Entropy and Hausdorff Dimension in Random Growing Trees

We investigate the limiting behavior of random tree growth in preferential attachment models. The tree stems from a root, and we add vertices to the system one-by-one at random, according to a rule which depends on the degree distribution of the already existing tree. The so-called weight function, in terms of which the rule of attachment is formulated, is such that each vertex in the tree can have at most K children. We define the concept of a certain random measure mu on the leaves of the limiting tree, which captures a global property of the tree growth in a natural way. We prove that the Hausdorff and the packing dimension of this limiting measure is equal and constant with probability one. Moreover, the local dimension of mu equals the Hausdorff dimension at mu-almost every point. We give an explicit formula for the dimension, given the rule of attachment

A remote sensing approach to assess algal beta-carotene content in solar salt evaporation ponds

The present research attempts to calibrate satellite images against field data on D. salina ß-carotene concentration expressed per 1 L of brine. We found the empirical relation between ß-carotene quantity and the index based on two infrared reflectance bands (NIR and SWIR)

Improved Numerical Simulation for a Novel Adaptive Control Using Fractional Order Derivatives

A novel control technique is investigated in the adaptive control of a typical paradigm, an approximately and partially modeled cart plus double pendulum system. In contrast to the traditional approaches that try to build up ”complete” and ”permanent” system models it develops ”temporal” and ”partial” ones that are valid only in the actual dynamic environment of the system, that is only within some ”spatio-temporal vicinity” of the actual observations. This technique was investigated for various physical systems via ”preliminary” simulations integrating by the simplest 1st order finite element approach for the time domain. In 2004 INRIA issued its SCILAB 3.0 and its improved numerical simulation tool ”Scicos” making it possible to generate ”professional”, ”convenient”, and accurate simulations. The basic principles of the adaptive control, the typical tools available in Scicos, and others developed by the authors, as well as the improved simulation results and conclusions are presented in the contribution

Simple Kinematic Design for Evading the Forced Oscillation of a Car-Wheel Suspension System

An adaptive control damping the forced vibration of a car while passing along a bumpy road is investigated. It is based on a simple kinematic description of the desired behavior of the damped system. A modified PID controller containing an approximation of Caputo’s fractional derivative suppresses the high-frequency components related to the bumps and dips, while the low frequency part of passing hills/valleys are strictly traced. Neither a complete dynamic model of the car nor ’a priori’ information on the surface of the road is needed. The adaptive control realizes this kinematic design in spite of the existence of dynamically coupled, excitable internal degrees of freedom. The method is investigated via Scicos-based simulation in the case of a paradigm. It was found that both adaptivity and fractional order derivatives are essential parts of the control that can keep the vibration of the load at bay without directly controlling its motion

On the robustness of the slotine-Li and the FPT/SVD-based adaptive controllers

A comparative study concerning the robustness of a novel, Fixed Point Transformations/Singular Value Decomposition (FPT/SVD)-based adaptive controller and the Slotine-Li (S&L) approach is given by numerical simulations using a three degree of freedom paradigm of typical Classical Mechanical systems, the cart + double pendulum. The effects of the imprecision of the available dynamical model, presence of dynamic friction at the axles of the drives, and the existence of external disturbance forces unknown and not modeled by the controller are considered. While the Slotine-Li approach tries to identify the parameters of the formally precise, available analytical model of the controlled system with the implicit assumption that the generalized forces are precisely known, the novel one makes do with a very rough, affine form and a formally more precise approximate model of that system, and uses temporal observations of its desired vs. realized responses. Furthermore, it does not assume the lack of unknown perturbations caused either by internal friction and/or external disturbances. Its another advantage is that it needs the execution of the SVD as a relatively time-consuming operation on a grid of a rough system-model only one time, before the commencement of the control cycle within which it works only with simple computations. The simulation examples exemplify the superiority of the FPT/SVD-based control that otherwise has the deficiency that it can get out of the region of its convergence. Therefore its design and use needs preliminary simulation investigations. However, the simulations also exemplify that its convergence can be guaranteed for various practical purposes

An international network to monitor the structure, composition and dynamics of Amazonian forests (RAINFOR)

The Amazon basin is likely to be increasingly affected by environmental changes: higher temperatures, changes in precipitation, CO2 fertilization and habitat fragmentation. To examine the important ecological and biogeochemical consequences of these changes, we are developing an international network, RAINFOR, which aims to monitor forest biomass and dynamics across Amazonia in a co-ordinated fashion in order to understand their relationship to soil and climate. The network will focus on sample plots established by independent researchers, some providing data extending back several decades. We will also conduct rapid transect studies of poorly monitored regions. Field expeditions analysed local soil and plant properties in the first phase (2001–2002). Initial results suggest that the network has the potential to reveal much information on the continental-scale relations between forest and environment. The network will also serve as a forum for discussion between researchers, with the aim of standardising sampling techniques and methodologies that will enable Amazonian forests to be monitored in a coherent manner in the coming decades

Diameters in preferential attachment models

In this paper, we investigate the diameter in preferential attachment (PA-) models, thus quantifying the statement that these models are small worlds. The models studied here are such that edges are attached to older vertices proportional to the degree plus a constant, i.e., we consider affine PA-models. There is a substantial amount of literature proving that, quite generally, PA-graphs possess power-law degree sequences with a power-law exponent \tau>2. We prove that the diameter of the PA-model is bounded above by a constant times \log{t}, where t is the size of the graph. When the power-law exponent \tau exceeds 3, then we prove that \log{t} is the right order, by proving a lower bound of this order, both for the diameter as well as for the typical distance. This shows that, for \tau>3, distances are of the order \log{t}. For \tau\in (2,3), we improve the upper bound to a constant times \log\log{t}, and prove a lower bound of the same order for the diameter. Unfortunately, this proof does not extend to typical distances. These results do show that the diameter is of order \log\log{t}. These bounds partially prove predictions by physicists that the typical distance in PA-graphs are similar to the ones in other scale-free random graphs, such as the configuration model and various inhomogeneous random graph models, where typical distances have been shown to be of order \log\log{t} when \tau\in (2,3), and of order \log{t} when \tau>3

Fabry-betegség – terápiás útmutató

A Fabry-kór a lizoszomális tárolási betegségek csoportjába tartozó, X-kromoszómához kötötten, recesszív módon öröklődő betegség, amely a globotriaozilceramid felhalmozódásához vezet a szervezet legkülönbözőbb szöveteiben. A betegség első tünetei többnyire gyermekkorban jelentkeznek, a progresszió során a betegek súlyos szervi károsodásokkal és korai halálozással számolhatnak. Elsősorban férfiak érintettek, azonban a betegség tüneteit heterozigóta nők esetében is megfigyelhetjük, de náluk a kórkép súlyossága változó, általában enyhébb lefolyású. Az enzimpótló kezelések megjelenése szükségessé tette, hogy részletes diagnosztikus és terápiás protokollt dolgozzunk ki. A jelen dolgozatban megjelenő ajánlásokat egy, a magyarországi Fabry-kóros betegek kezelésében részt vevő orvosokból, a diagnosztika területén dolgozó biológosukból és egyéb szakemberekből álló multidiszciplináris munkacsoport foglalta össze. A munkacsoport áttekintette a korábbi klinikai tanulmányokat, a publikált vizsgálatokat és a közelmúltban megjelent nemzetközi és nemzeti útmutatókat. | Fabry disease is a rare, X-linked lysosomal storage disorder that leads to accumulation of globotriaosylceramide in different tissues of the body. The disease is progressive and the first symptoms usually present in childhood. Consequences of the disease are disability and premature death. The disease in females could be as severe as in males although women may be asymptomatic. The possibility of enzyme replacement therapy has made it necessary to elaborate a comprehensive guideline for the diagnosis and treatment follow-up. The guideline has been summarized by a Hungarian multi-disciplinary working group consisting of physicians who are involved in diagnosis and care of Fabry patients. Previous clinical studies, published articles, and recently established international treatment guidelines were reviewed by the group

Fabry-betegség - Diagnosztikai útmutató

A Fabry-kór a lizoszomális tárolási betegségek csoportjába tartozó, X-kromoszómához kötötten, recesszív módon öröklődő betegség, amely a globotriaosylceramid felhalmozódásához vezet a szervezet legkülönbözőbb szöveteiben. A betegség első tünetei többnyire gyermekkorban jelentkeznek, a progresszió során a betegek súlyos szervi károsodásokkal és korai halálozással számolhatnak. Elsősorban fiúk és férfiak érintettek, azonban a betegség tüneteit heterozigóta nők esetében is megfigyelhetjük, de náluk a kórkép súlyossága változó, általában enyhébb lefolyású. Az enzimpótló kezelések megjelenése szükségessé tette, hogy részletes diagnosztikus és terápiás protokollt dolgozzunk ki. A jelen dolgozatban megjelenő ajánlásokat egy, a magyarországi Fabry-betegek kezelésében aktívan részt vevő orvosokból, a diagnosztika területén dolgozó biológosukból és egyéb szakemberekből álló multidiszciplináris munkacsoport foglalta össze. A munkacsoport áttekintette a korábbi klinikai tanulmányokat, a publikált vizsgálatokat és a közelmúltban megjelent nemzetközi és nemzeti útmutatókat. | Fabry disease is a rare, X-linked lysosomal storage disorder that leads to accumulation of globotriaosylceramide in different tissues of the body. The disease is progressive, first symptoms usually present in childhood. Consequencies of the diseases are disability and premature death. The disease in females could be as severe as in males although women may also be asymptomatic. The possibility of enzyme replacement therapy has made it necessary to elaborate a comprehensive guideline for the diagnosis and treatment follow-up. The guideline was established by a Hungarian multi-disciplinary working group, consisting of physicians who are involved in health care of Fabry patients. Previous clinical studies, published materials, and recently established international treatment guidelines were reviewed by the group

Does the disturbance hypothesis explain the biomass increase in basin-wide Amazon forest plot data?

Positive aboveground biomass trends have been reported from old-growth forests across the Amazon basin and hypothesized to reflect a large-scale response to exterior forcing. The result could, however, be an artefact due to a sampling bias induced by the nature of forest growth dynamics. Here, we characterize statistically the disturbance process in Amazon old-growth forests as recorded in 135 forest plots of the RAINFOR network up to 2006, and other independent research programmes, and explore the consequences of sampling artefacts using a data-based stochastic simulator. Over the observed range of annual aboveground biomass losses, standard statistical tests show that the distribution of biomass losses through mortality follow an exponential or near-identical Weibull probability distribution and not a power law as assumed by others. The simulator was parameterized using both an exponential disturbance probability distribution as well as a mixed exponential–power law distribution to account for potential large-scale blowdown events. In both cases, sampling biases turn out to be too small to explain the gains detected by the extended RAINFOR plot network. This result lends further support to the notion that currently observed biomass gains for intact forests across the Amazon are actually occurring over large scales at the current time, presumably as a response to climate change