scheme for standard CMOS circuits based on photogenerated currents in the drain-substrate PN junction of both PMOS and NMOS transistors is introduced. PMOS and NMOS bulks are groundconnected so the generated currents induce symmetrical positive and negative voltage at the PMOS and NMOS sources, respectively. Applying this approach to a CMOS inverter ring oscillator in 150 nm technology, simulations show that nearly 1 Vpp signal range can be obtained. The operation of a simple 4- bit counter is also illustrated. The light-powering technique can be applied almost directly to digital standard cells in ultra-lowpower applications with modest processing speed requirements. http://hdl.handle.net/2117/16312 Title: POETIC-CUBES Authors: Paricio, Raquel; Moreno Aróstegui, Juan Manuel Fri, 20 Jul 2012 17:46:05 GMT http://hdl.handle.net/2117/16312 2012-07-20T17:46:05Z Paricio, Raquel; Moreno Aróstegui, Juan Manuel no http://hdl.handle.net/2117/16083 Title: Bio-inspired systems. Computational and ambient intelligence Authors: Sandoval, Francisco; Cabestany Moncusí, Joan; Prieto, Alberto Abstract: In the present issue of Neurocomputing, it is apleasure to present you a collection of 12 extended versions of selected papers from the 10 the dition of the International Work Conference on Artificial Neural Networks (IWANN2009). This is a conference held every two year in Spain, and focus in gon the foundations, theory, models and applications of systems, which are inspired by nature (e.g.neural networks, fuzzy logic and evolutionary systems). Mon, 18 Jun 2012 14:52:03 GMT http://hdl.handle.net/2117/16083 2012-06-18T14:52:03Z Sandoval, Francisco; Cabestany Moncusí, Joan; Prieto, Alberto no In the present issue of Neurocomputing, it is apleasure to present you a collection of 12 extended versions of selected papers from the 10 the dition of the International Work Conference on Artificial Neural Networks (IWANN2009). This is a conference held every two year in Spain, and focus in gon the foundations, theory, models and applications of systems, which are inspired by nature (e.g.neural networks, fuzzy logic and evolutionary systems). http://hdl.handle.net/2117/14496 Title: Continuous-time CMOS adaptive asynchronous sigma-delta modulator approximating low-fs low-inband-error on-chip wideband power amplifier Authors: Alarcón Cot, Eduardo José; Fernández, Diego; García Tormo, Albert; Madrenas Boadas, Jordi; Poveda López, Alberto Abstract: A mixed-signal continuous-time-processing standard CMOS implementation of an asynchronous sigma-delta modulator aimed to drive a switching amplifier operating as an on-chip wideband adaptive power supply is presented in this work. The paper first briefly discusses the fundamental limit tracking capabilities of a two-level switching signal to inband-error-free track a bandlimited signal with minimum average switching frequency. It is argued the adequacy of an adaptive asynchronous sigma-delta modulator (AAΣΔ) to approximate such fundamental characteristics. The second part of the paper presents mixed-signal design details of the various subcircuits implementing a CMOS low-power digitally-programmable AAΣΔ modulator, with 7 MHz average switching frequency operation and 1000 µm × 640 µm area occupancy. Thu, 12 Jan 2012 19:13:58 GMT http://hdl.handle.net/2117/14496 2012-01-12T19:13:58Z Alarcón Cot, Eduardo José; Fernández, Diego; García Tormo, Albert; Madrenas Boadas, Jordi; Poveda López, Alberto no A mixed-signal continuous-time-processing standard CMOS implementation of an asynchronous sigma-delta modulator aimed to drive a switching amplifier operating as an on-chip wideband adaptive power supply is presented in this work. The paper first briefly discusses the fundamental limit tracking capabilities of a two-level switching signal to inband-error-free track a bandlimited signal with minimum average switching frequency. It is argued the adequacy of an adaptive asynchronous sigma-delta modulator (AAΣΔ) to approximate such fundamental characteristics. The second part of the paper presents mixed-signal design details of the various subcircuits implementing a CMOS low-power digitally-programmable AAΣΔ modulator, with 7 MHz average switching frequency operation and 1000 µm × 640 µm area occupancy. http://hdl.handle.net/2117/14395 Title: A translinear, log-domain FPAA on standard CMOS technology Authors: Fernández, Daniel; Martínez Alvarado, Luis Arturo; Madrenas Boadas, Jordi Abstract: A field-programmable analog array (FPAA) using a standard-CMOS wide-dynamic-range translinear element (TE) is introduced. The FPAA configurable analog blocks (CABs) are based on a reconfigurable translinear cell (RTC), capable of implementing the basic circuit elements required by translinear and log-domain circuit design. The interfacing is provided by an I/O programmable cell, which allows for easier connectivity between the signal-processing core and the external circuitry. As a proof-of-concept, a 5 $times$ 5 RTC FPAA testchip was implemented in 0.35- $mu{hbox {m}}$ CMOS technology. A set of various circuit primitives, such as one- and four-quadrant multipliers, an Euclidean distance operator and a fourth-order log-domain filter, were mapped on the chip in order to demonstrate the versatility of the approach. FPAA bandwidth reaches 20 MHz with a power consumption of 30 $muhbox{W/TE}$ and precision errors below 3%. Mon, 02 Jan 2012 17:59:28 GMT http://hdl.handle.net/2117/14395 2012-01-02T17:59:28Z Fernández, Daniel; Martínez Alvarado, Luis Arturo; Madrenas Boadas, Jordi no A field-programmable analog array (FPAA) using a standard-CMOS wide-dynamic-range translinear element (TE) is introduced. The FPAA configurable analog blocks (CABs) are based on a reconfigurable translinear cell (RTC), capable of implementing the basic circuit elements required by translinear and log-domain circuit design. The interfacing is provided by an I/O programmable cell, which allows for easier connectivity between the signal-processing core and the external circuitry. As a proof-of-concept, a 5 $times$ 5 RTC FPAA testchip was implemented in 0.35- $mu{hbox {m}}$ CMOS technology. A set of various circuit primitives, such as one- and four-quadrant multipliers, an Euclidean distance operator and a fourth-order log-domain filter, were mapped on the chip in order to demonstrate the versatility of the approach. FPAA bandwidth reaches 20 MHz with a power consumption of 30 $muhbox{W/TE}$ and precision errors below 3%. http://hdl.handle.net/2117/14246 Title: Best-basis development towards the automatical detection of otolith irregularities in fishes Authors: Soria Pérez, José Antonio; Parisi Baradad, Vicenç Abstract: The application of feature extraction methodologies and the detection of patterns in sagitae otoliths, which are calcified structures in the inner ear of teleostean fishes, has lead to great knowledge of marine biology during the last decades in order to manage and control its sustainability. A main limitation of the use of statistical analysis and Fourier methods rely on their incapacity to locate irregularities and explain them from a more structural, or even physical, point of view. This matter has been addressed recently by means of the Best-Basis paradigm which combines robust description methods, such as the Wavelet Transform, and the potential of statistical analysis in order to fully automate the selection process of efficient features. This paper is an attempt to readdress this paradigm towards this goal and contrasts other standard tools used in the field of otolith-based fish recognition. The proposed strategy involves the estimation of class distributions, discriminant measures and the search in the feature space. Wed, 14 Dec 2011 12:59:50 GMT http://hdl.handle.net/2117/14246 2011-12-14T12:59:50Z Soria Pérez, José Antonio; Parisi Baradad, Vicenç no The application of feature extraction methodologies and the detection of patterns in sagitae otoliths, which are calcified structures in the inner ear of teleostean fishes, has lead to great knowledge of marine biology during the last decades in order to manage and control its sustainability. A main limitation of the use of statistical analysis and Fourier methods rely on their incapacity to locate irregularities and explain them from a more structural, or even physical, point of view. This matter has been addressed recently by means of the Best-Basis paradigm which combines robust description methods, such as the Wavelet Transform, and the potential of statistical analysis in order to fully automate the selection process of efficient features. This paper is an attempt to readdress this paradigm towards this goal and contrasts other standard tools used in the field of otolith-based fish recognition. The proposed strategy involves the estimation of class distributions, discriminant measures and the search in the feature space. http://hdl.handle.net/2117/13975 Title: Equilibrium-Driven Adaptive Behavior Design Authors: Olivier, Paul; Moreno Aróstegui, Juan Manuel Abstract: In autonomous robotics, scalability is a primary discriminator for evaluating a behavior design methodology. Such a proposed methodology must also allow efficient and effective conversion from desired to implemented behavior. From the concepts of equilibrium and homeostasis, it follows that behavior could be seen as driven rather than controlled. Homeostatic variables allow the development of need elements to completely implement drive and processing elements in a synthetic nervous system. Furthermore, an autonomous robot or system must act with a sense of meaning as opposed to being a human-command executor. Learning is fundamental in adding adaptability, and its efficient implementation will directly improve scalability. It is shown how using classical conditioning to learn obstacle avoidance can be implemented with need elements instead of an existing artificial neural network (ANN) solution. Fri, 18 Nov 2011 19:30:20 GMT http://hdl.handle.net/2117/13975 2011-11-18T19:30:20Z Olivier, Paul; Moreno Aróstegui, Juan Manuel no In autonomous robotics, scalability is a primary discriminator for evaluating a behavior design methodology. Such a proposed methodology must also allow efficient and effective conversion from desired to implemented behavior. From the concepts of equilibrium and homeostasis, it follows that behavior could be seen as driven rather than controlled. Homeostatic variables allow the development of need elements to completely implement drive and processing elements in a synthetic nervous system. Furthermore, an autonomous robot or system must act with a sense of meaning as opposed to being a human-command executor. Learning is fundamental in adding adaptability, and its efficient implementation will directly improve scalability. It is shown how using classical conditioning to learn obstacle avoidance can be implemented with need elements instead of an existing artificial neural network (ANN) solution.