Precise control of flexible manipulators

The design and experimental testing of end point position controllers for a very flexible one link lightweight manipulator are summarized. The latest upgraded version of the experimental set up, and the basic differences between conventional joint angle feedback and end point position feedback are described. A general procedure for application of modern control methods to the problem is outlined. The relationship between weighting parameters and the bandwidth and control stiffness of the resulting end point position closed loop system is shown. It is found that joint rate angle feedback in addition to the primary end point position sensor is essential for adequate disturbance rejection capability of the closed loop system. The use of a low order multivariable compensator design computer code; called Sandy is documented. A solution to the problem of control mode switching between position sensor sets is outlined. The proof of concept for endpoint position feedback for a one link flexible manipulator was demonstrated. The bandwidth obtained with the experimental end point position controller is about twice as fast as the beam's first natural cantilevered frequency, and comes within a factor of four of the absolute physical speed limit imposed by the wave propagation time of the beam

Interpersonal sensorimotor contingencies: Information-theoretic relevance of subjective experience

Peer reviewedFinal Published versio

Design of Sievenpiper HIS for use in planar broadband antennas by means of effective medium theory

The claim for multistandard operating handsets of small physical size as well as the ever increasing demand for higher data rates require new broadband operating antennas. Because of the widespread use of especially planar broadband antennas a lot of factors influencing the characteristic antenna parameters have to be regarded. Furthermore, aspects regarding the electromagnetic compatibility inside the handheld as well as the protection of biological systems, e.g. the user of a mobilephone, have to be payed attention to. An electromagnetic structure which allows for protection by means of shielding as well as enhances the antennas efficiency by providing unique electromagnetic properties are the so called Sievenpiper High Impedance Surfaces (HIS) invented by Sievenpiper (1999). This paper will present the theory and the well known design equations for those structures. An investigation by means of simulation tools and measurement setups will be done to approve the accuracy of the theoretical results. Here measurement results of the impedance and radiation properties of a planar log.-per. fourarm antenna equiped in conjunction with a fabricated prototype Sievenpiper HIS will be presented

Sievenpiper HIS and its influence on antenna correlation

This paper deals with the influence of artificial magnetic conductors (AMC), so-called Sievenpiper High Impedance Surfaces (HIS), on the MIMO and Diversity performance of a planar linear-polarized 2×2 dipole array in the ISM-band at 2.45 GHz. The characteristic performance criteria such as envelope correlation coefficient, spectral efficiency, Mean Effective Gain (MEG) and Diversity gain of a coupled 2×2 dipole array are investigated. By means of full-wave electromagnetic analysis as well as Monte-Carlo simulations applying statistical channel models the characteristic antenna pattern just as the MIMO and Diversity analysis is performed, respectively. The obtained results show that the application of Sievenpiper High Impedance Surfaces to planar antenna arrays enables good MIMO and Diversity performance compared to ideal configurations in free-space while offering the design of low profile antennas with simultaneously enhanced characteristics. © Author(s) 2008

Роль генетического компонента предрасположенности к раку молочной железы у женщин различных этнических групп населения Крыма

Результаты клинико-генеалогического и генетико-математического методов исследования 57 здоровых и 214 больных раком молочной железы (РМЖ) женщин показали, что частота заболевания злокачественными новообразованиями родственников I степени родства пациентов с РМЖ как крымско-татарской, так и славянских этнических групп более высокая (10,44%), чем в крымской популяции в целом (7,36%). Возникновение РМЖ у женщин крымско-татарской этнической группы в большей мере обусловлено генетической предрасположенностью к злокачественному росту по сравнению со славянской группой, о чем свидетельствуют появления РМЖ в более молодом возрасте как у пробандов-татарок, так и их родственниц (53,4 ± 3,6 и 46,5 ± 11,2 года соответственно в сравнении с 59,8 ± 1,9 и 54,9 ± 8,3 года у славянок), более частое развитие РМЖ у родственниц татарок (48,3 ± 11,1 против 25,6 ± 6,6%), более высокая соотносительная доля наследственных факторов в возникновении рака (генетический компонент 58,5 против 44,5%, р 0,05). Ключевые слова: этнические особенности, злокачественные новообразования, рак молочной железы, наследственность.A clinical/genealogical and genetic mathematic study of 57 healthy subjects and 214 breast cancer (BC) patients showed that malignant neoplasm is more frequent in immediate (degree 1) relatives of BC patients in both Crimean Tartar and Slavic populations compared to the general population (10.44% versus 7.36% respectively). In the Crimean Tartar population, genetic burden plays a more considerable role in BC frequency compared to the Slavic population. This conclusion is based on a number of findings, including: younger age of BC manifestation in both probands and their relatives (53.4 ± 3.6 and 46.5 ± 11.2 in Tartars versus 59.8 ± 1.9 and 54.9 ± 8.3 in Slavs), higher frequency of BC in relatives (48.3 ± 11.1 versus 25.6 ± 6.6% respectively), higher correlative share of genetic factors in the development of malignancy (genetic component: 58.5 against 44.5%, р 0.05). Key Words: ethnic specifics, malignancy, breast cancer, hereditation

Considering even-order terms in stochastic nonlinear system modeling with respect to broadband data communication

As a tradeoff between efficiency and costs modern communication systems contain a variety of components that can at least be considered weakly nonlinear. A critical element in evaluating the degree of nonlinearity of any underlying nonlinear system is the amount of undesired signal strength or signal power this system is introducing outside the transmission bandwidth. This phenomenon called spectral regrowth or spectral broadening is subject to stringent restrictions mainly imposed by the given specifications of the particular communication standard. Consequently, achieving the highest possible efficiency without exceeding the linearity requirements is one of the main tasks in system design. Starting from this challenging engineering problem there grows a certain need for specialized tools that are capable of predicting linearity and efficiency of the underlying design. Besides a multitude of methods aiming at the prediction of spectral regrowth a statistical approach in modeling and analyzing nonlinear systems offers the advantage of short processing times due to closed form mathematical expressions in terms of input and output power spectra and is therefore further examined throughout this article

Spacelab 3: Research in microgravity

The Spacelab 3 mission, which focused on research in microgravity, took place during the period April 29 through May 6, 1985. Spacelab 3 was the second flight of the National Aeronautics and Space Administration's modular Shuttle-borne research facility. An overview of the mission is presented. Preliminary scientific results from the mission were presented by investigators at a symposium held at Marshall Space Flight Center on December 4, 1985. This special issue is based on reports presented at that symposium

Evidence against protein kinase B as a mediator of contraction-induced glucose transport and GLUT4 translocation in rat skeletal muscle

AbstractBoth insulin and muscle contraction stimulate glucose transport activity. However, contraction stimulation does not involve the insulin signalling intermediate phosphatidylinositol 3-kinase (PI 3-kinase). Protein kinase B (PKB) has recently been identified as a direct downstream target of PI 3-kinase in the insulin signalling pathway. We have examined here whether the two stimuli share PKB as a convergent step in separate signalling pathways. Insulin stimulates both glucose transport, GLUT4 cell-surface content and PKB activity (by 4–6-fold above basal) in a wortmannin-sensitive manner in in vitro incubated rat soleus muscles. By contrast, muscle contraction, which stimulates glucose transport and the cell surface content of GLUT4 by 3-fold above basal levels, had no effect on PKB activity. These data demonstrate that PKB is not a mediator of contraction-induced glucose transport and GLUT4 translocation