Information capacity

To date, the dominant approach to leadership research assumes that all aspects of the leadership role within a team are embodied by a single individual. In the real world, however, this is rarely the case. Rather, multiple individuals within the team may serve as leaders in both formal and informal capacities, and the shifting of leadership responsibilities is often rooted in which individual's expertise is most relevant to the given problem. In the present effort, we add to the rapidly growing body of work that focuses on the distribution of the leadership role among multiple individuals. We have reviewed relevant extant literature and proposed an integrated framework for understanding the collective leadership process. Also, in developing this framework we have taken an information and expertise-based approach such that we propose that collective leadership, or the distribution of the leadership role, is a function of selectively utilizing the information or specialized expertise that individuals within the network possess. In reviewing the framework, 55 propositions with regard to the collective leadership process are outlined and suggestions for future research are provided.

This paper is the first part of a trilogy, which comprises a detailed study of a special type of functional organization and demonstrates its relevance with respect to the origin and evolution of life. Self-replicative macromolecules, such as RNA or DNA in a suitable environment exhibit a behavior, which we may call Darwinian and which can be formally represented by the concept of the quasi-species. A quasi-species is defined as a given distribution of macromolecular species with closely interrelated sequences, dominated by one or several (degenerate) master copies. External constraints enforce the selection of the best adapted distribution, commonly referred to as the wild-type. Most important for Darwinian behavior are the criteria for internal stability of the quasi-species. If these criteria are violated, the information stored in the nucleotide sequence of the master copy will disintegrate irreversibly leading to an error catastrophy. As a consequence, selection and evolution of RNA or DNA molecules is limited with respect to the amount of information that can be stored in a single replicative unit. An analysis of experimental data regarding RNA and DNA replication at various levels of organization reveals, that a sufficient amount of information for the build up of a translation machinery can be gained only via integration of several different replicative units (or reproductive cycles) through functional linkages. A stable functional integration then will raise the system to a new level of organization and thereby enlarge its information capacity considerably. The hypercycle appears to be such a form of organization.

In this work, we propose a new type of activation function for a complex valued neural network (CVNN). This activation function is a special Möbius transformation classified as reflection. It is bounded outside of the unit disk and has partial continuous derivatives but not differentiable since it does not satisfy the Cauchy-Riemann equalities. However, the fixed points set of this function is a circle. Therefore, we employ this activation to a specific complex valued Hopfield neural network (CVHNN) and increase the number of fixed points. Using of this activation function leads us also to guarantee the existence of fixed points of the CVHNN. It is shown that the fixed points are all attractive which indicates that storage capacity of the CVHNN is enlarged.

Multiple antenna transmission methods are currently being developed all around the world for evolving 3G wireless standards. Space-Time Trellis Code (STTC) has been proven to use transmit diversity efficiently. It effectively exploits the effects of multipath fading to increase the information capacity of the multiple antenna transmission systems. STTC is a channel coding technique that maximises the 'distance' between different symbol matrices such that the probability of transmission errors are decreased when transmitting redundant symbol or in other words, to maximise the minimum determinant. Maximising the minimum determinant is equivalent to obtaining optimal generator matrix G. Instead of using state diagrams, optimal generator matrix G discussed in this paper is obtained using an improved algorithm which is based on Lisya tree structure. Optimal generator matrix G in this paper has a minimum determinant of 48 which is the highest coding gain obtained so far.

The aim of the present study was to investigate the imaging transfer characteristics and the luminescence efficiency (XLE) of powder scintillator for use in X-ray mammography detectors. emits in the red part of the visible spectrum, having very good spectral compatibility with optical sensors employed in digital imaging systems. Three powder scintillating screens, with coating thicknesses 33.1, 46.4 and 63.1 , were prepared in our laboratory. The imaging performance of these screens was assessed by experimental determination of the modulation transfer function (MTF), the noise transfer function (NTF) and the detective quantum efficiency (DQE) as well as a single index image quality parameter such as the information capacity (IC). A theoretical model, describing radiation and light transfer, was used to fit experimental MTF data. This has allowed the estimation of optical attenuation coefficients of the scintillator. In addition, a previously validated Monte Carlo code, based on the X-ray attenuation properties and on the Mie light scattering theory, was used to estimate the X-ray detection efficiency, the Swank factor and the zero frequency DQE of the scintillator. Results showed that exhibits high MTF and DQE values, which are comparable to those of a commercially employed screen. In addition shows high compatibility (effective gain) to CCDs and to recently introduced CMOS based detectors. Considering our image quality parameters and luminescence efficiency results, this material can potentially be considered for use in digital X-ray mammography detectors.

El artículo busca una comprensión del concepto «hábitat», a partir de la interpretación de los fenómenos de urbanización y de mutación en la ciudad y el territorio, tomando como punto de partida las experiencias del arquitecto holandés Rem Koolhaas con un grupo de estudiantes de la Universidad de Harvard, analizando las permutaciones en el desarrollo de las ciudades, junto a la apertura fronteriza, a revolución tecnológica, las nuevas tendencias en el estilo de vida, uso del tiempo, del espacio y en los hábitos de consumo. Se concluye que, para entender la complejidad del hábitat hay que vislumbrar su relación con los ecosistemas, en la fragmentación del espacio y en la segregación social, que obligan a un aumento de las mutaciones relacionadas con la capacidad de información, gestión, transporte y control. Palabras clave: Hábitat, ciudad, territorio, mutación.

The information capacity of wireless communication systems can be increased dramatically by employing multiple transmit and receive antennas [Foschini GJ, Gans MJ. On limits of wireless communications in a fading environment when using multiple antennas. An effective approach to increasing data rate over wireless channels is to employ coding techniques appropriate to multiple transmit antennas, that is space-time coding. Space-time codes introduce temporal and spatial correlation into signals transmitted from different antennas, in order to provide diversity at the receiver, and coding gain over an uncoded system. The spatial-temporal structure of these codes can be exploited to further increase the capacity of wireless systems with a relatively simple receiver structure. This paper provides an overview of space-time coding techniques and the associated signal processing framework.

Dimension schemas are abstract models of the data hierarchies that populate OLAP warehouses. Although there is abundant work on schema equivalence in a variety of data models, these works do not cover dimension schemas. In this paper we propose a notion of equivalence that allows to compare dimension schemas with respect to their information capacity. The proposed notion is intended to capture dimension schema equivalence in the context of OLAP schema restructuring. We offer characterizations of schema equivalence in terms of graph and schema isomorphisms, and present algorithms for testing it in well known classes of OLAP dimension schemas. Our results also permit to compare the expressiveness of different known classes of dimension schemas.

Conceptual schemata each representing some component of a system in the making, can be integrated in a variety of ways. Herein, we explore some fundamental notions of this. In particular, we examine some ways in which integration using correspondence assertions affects the interrelationship of two component schemata. Our analysis of the logic leads us to reject the commonly asserted requirement of constraining correspondence assertions to single predicates from a source schema. Much previous work has focussed on dominance with regard to preservation of information capacity as a primary integration criterion. However, even though it is desirable that the information capacity of a combined schema dominate one or both of its constituent schemata, we here discuss some aspects of why domination based on information capacity alone is insufficient for the integration to be semantically satisfactory, and we provide a framework for detecting mappings that prevent schema domination.

In this work, we propose a new type of activation function for a complex valued neural network (CVNN). This activation function is a special Möbius transformation classified as reflection. It is bounded outside of the unit disk and has partial continuous derivatives but not differentiable since it does not satisfy the Cauchy-Riemann equalities. However, the fixed points set of this function is a circle. Therefore, we employ this function to a specific complex valued Hopfield neural network (CVHNN) and increase the number of fixed points of the CVHNN. Using of this activation function leads us also to guarantee the existence of fixed points of the CVHNN. It is shown that the fixed points are all asymptotically stable states of the CVHNN which indicates that the information capacity is enlarged.

The aim of the present study was to investigate the imaging transfer characteristics and the luminescence efficiency (XLE) of Gd2O2S:Eu powder scintillator for use in X-ray mammography detectors. Gd2O2S:Eu emits in the red part of the visible spectrum, having very good spectral compatibility with optical sensors employed in digital imaging systems. Three Gd2O2S:Eu powder scintillating screens, with coating thicknesses 33.1, 46.4 and 63.1 mg/cm2 , were prepared in our laboratory. The imaging performance of these screens was assessed by experimental determination of the modulation transfer function (MTF), the noise transfer function (NTF) and the detective quantum efficiency (DQE) as well as a single index image quality parameter such as the information capacity (IC). A theoretical model, describing radiation and light transfer, was used to fit experimental MTF data. This has allowed the estimation of optical attenuation coefficients of the scintillator. In addition, a previously validated Monte Carlo code, based on the X-ray attenuation properties and on the Mie light scattering theory, was used to estimate the X-ray detection efficiency, the Swank factor and the zero frequency DQE of the Gd2O2S:Eu scintillator. Results showed that Gd2O2S:Eu exhibits high MTF and DQE values, which are comparable to those of a commercially employed Gd2O2S:Tb screen. In addition Gd2O2S:Eu shows high compatibility (effective gain) to CCDs and to recently introduced CMOS based detectors. Considering our image quality parameters and luminescence efficiency results, this material can potentially be considered for use in digital X-ray mammography detectors.

Integral imaging systems performance has been previously investigated with regard to different parameters such as lateral resolution, field of view, and depth of view. Those parameters are linked to one another, and, since the information capacity of an integral imaging system is finite, there are always trade-offs among them. We use the Shannon number and information capacity limit as figures of merit of integral imaging systems. The Shannon number and information capacity provide compact assessments of the system and are useful for analysis and design. The limitations on the Shannon number and the information capacity of an integral imaging system are determined by the recording and display media.

Currently, in the process of creating innovation, some new forms of R & D collaboration are emerging, to fulfil the demands of the knowledge-based systems that must integrate industrial, scientific and commercial elements. These new forms are normally based on an integration of several participants from different institutions becoming involved in an inter- sectoral collaboration. This has been the subject

The information capacity of wireless communication systems can be increased dramatically by employing multiple transmit and receive antennas [Foschini GJ, Gans MJ. On limits of wireless communications in a fading environment when using multiple antennas. An effective approach to increasing data rate over wireless channels is to employ coding techniques appropriate to multiple transmit antennas, that is space-time coding. Space-time codes introduce temporal and spatial correlation into signals transmitted from different antennas, in order to provide diversity at the receiver, and coding gain over an uncoded system. The spatial-temporal structure of these codes can be exploited to further increase the capacity of wireless systems with a relatively simple receiver structure. This paper provides an overview of space-time coding techniques and the associated signal processing framework.

To date, the dominant approach to leadership research assumes that all aspects of the leadership role within a team are embodied by a single individual. In the real world, however, this is rarely the case. Rather, multiple individuals within the team may serve as leaders in both formal and informal capacities, and the shifting of leadership responsibilities is often rooted in which individual's expertise is most relevant to the given problem. In the present effort, we add to the rapidly growing body of work that focuses on the distribution of the leadership role among multiple individuals. We have reviewed relevant extant literature and proposed an integrated framework for understanding the collective leadership process. Also, in developing this framework we have taken an information and expertise-based approach such that we propose that collective leadership, or the distribution of the leadership role, is a function of selectively utilizing the information or specialized expertise that individuals within the network possess. In reviewing the framework, 55 propositions with regard to the collective leadership process are outlined and suggestions for future research are provided.

Ultrafast superconductor digital microelectronic circuits operate at speeds up to 100 GHz, enabling true digital-RF architecture. This permits direct conversion between analog RF and digital baseband signals, replacing frequency and protocol-specific analog hardware with flexible, software-programmable digital processors. On the receive side, high sampling-speed (20 Gsamples/s) and linearity (>100 dB spur-free dynamic range) of superconductor analog-to-digital converters (ADCs), digital down-converters and ultrafast (20 GHz) digital filters have already been demonstrated by HYPRES. This will enable broadband digitization of the incoming RF waveform directly, leading to true digital channelization under full software control. In addition, the lower receiver noise temperature enhances information capacity, even in interference-limited systems. Similarly, on the transmit side, a high sampling-speed and quantum-linear digital-toanalog converter (DAC) preceded by digital up-converters and digital filters provide the scheme for direct synthesis of a spectrally pure RF transmit waveform. Furthermore, the power of digital processing at RF allows direct digital predistortion of the transmit waveform for linearization of the entire power amplifier chain. In this paper, we will discuss the benefits to future wireless systems, in terms of expanded range of high-data-rate coverage, lower handset battery power, higher spectral efficiency and lower cost for multi-carrier base-stations.

За участие в конкурс за "професор" на доц. д.ик.н. Желю Владимиров За участие в конкурса за "професор", обявен в ДВ, бр. 8 от 25.01.2011 г., шифър 05.02.20 "Социално управление" (Конкурентоспособност на малките и средните предприятия в България), е предоставен списък с 18 заглавия. В списъка са включени разработки, които не са представяни за участие в други конкурси.

Ultrafast superconductor digital microelectronic circuits operate at speeds up to 100 GHz, enabling true digital-RF architecture. This permits direct conversion between analog RF and digital baseband signals, replacing frequency and protocol-specific analog hardware with flexible, software-programmable digital processors. On the receive side, high sampling-speed (20 Gsamples/s) and linearity (>100 dB spur-free dynamic range) of superconductor analog-to-digital converters (ADCs), digital down-converters and ultrafast (20 GHz) digital filters have already been demonstrated by HYPRES. This will enable broadband digitization of the incoming RF waveform directly, leading to true digital channelization under full software control. In addition, the lower receiver noise temperature enhances information capacity, even in interference-limited systems. Similarly, on the transmit side, a high sampling-speed and quantum-linear digital-toanalog converter (DAC) preceded by digital up-converters and digital filters provide the scheme for direct synthesis of a spectrally pure RF transmit waveform. Furthermore, the power of digital processing at RF allows direct digital predistortion of the transmit waveform for linearization of the entire power amplifier chain. In this paper, we will discuss the benefits to future wireless systems, in terms of expanded range of high-data-rate coverage, lower handset battery power, higher spectral efficiency and lower cost for multi-carrier base-stations.

The information capacity of wireless communication systems can be increased dramatically by employing multiple transmit and receive antennas [Foschini GJ, Gans MJ. On limits of wireless communications in a fading environment when using multiple antennas. An effective approach to increasing data rate over wireless channels is to employ coding techniques appropriate to multiple transmit antennas, that is space-time coding. Space-time codes introduce temporal and spatial correlation into signals transmitted from different antennas, in order to provide diversity at the receiver, and coding gain over an uncoded system. The spatial-temporal structure of these codes can be exploited to further increase the capacity of wireless systems with a relatively simple receiver structure. This paper provides an overview of space-time coding techniques and the associated signal processing framework.

To date, the dominant approach to leadership research assumes that all aspects of the leadership role within a team are embodied by a single individual. In the real world, however, this is rarely the case. Rather, multiple individuals within the team may serve as leaders in both formal and informal capacities, and the shifting of leadership responsibilities is often rooted in which individual's expertise is most relevant to the given problem. In the present effort, we add to the rapidly growing body of work that focuses on the distribution of the leadership role among multiple individuals. We have reviewed relevant extant literature and proposed an integrated framework for understanding the collective leadership process. Also, in developing this framework we have taken an information and expertise-based approach such that we propose that collective leadership, or the distribution of the leadership role, is a function of selectively utilizing the information or specialized expertise that individuals within the network possess. In reviewing the framework, 55 propositions with regard to the collective leadership process are outlined and suggestions for future research are provided.

Recent renewed interest in the study of rhythmic behaviors and pattern-generating circuits has been inspired by the currently well-established role of oscillating neuronal networks in all aspects of the function of our nervous system: from sensory integration to central processing, and of course motor control. An integrative rather than reductionist approach in the study of pattern-generating circuits is in accordance with current developments. The lamprey spinal cord, a relatively simple and much studied preparation, is a useful model for such a study. It is an example of a chain of coupled oscillatory units that is characterized by its ability to demonstrate robust coordinated rhythmic output when isolated in vitro. The preparation allows maximum control over the chemical (neuromodulators and hormones) as well as neuronal environment (sensory and descending inputs) of the single oscillatory unit -the pattern-generating circuit. The current study made use of recently developed tools for nonlinear analysis of time-series, specifically neurophysiological signals. These tools allow us to reveal and characterize biological-functional complexity and information capacity of the neuronal output recorded from the lamprey model network. We focused on the importance of different types of inputs to an oscillatory network and their effect on the network's functional output. We show that the basic circuit, when isolated from short and long-range neuronal inputs, demonstrates its full potential of information capacity: maximal variation quantities and elevated functional complexity. Morphological and functional constraints result in the network exhibiting only a limited range of the above. This constitutes an important substrate for plasticity in neuronal network function.

A sparsely encoded Willshaw-like attractor neural network based on binary Hebbian synapses is investigated analytically and by computer simulations. A special inhibition mechanism which supports a constant number of active neurons at each time step is used. Informational capacity and size of attraction basins are evaluated for the single-step and the Gibson-Robinson approximations, as well as for experimental results.

Thirty-two children with Developmental Coordination Disorder (DCD) and learning disabilities (LD) and their age-matched controls attending normal primary schools were investigated using kinematic movement analysis of fine-motor performance. Three hypotheses about the nature of the motor deficits observed in children with LD were tested: general slowness hypothesis, limited information capacity hypothesis, and the motor control mode hypothesis. Measures of drawing movements were analyzed under different task conditions using a Fitts' paradigm. In a reciprocal aiming task, the children drew straight-line segments between two targets 2.5 cm apart. Three Target Sizes were used (0.22, 0.44, and 0.88 cm). Children used an electronic pen that left no trace on the writing tablet. To manipulate the degree of openloop movement control, the aiming task was performed under two different control regimes: discrete aiming and cyclic aiming. The kinematic analysis of the writing movements of the 32 children with DCD/LD that took part in the experimental study confirmed that besides learning disabilities they have a motor learning problem as well. Overall, the two groups did not Human Movement Science 22 www.elsevier.com/locate/humov differ in response time, nor did they respond differently according to Fitts' Law. Both groups displayed a conventional trade-off between Target Size and average Movement Time. However, while movement errors for children with DCD/LD were minimal on the discrete task, they made significantly more errors on the cyclic task. This, together with faster endpoint velocities, suggests a reduced ability to use a control strategy that emphasizes the terminal control of accuracy. Taken together, the results suggest that children with DCD/LD rely more on feedback during movement execution and have difficulty switching to a feedforward or openloop strategy.

In this work we address the statistical periodicity phenomenon on a coupled map lattice. The study was done based on the asymptotic binary patterns. The pattern multiplicity gives us the lattice information capacity, while the entropy rate allows us to calculate the lockingtime. Our results suggest that the lattice has low locking-time and high capacity information when the coupling is weak. This is the condition for the system to reproduce a kind of behavior observed in neural networks.

An information capacity-cost analysis is used to find a minimum cell size for information capacity increase in cellular wireless network, thus a theoretical limit to cell size reduction. The results show that as the cell size radius R reduces to 300 m and less, the proposed interference model show a 5.76-18.89 % decrease in the information capacity per unit cost (£, $, etc) at microwave carrier frequencies f c > 3.35 GHz. This result illustrates that there is a theoretical limit to cell size reduction in relation to information capacity performance and cost. An inductive approach is used to generate a formula for calculating the number of co-channel interfering cells N n in a cellular wireless site layout. Such a formula allows one to calculate the number of co-channel interfering cells in subsequent tiers of a cellular wireless site layout. The geometric derivation shows that the number of co-channel interfering cell N n in a subsequent tier is the product of the number of co-channel interfering cells in the first tier N I and the tier number n. Thus, the number of co-channel interfering cell in a subsequent tier N n = N I × n. This formula enables subsequent tier co-channel interference to be included in the information capacity analysis of future and emerging, and finding the minimum cell size for information capacity increase in a cellular wireless communication system.

The information content of medical images produced by X-ray beam±scintillator interaction was assessed by a method involving detective quantum eciency (DQE) and information capacity determination. The method was based on emitted light¯uence and modulation transfer function (MTF) measurements and it was employed to evaluate the performance of (Gd 0X5 La 0X5 ) 2 O 2 S:Tb scintillator, which was used in the form of laboratory prepared scintillator screens with coating weights ranging between 20 and 139 mgacm 2 . Screens were excited to luminescence using 80 and 120 kVp X-ray beams. The 83 mgacm 2 scintillator layer exhibited the highest DQE at zero spatial frequency. Thick scintillator layers displayed higher DQE values in the low frequency range while at high frequencies the DQE of thin scintillators were higher. Additionally, thin scintillator layers showed slow DQE variation with increasing frequency. The information capacity of scintillator layers decreased with increasing coating weight indicating that the information content of images produced by thin scintillating layers is higher and more evenly distributed with respect to spatial frequencies. Ó

Abstract. During the last decade many efforts for music information retrieval have been made utilizing Computational Intelligence methods. Here, we examine the information capacity of the Dodecaphonic Trace Vector for composer classification and identification. To this end, we utilize Probabilistic Neural Networks for the construction of a “similarity matrix” of different composers and analyze the Dodecaphonic Trace Vector's ability to identify a composer through trained Feedforward Neural Networks. The training procedure is based on ...

Thirty-two children with Developmental Coordination Disorder (DCD) and learning disabilities (LD) and their age-matched controls attending normal primary schools were investigated using kinematic movement analysis of fine-motor performance. Three hypotheses about the nature of the motor deficits observed in children with LD were tested: general slowness hypothesis, limited information capacity hypothesis, and the motor control mode hypothesis. Measures of drawing movements were analyzed under different task conditions using a Fitts' paradigm. In a reciprocal aiming task, the children drew straight-line segments between two targets 2.5 cm apart. Three Target Sizes were used (0.22, 0.44, and 0.88 cm). Children used an electronic pen that left no trace on the writing tablet. To manipulate the degree of openloop movement control, the aiming task was performed under two different control regimes: discrete aiming and cyclic aiming. The kinematic analysis of the writing movements of the 32 children with DCD/LD that took part in the experimental study confirmed that besides learning disabilities they have a motor learning problem as well. Overall, the two groups did not Human Movement Science 22 www.elsevier.com/locate/humov differ in response time, nor did they respond differently according to Fitts' Law. Both groups displayed a conventional trade-off between Target Size and average Movement Time. However, while movement errors for children with DCD/LD were minimal on the discrete task, they made significantly more errors on the cyclic task. This, together with faster endpoint velocities, suggests a reduced ability to use a control strategy that emphasizes the terminal control of accuracy. Taken together, the results suggest that children with DCD/LD rely more on feedback during movement execution and have difficulty switching to a feedforward or openloop strategy.

In an imaging system, it is known that the information capacity, rather than the resolution, is invariant. Thus super-resolution can be achieved by encoding/decoding additional information on to independent parameters of the imaging system. The concept of information capacity is extended to the full three-dimensional case.

The brain's capacity to analyse and interpret information is limited ultimately by the input it receives. This sets a premium on information capacity of sensory receptors, which can be maximized by optimizing sensitivity, speed and reliability of response. Nowhere is selection pressure for information capacity stronger than in the visual system, where speed and sensitivity can mean the difference between life and death. Phototransduction in flies represents the fastest G-protein-signalling cascade known. Analysis in Drosophila has revealed many of the underlying molecular strategies, leading to the discovery and characterization of signalling molecules of widespread importance.

Many problems in evolutionary theory are cast in dyadic terms, such as the polar oppositions of organism and environment. We argue that a triadic conceptual structure offers an alternative perspective under which the information generating role of evolution as a physical process can be analyzed, and propose a new diagrammatic approach. Peirce's natural philosophy was deeply influenced by his reception

Chair, Department Committee on Graduate Students I would like to express my deepest gratitude to my advisor, Vincent W.S. Chan, for his guidance, support, and patience. He taught me that asking the right question is just as important as the answer. His exceptional engineering intuition has always pushed me to look beyond the equations to understand things at a physical level. Vincent has always led by example, showing integrity and honesty-when it's easy to do so and when it's difficult to do so. I would like to thank Steve Prutzer for his encouragement and unequivocal support. It is because of his mentorship that I arrived at MIT prepared for the research ahead. I thank my thesis committee, Eric Swanson and Jeff Shapiro, for many useful comments and discussions. While both contributed to the thesis as a whole, Eric contributed much to the engineering while Jeff kept me firmly rooted in the physics. The friendship and administrative support offered by Donna Beaudry is much appreciated.

За участие в конкурс за "професор" на доц. д.ик.н. Желю Владимиров За участие в конкурса за "професор", обявен в ДВ, бр. 8 от 25.01.2011 г., шифър 05.02.20 "Социално управление" (Конкурентоспособност на малките и средните предприятия в България), е предоставен списък с 18 заглавия. В списъка са включени разработки, които не са представяни за участие в други конкурси.

Information capacity of a symbol sequence is a measure of the unexpectedness of a continuation of given string of symbols. Continuation of a string is determined through the maximum entropy of the reconstructed frequency dictionary; the capacity, in turn, is determined through the calculation of mutual entropy of a real frequency dictionary of a sequence with respect to the reconstructed one. The capacity does not depend on the length of strings in a dictionary. The capacity calculated for various genomes exhibits a multi-minima pattern reflecting an order observed within a sequence.

... Keita Tanaka 3 3 Research Center for Advanced Technologies, Tokyo Denki University Keiichi Saito 3 3 Research Center for Advanced Technologies, Tokyo Denki University Abstract Effect of information capacity and one week training of visuo-spatial memory task on brain ...

We study the statistics of optical data transmission in a noisy nonlinear fiber channel with a weak dispersion management and zero average dispersion. Applying analytical expressions for the output probability density functions both for a nonlinear channel and for a linear channel with additive and multiplicative noise we calculate in a closed form a lower bound estimate on the Shannon capacity for an arbitrary signal-to-noise ratio.

 The goal of the paper is discussion of possibilities, methods and results of application of optimal signal processing technique to optimisation and design of the cyclic A/D converters (CADC). There are analysed and explained, in detail, the sources and nature of new effects appearing in CADC with transition to computing sample codes using adaptive signal processing algorithms and long-word binary arithmetic. Efficiency of intelligent CADC (ICADC) built on this principle is conditioned by high efficiency of the algorithms used in their construction, which ensure work close to optimal and full utilisation of the resources of the analogue and the digital part of the converters. There are presented analytical expressions for theoretic upper boundaries of sub-optimal intelligent CADC resolution, speed of conversion and information capacity, which allow to assess and analyse performance of the converters, and to choose the variants best responding to given requirements. Principles of ICADC analysis and some questions of their practical implementation are discussed.

The paper evaluates a previous uni-axial creep testpiece design which has slitted extensometer ridges to relieve the constraint to axial deformation provided by conventional, or unslitted, ridges. The results of experiments are reported on slitted and unslitted ridged testpieees; and they are used together with theoretical studies to evaluate the effectiveness of the slitted ridged testpiece design for different specimen gauge lengths. Firstly, the test results are used to derive true constitutive equations (i.e. those equations for testpieces without ridges), these are then used to predict the response of the majority of the testpieces, using the creep Continuum Damage Mechanics (CDM) Finite Element solver DAMAGE XX. The creep rupture mechanisms, lifetimes and accuracy of the measured creep strains have been determined theoretically for testpieces with unslitted and slitted extensometer ridges and gauge lengths of 50, 30 and 10 ram. Close agreement has been obtained between the experimental and theoretical results for the creep failure mode and lifetimes. It has been shown how the accuracy of the creep behaviour measured using short gauge length testpieces (10 mm), of the type used in tension-compression testing, may be greatly improved by using slitted extensometer ridges.

View integration aims at replacing a set of existing views by a single new one in such a way that with respect to information capacity the new view dominates or is equivalent to the old ones. Therefore, in this article we first investigate a theory of schema equivalence and dominance for the higher-order Entity-Relationship model (HERM) based on the notion of computable queries. We then develop formal transformation rules for schema integration that are embedded in a pragmatic method telling how they should be applied for integration.

The information capacity of wireless communication systems can be increased dramatically by employing multiple transmit and receive antennas [Foschini GJ, Gans MJ. On limits of wireless communications in a fading environment when using multiple antennas. An effective approach to increasing data rate over wireless channels is to employ coding techniques appropriate to multiple transmit antennas, that is space-time coding. Space-time codes introduce temporal and spatial correlation into signals transmitted from different antennas, in order to provide diversity at the receiver, and coding gain over an uncoded system. The spatial-temporal structure of these codes can be exploited to further increase the capacity of wireless systems with a relatively simple receiver structure. This paper provides an overview of space-time coding techniques and the associated signal processing framework.

 In order to investigate the usefulness of unique synthetic DNA tracers in groundwater, a field experiment was conducted in Norway. DNA tracers and a sodium-chloride tracer were injected into an aquifer. The transport of DNA molecules was interpreted by comparing with the plume of chloride ions under forced-gradient steady-state flow conditions. Spatial concentration moments described the migration of conservative tracers. Mobility and migration of DNA in groundwater demonstrate that DNA tracers can be detected by using the polymerase chain reaction (PCR) and DNA sequence analysis. The results indicate that DNA tracers can be valuable tools as tracers in groundwater investigations. Afin d'analyser l'utilisation de traceurs ADN synthétiques uniques pour les eaux souterraines, une expérimentation a été conduite sur le terrain en Norvège. Des traceurs ADN et du chlorure de sodium ont été injectés dans un aquifère. Le transport des molécules d'ADN a été interprété par comparaison avec le panache d'ions chlorure soumis à des conditions d'écoulement en gradient imposé et en régime permanent. Les moments de la concentration spatiale décrivent la migration des traceurs conservatifs. La mobilité et la migration de l'ADN dans l'eau souterraine montrent que les traceurs ADN peuvent être détectés en utilisant une réaction polymérase en chaîne et l'analyse séquentielle de l'ADN. Les résultats indiquent que les traceurs ADN peuvent être des outils intéressants en tant que traceurs pour l'étude des eaux souterraines. Se realizó un experimento en Noruega para investigar la utilidad de un ADN sintético como trazador del agua subterránea en campo. Se inyectaron ADN y NaCl como trazadores bajo condiciones de flujo forzado estacionario, y se comparó el transporte de moléculas de ADN con el penacho de ion cloruro obtenido. La migración de los trazadores se describe mediante los momentos espaciales de la concentración. El ADN como trazador se detecta a partir de la reacción en cadena de polimerasa y la secuencia de análisis del ADN. Los resultados indican que el ADN puede ser un trazador útil para estudios hidrogeológicos.

It is shown that the capacity scaling of wireless networks is subject to a fundamental limitation which is independent of power attenuation and fading models. It is a degrees of freedom limitation which is due to the laws of physics. By distributing uniformly an order of n users wishing to establish pairwise independent communications at fixed wavelength inside a two-dimensional domain of size of the order of n, there are an order of n communication requests originating from the central half of the domain to its outer half. Physics dictates that the number of independent information channels across these two regions is only of the order of p n, so the per-user information capacity must follow an inverse square-root of n law. This result shows that information-theoretic limits of wireless communication problems can be rigorously obtained without relying on stochastic fading channel models, but studying their physical geometric structure.

This study examines the impact of fi nancial statements on the prices of companies traded in the Brazilian market and aims to verify how the returns of different -common and preferred capital -types of stock, react to the disclosure of annual fi nancial results. Hence, the methodology used by Ball and Brown (1968) was applied to two groups: the fi rst, made up by common stock, and the second by preferred capital stock. The samples were built on the basis of data for companies traded in the São Paulo Stock Exchange (BOVESPA), considering the period from 1990 to 2002. Evidence indicates that variations in the price of preferred capital stock are in accordance with disclosed results, which confi rms the hypothesis about the relevance of accounting information for investors. On the other hand, what common stock is concerned, the hypothesis was partially confi rmed, since only the portfolio with negative results followed the same direction as the disclosed results.

Recent renewed interest in the study of rhythmic behaviors and pattern-generating circuits has been inspired by the currently well-established role of oscillating neuronal networks in all aspects of the function of our nervous system: from sensory integration to central processing, and ...

Summary. Early physiological studies em- phasized changes in the discharge rate of basal ganglia in the pathophysiology of Parkinson's disease (PD), whereas recent studies stressed the role of the abnormal oscil- latory activity and neuronal synchronization of pallidal cells. However, human observa- tions cast doubt on the synchronization hypothesis since increased synchronization may be an epi-phenomenon of the tremor or

Recent progress in model-robust designs has focused on maximiz-1 ing estimation capacities. However, for a given design, two competing models may be both estimable and yet difficult or impossible to discriminate in the model selection procedure. In this paper, we propose several criteria for gauging the capability of a design for model discrimination. The criteria are then used to evaluate a class of 18-run orthogonal designs in terms of their model-discriminating capabilities.

This paper is concerned with capacity formulae for channels with memory and feedback, properties of the capacity achieving encoder, and dynamic programming for designing optimal encoders. The source is general and the techniques discussed include outputs of dynamic systems whose conditional probability distribution depends causally on the channel output and encoder law. First, encoder strategies are identified to maximize directed information, between the source and the channel output. Second, various definitions of information capacity are introduced via directed information, and converse coding theorems are derived. Encoder properties which lead to a tight upper bound on achievable rates are identified. Specifically, it is shown that channel inputs need to be independent of past channel outputs. Third, the form of the capacity achieving encoder is described. The encoder law is a functional of the a posteriori distribution of the source output given a sequence of observable channel outputs. Here a generalization of the Posterior Matching Scheme to channels with memory and feedback is shown to hold. Finally, dynamic programming is discussed, identifying analogies with optimal stochastic control under partial information.

Stochastic resonance (SR) is commonly understood to be the enhancement, by noise, of the response of a system to a weak input signal. The aim of this study was to demonstrate the occurrence of SR in spinal and cortical evoked field potentials (EFPs) elicited by periodic tactile stimuli in the anesthetized cat. The electrodes were positioned in spinal and cortical somatosensory regions in which the largest negative EFPs were detected. The periodic tactile stimuli consisted of local skin displacements on the central pad of the hindpaw. Two series of experiments were performed. First, periodic tactile stimuli and the noisy tactile stimuli were applied with the same indenter. Second, noisy tactile stimuli were applied with an additional indenter placed on the glabrous skin of the third hindpaw digit. This last protocol ensured that the signal and noise were mixed not in the skin but in the somatosensory regions of the CNS. All cats showed distinct SR behavior at the spinal and cortical ...