Showing papers by "Münster University of Applied Sciences published in 2010"

The permease gene nagE2 is the key to N-acetylglucosamine sensing and utilization in Streptomyces coelicolor and is subject to multi-level control.

Abstract: The availability of nutrients is a major determinant for the timing of morphogenesis and antibiotic production in the soil-dwelling bacterium Streptomyces coelicolor. Here we show that N-acetylglucosamine transport, the first step of an important nutrient signalling cascade, is mediated by the NagE2 permease of the phosphotransferase system, and that the activity of this permease is linked to nutritional control of development and antibiotic production. The permease serves as a high-affinity transporter for N-acetylglucosamine (K(m) of 2.6 microM). The permease complex was reconstituted with individually purified components. This showed that uptake of N-acetylglucosamine requires a phosphoryl group transfer from phosphoenolpyruvate via the phosphotransferases EI, HPr and IIA(Crr) to NagF, which in turn phosphorylates N-acetylglucosamine during transport. Transcription of the nagF and nagE2 genes is induced by N-acetylglucosamine. Nutrient signalling by N-acetylglucosamine that triggers the onset of development was abolished in the nagE2 and nagF mutants. nagE2 is subject to multi-level control by the global transcription factor DasR and the activator AtrA that also stimulates genes for antibiotic actinorhodin biosynthesis. Hence, it is apparent that streptomycetes tightly control the nutritional state in a complex manner to ensure the correct timing for the developmental programme.

Actuator patterns for unimorph and bimorph deformable mirrors

Abstract: The actuator pattern of an adaptive mirror determines the amplitudes and the fidelities of the mirror deformations that can be achieved In this study, we analyze and compare different electrode patterns of piezoelectric unimorph deformable mirrors using a numerical finite element model The analysis allows us to determine the optimum actuator pattern, and it is also applicable to bimorph mirrors The model is verified by comparing its predictions with experimental results of our prototype of a novel unimorph deformable mirror

Potential of nano-ZnS as electrocatalyst.

Abstract: ZnS is a versatile wide-gap semiconductor that shows remarkable chemical stability against oxidation and hydrolysis. These properties are retained when the particle size steps down to 10 nm and below, and thus ZnS nanoparticles are interesting entities for optical and catalytic functions, where they might be exposed to quite aggressive environments. Moreover, ZnS may be doped by a host of elements, so that the electrical and optical properties can be tuned over an extended range. Neither Zn nor S are in short supply, and ZnS as compound or in view of the constituting elements is not toxic. Therefore, functional materials based on ZnS will be ideal for "green chemistry" applications, since they are suited also for large scale manufacture and will pose no additional problems when released into the environment. The article describes first results for ZnS-nanoparticles acting as electrocatalysts, a field that has not been covered so far by ZnS-derived materials. The catalytic action is evaluated for the decomposition of ethanol, a potentially abundant fuel for mobile electricity generation, since it can be fabricated by fermentation from a broad range of organic materials.

Exploiting the icon arrangement on mobile devices as information source for context-awareness

Abstract: The contextual relevance of a service can only be determined by the human himself. However, a measure for relevance is required for context-aware service delivery. In this paper, we draw attention to icon arrangement on mobile devices as a new source of information for adaptive menus. We conducted contextual inquiries to investigate how people arrange icons on a grid-based menu. Our results show that context has an impact on how users arrange their menus: during different activities they prefer different icons to be placed at specific positions. We discuss layout options for icon menus and argue how the relevance can be approximated by observing the icon arrangement. Our results informed the design of a context-aware client for mobile services, which is presented as a prototype.

Synthesis and Properties of Tetracyanamidosilicates ARE[Si(CN2)4]

Abstract: Tetracyanamidosilicates of the type ARE[Si(CN2)4] with A = K, Rb, and Cs and RE = Y and La−Lu have been prepared by a solid-state metathesis reaction. The potassium compounds with RE = La−Gd crystallize orthorhombically in the space group P21212. Rubidium as well as cesium compounds crystallize tetragonally in the space group I4. The luminescent properties of ARE[Si(CN2)4]:Ln compounds with RE = Y, La, and Gd doped with 5 mol % Ln = Ce, Eu, or Tb were investigated. Temperature-dependent magnetic susceptibilities were measured for KGd[Si(CN2)4]. The value of the magnetic moment is 7.3 μB/Gd3+ ion, which is in line with the expected value for the [Xe]4f7 configuration of Gd3+.

A partnering business model for technology transfer: the case of the Muenster University of Applied Sciences

Abstract: Theory and practice of technology transfer and entrepreneurial behaviour of academics are novel. We draw upon the literature of business models, transaction costs, professional and organisational culture and of agency theory to formulate a framework for a technology transfer business model. We present the range of options used by universities and we examine the spin out option, as context and contrast to the MUAS approach. The case of the MUAS is presented. It illustrates the conceptual framework developed and has thus far been successful in its specific environment. Replication might require adaptation, but this particular approach can offer useful lessons. Tentative hypotheses for research on business model adaptation are derived from the study.

Integration of SCTP in the OMNeT++ Simulation Environment

Abstract: The INET framework for the widely used OMNeT++ simulation environment supports discrete event simulation for IP-based networks. This paper describes an implementation of the Stream Control Transmission Protocol (SCTP) within this framework. SCTP is a new transport protocol originally designed for signaling transport in telephony networks. The simulation model and parameters of the SCTP implementation in INET are discussed in detail. The INET framework has also been extended to support external interfaces. These interfaces allow to set up hybrid scenarios where simulated nodes communicate with real external IP-based nodes. This new feature was used to test the simulation against multiple SCTP implementations at the last SCTP Interoperability tests. Other methods that were used to verify the SCTP simulation are finally discussed.

Interface connecting the INET simulation framework with the real world

Abstract: The INET framework for the widely used OMNeT++ simulation environment supports discrete event simulation for IP-based networks. During the development of a simulation model for the new IETF transport protocol SCTP (Stream Control Transmission Protocol), INET was extended to also support external interfaces. These interfaces allow to set up hybrid scenarios where simulated nodes communicate with real external IP-based nodes. This paper will first give a short introduction to the OM-NeT++ simulation environment and the INET framework. Then the requirements for the external interfaces will be discussed and some implementation aspects will be described. Hybrid scenarios offer a whole range of potential applications which will also be presented briefly. The performance of this technique is crucial for its applicability. Therefore, several test setups are evaluated to verify the feasibility of this approach.

Stream scheduling considerations for SCTP

Abstract: The Stream Control Transmission Protocol (SCTP) supports multiple streams to minimize head-of-line blocking. This requires a scheduler for sending and receiving messages of different streams, but the specification of SCTP does not make any statement regarding their implementation. Hence, after examining the possibilities, we show that several standard scheduling algorithms are a benefit when used in specific scenarios and also introduce per packet scheduling as a new method to minimize end-to-end delays. Furthermore, we describe how priority scheduling allows to realize a flow control for every stream without changes to the SCTP protocol, thus allowing the receiver to control the throughput of each stream.

Theory of the simple genetic algorithm with α-selection, uniform crossover and bitwise mutation

Abstract: Genetic algorithms (GA) are instances of random heuristic search (RHS) which mimic biological evolution and molecular genetics in simplified form. These random heuristic search algorithms can be theoretically described by an infinite population model with the help of a deterministic dynamical system model by which the stochastic trajectory of a population can be characterized using a deterministic heuristic function and its fixed points. For practical problem sizes the determination of the fixed points is unfeasible even for the simple genetic algorithm (SGA) with fitness-proportional selection, crossover and bitwise mutation. The recently introduced simple genetic algorithm with α-selection allows the analytical calculation of the unique fixed point of the corresponding intrinsic system model. In this paper, an overview of the theoretical results for the simple genetic algorithm with α-selection and its intrinsic system model is given. The unique fixed point of the intrinsic system model is derived and its compatibility with the equivalence relation imposed by schemata is shown. In addition to the theoretical analysis experimental results for the simple genetic algorithm with α-selection, uniform crossover and bitwise mutation are presented showing a close agreement to the theoretical predictions.

Schmerz und Bewegungsangst im Alter

Abstract: Eine korperlich-aktivierende Therapie ist auch bei chronischen Schmerzen im Alter leitliniengerecht und wichtig zur Erhaltung der Selbststandigkeit. Altere Schmerzpatienten sind jedoch oft nur schwer fur diese Verfahren zu gewinnen, was mit ungunstigen Einstellungen, geringer Selbstwirksamkeit, Schmerz- und Sturzangsten zusammenhangt. Sturzangste spielen bei der Reduzierung der Aktivitat bei Schmerzpatienten womoglich eine bedeutsamere Rolle als die aus der Schmerzforschung bekannten „fear avoidance beliefs“. Auch die Angstlichkeit der Pflegenden kann zu einer Aktivitatseinschrankung der Alteren fuhren. Grunderkrankungen und Medikamentenwirkungen mussen bei bewegungsorientierten Therapien beachtet werden. Es erscheint notig, spezielle Therapiebausteine fur alle Versorgungssektoren zu entwickeln, dabei altersspezifische Motivationsstrategien einzubauen und sich gut interdisziplinar abzustimmen.

Parallelizing OMNeT++ Simulations using Xgrid

Abstract: Working with simulations, testing and validating theories often requires a large number of simulation runs. The discrete event simulation environment OMNeT++ already provides functionality for distributed computing, yet the simulated model and modules to be parallelized have to be declared manually. Apple Mac OS X comes with Xgrid support, which allows easily setting up an ad hoc grid for parallel computing. In this paper we will describe the features we had to add to OMNeT++ to be able to use Xgrid to parallelize even several thousand runs. We will point out how to use Xgrid to distribute runs of a simulation not only to multiple CPU cores but also to multiple machines without modifying the simulation itself. Our analysis will reveal that Xgrid allows to reduce the computing time almost proportional to the added parallel computing power.

Medienpädagogische Kompetenz in der Sozialen Arbeit

Abstract: Man konnte meinen, die heutige Medientechnik sei kompetent geworden. Aber dieser Sprachgebrauch ware irritierend, weil Technik zwar etwas kann, aber nichts weis; kompetent sind Menschen, nicht Sachen. Kompetenz von Menschen ist relativ, aber in unserer von wirtschaftlichem Kalkul dominierten Gesellschaft sehr gefragt. Doch dies gilt nicht fur jede Art von Kompetenz gleichermasen. Sie muss schon gewinnbringend sein. Die meisten Kompetenzen beispielsweise, die in der TV-Show „Wetten dass“ prasentiert werden, sind auserhalb des Sendeformats und Showeffekts wenig nutzlich. Und es ist legitim zu fragen, wozu die unbestreitbaren Kompetenzen eines versierten Computerspielers taugen. Kompetenz ist ein abstrakter und fur sich leerer Begriff. Wer gefragt wird, ob er kompetent ist, wird vermutlich mit einer Gegenfrage nach dem Gegenstand der Kompetenz fragen oder ausweichend antworten: „Kommt darauf an …“. Wann ist jemand in Bezug auf einen Sachverhalt oder in einem bestimmten Bereich kompetent? Gehort dazu eher Konnen oder Wissen oder beides, gehoren z.B. auch Entscheidungsbefugnis, Mut etwas zu tun und moralische Haltung bzw. Verantwortung und ein sinnvoller Anwendungsbezug oder gar Abweichen vom Gewohnlichen und Normalen dazu?

Understanding the Advisory Needs of Citizens

Abstract: For several years the public sector has experienced substantial changes. First the widespread use of the Internet and the e-government discussion led to an extended offer of information for each governmental level (federal, state, regional, local) of the public authorities and a broad offer of online applications. The recent discussion of citizen-centred e-government focuses on governmental services and resources tailored to the actual needs of users including citizens, residents, government employees and others. Secondly, New Public Management supported the perception of citizens being customers which resulted in major changes e.g. long opening hours, centralized citizen offices. Despite these improvements citizens still don‟t perceive public services as customer centred and helpful in all aspects of life especially in complex ones like having a baby or moving to another city. Strict division of labour, protection of data privacy and fragmented databases in the public sector encourage this perception. The work described in this article is the first step to a citizen-centred e-government application which combines online and offline components to generate an “all around” service including information, planning and organization. It focuses on the understanding of the need for citizen advisory. To get insight and overview of the field of advisory as well as advisory, as well as advisory in public administration, we started with literature research (see 2.). Based on this, field research followed to gain further experience and knowledge (see 4.). Both steps lead to the results (see 5.) with design requirements for an information system supporting citizens‟ advisory in public administration.

Luminescence properties of Eu 3+ and Ti IV /Zr IV doped yttrium oxysulfides (Y 2 O 2 S:Eu 3+ ,Ti IV /Zr IV )

Abstract: The red emitting Y2O2S:Eu3+,TiIV (or ZrIV, xEu: 001, xTi/Zr: 0003/0015/003) materials were prepared with a flux method According to X-ray powder diffraction, the materials have the hexagonal crystal structure The UV excited (λexc: 250 nm) emission maximum was observed at 628 nm due to the 5D0→7F2 transition of Eu3+ The excitation spectra (λem: 628 nm) consist of broad bands centered at 240 and 320 nm due to the charge transfer transitions O2−→Eu3+ and S2−→Eu3+, respectively Red persistent luminescence was observed with a maximum at 628 nm, as well Persistent luminescence was the strongest with the TiIV co-doping though the intensity of persistent luminescence decreased with the increasing amount of both the TiIV and ZrIV co-dopants The thermoluminescence (TL) glow curves of the Y2O2S:Eu3+,TiIV materials consist of bands at ca 110 and 200 °C In Y2O2S:Eu3+,ZrIV, similar bands are observed at lower temperatures viz at ca 100 and 180 °C TL weakens when the amount of co-dopants is increased The TiIV co-doped materials have stronger TL than the ZrIV co-doped materials The deconvolution of TL glow curves revealed three distinct traps with depths ranging from 06 to 10 eV

Pixel advisor: An expert system for the ATLAS pixel detector control system

Abstract: Since December 2009, the Large Hadron Collider (LHC) and its four main experiments are taking physics data. Each of those four experiments consists of sub-detectors, which are responsible for energy, momentum and particle trajectory measurements. As the innermost sub-detector of the ATLAS experiment, the Pixel detector provides precise measurements of momenta and trajectories of charged particles, which are for example needed to identify and separate the primary and secondary vertices. The ATLAS Pixel detector makes high demands on its control system, as more than 30000 parameters like voltages, currents and temperatures have to be monitored and controlled “twenty-fourseven”. Several software control and automation layers including a finite state machine are employed to filter the incoming information and provide a clear detector user-interface. In addition, these software layers allow for detector operation by the use of just a few buttons under default conditions. While the multi-layered user-interface of the control system software, which is based on the PVSS supervisory control and data acquisition system, enables normal detector operation by trained shifters, expert knowledge is still needed to solve problems that arise. In addition to the available on-call experts, a Java JBoss-Rules based expert system called “Pixel Advisor” has therefore been developed to provide help in solving error conditions. The presented paper describes the basic principles of this expert system and the first experience from its use.

Method for separation of carbon dioxide from gaseous mixture and/or flow of gas for use in e.g. oil refinery, involves contacting gaseous mixture and/or gas stream with mixture containing amidine, water and aprotic solvent

Abstract: The method involves contacting gaseous mixture and/or gas stream with a mixture containing an amidine, water and aprotic solvent e.g. dialkyl ether, containing an ether and/or ester group such that a partially insoluble amidine-carbon-dioxide adduct or reaction product is provided as outcome. The amidine and the water are provided in a specific ratio before contacting carbon-dioxide, and the reaction product is separated.

The intrinsic system model of the simple genetic algorithm with α-selection, uniform crossover and bitwise mutation

Abstract: Genetic algorithms (GA) are instances of random heuristic search (RHS) which mimic biological evolution and molecular genetics in simplified form. These random search algorithms can be theoretically described with the help of a deterministic dynamical system model by which the stochastic trajectory of a population can be characterized using a deterministic heuristic function and its fixed points. For practical problem sizes the determination of the fixed points is unfeasible even for the simple genetic algorithm (SGA). The recently introduced simple genetic algorithm with α-selection allows the analytical calculation of the unique fixed point of the corresponding intrinsic system model. In this paper, an overview of the theoretical results for the simple genetic algorithm with α-selection and its intrinsic system model is given. In addition to the theoretical analysis experimental results for the simple genetic algorithm with α-selection, uniform crossover and bitwise mutation are presented.

Bedarfsermittlung und Informationsaggregation bei der Bürgerberatung 2.0

Abstract: In komplexen Lebenslagen benotigen Burger selbst in Zeiten des Internets eine personliche Beratung. In Mystery Shoppings zeigte sich, dass die Kommunen bisher keinem strukturierten Beratungsprozess folgen, wie man ihn von kommerziellen Dienstleistern kennt. In diesem Paper wird der in dem Pilotprojekt Burgerberatung 2.0 entwickelte Burgerberatungsprozess vorgestellt. Dieses Paper konzentriert sich dabei auf zwei Phasen des Prozesses: Die Bedarfserhebung und die Informationsaggregation. Eine Bedarfserhebung ist in komplexen Lebenslagen notwendig, wenn Burger zwar ihre Situation beschreiben, aber mangels Vorwissen nicht gezielt Fragen stellen konnen. Die Informationsaggregation fugt die in einer Suche gefundenen Einzelinformationen so zu einem Gesamtbild, dass der Burger dann auch handlungsfahig ist. Hierfur wird ein Strukturierungsansatz der relevanten Informationen zu IT-gestutzter Burgerberatung fur das Beispiel der Beratung schwangerer Frauen vorgestellt. Diese Informationsstrukturen wurden in einem Prototyp umgesetzt und in einer deutschen Kommune evaluiert. Die durchgehend positiven Evaluierungsergebnisse deuten darauf hin, dass Burgerinnen eine Burgerberatung handlungsfahig verlassen, wenn die Ergebnisse einer gemeinsamen Informationssuche mit dem Berater nach den funf Strukturierungsdimensionen „Themen“, „Orte“, „Zeit“, „Ressourcen“ und „Aktivitat“ aggregiert werden.

CO2-Absorptionsverfahren mittels Aminlösungen

Abstract: Die vorliegende Erfindung bezieht sich auf die Abtrennung von CO 2 aus Gasgemischen durch Ausfallen eines Amin-CO 2 -Addukts, welches ggf. bei niedrigen Temperaturen das CO 2 wieder freisetzt.

Laryngeally echolocating bats

Abstract: Arising from: N. Veselka et al. , 939–942 (2010)10.1038/nature08737 ; Veselka et al. reply Echolocation of bats is a fascinating topic with an ongoing controversy regarding the signal processing that bats perform on the echo. Veselka et al.1 found that bats that use the larynx for producing the echolocating ultrasound have a stylohyal bone that connects the larynx to the auditory bulla. I propose that the stylohyal bone is used for heterodyne detection of Doppler-shifted echoes. This would allow very precise frequency resolution and phase-sensitive analysis of the returning echoes for determining the velocity of echolocated objects like insects.

Nachweis von Strukturdefekten in Elementwänden mittels zerstörungsfreier Prüfverfahren

Abstract: Der Beitrag befasst sich mit der Nachweisbarkeit von Strukturdefekten in Elementwanden mittels zerstorungsfreier Prufverfahren. Innerhalb einer Versuchsreihe wurden in Elementwanden vordefinierte Fehlstellen eingebaut, die wahrend der Betonage auf der Baustelle auftreten konnen. Die Messungen wurden durch verschiedene Messteams mit Ultraschall-Echo-, Impact-Echo- und Impuls-Radar-Verfahren an einem vorgegebenen Messraster ausgefuhrt. Dabei konnten die Strukturdefekte vielfach zerstorungsfrei nachgewiesen werden. Die wesentlichen Untersuchungsergebnisse werden nachfolgend dargestellt. Verification of Failure in Prefabricated Walls Using Non-Destructive Testing Methods This essay deals with the verification of failure in prefabricated walls using non-destructive testing methods. Series of tests were carried out considering several imperfections which might occur on site during construction. Three measuring methods were used by different parties to carry out the tests. These methods were the Ultrasonic Echo Method, the Impact-Echo Method and Impulse Radar Technique, where in many cases failure could have been detected in using these methods. The main research results are presented here.

Design IT-gestützter kooperativer Bürger-Beratung

Abstract: Bereits vor Durchbruch des Internets bestanden Bürger-Büros in Britischen Kommunen zur Beratung und Hilfestellung von Bürgern (Citron 1989). Da Leistungen durch die Regierung gewährt wurden, war es den Kommunen ein Anliegen, ihre Bürger mit bestmöglicher Beratung zur Beantragung dieser auszustatten. So analysierte Whitaker (1980) den Wert von Lösungen, die in Co-Produktion von Bürger und Berater erstellt wurden. Die aufkommende Nutzung und Verbreitung von Internet und Web führten jedoch zu einer Verlagerung der Diskussion Mitte der 90er Jahre. „Bürgerinformation“ war der neue Fokus, da drastisch besserer Zugang zu relevanten Informationen über das Web erwartet wurde. Nach mehr als einer Dekade der Bereitstellung von Informationen über das Internet werden auch die Grenzen diese Kanals deutlich: Das Internet setzt voraus, dass der Bürger weiß, wonach er suchen muss (Belkin 1982). Komplexe Informationsanliegen bedeuten, dass die Betroffenen nicht in der Lage sind, ihren Informationsbedarf effektiv zu formulieren, bis sie eine gewisse Vorstellung über die Antwort entwickelt haben und wissen, welche Rahmenbedingungen hierfür relevant sind. Dies ist aber gerade in komplexen Lebenslagen häufig nicht der Fall. In diesem Fall ist der Bürger weiterhin auf persönliche Beratung und Fähigkeit der Beratenden angewiesen, zu fragen, Verständnis abzuklären und Rückmeldung zu geben. Während die Beratungstätigkeit selbst in der Literatur diskutiert wird (z. B. Mutzeck (2005), Hielscher und Ochs (2009)), wird deren Unterstützung durch IT bisher in der EGovernment-Literatur nur am Rande behandelt (z. B. Lenk und Klee-Kruse 2000). Im Forschungsprojekt "Bürgerberatung 2.0" setzten wir uns deshalb zum Ziel, die Interaktion zwischen Beratern und Bürgern mit Hilfe von IT zu verbessern. In diesem Beitrag geht es darum, drei Kernaspekte des Systemdesigns zu beleuchten:

Assistentenmotivation und -zufriedenheit in der Urologie

Abstract: To address the increasing shortage of qualified residents, which leads to further discontent and additional on-call rotations for the remaining physicians, an analysis of the current situation was performed. Stress in the daily working routine, not enough free time, too little pay, or too little compensatory time off for overtime as well as inadequate options for continuing education were reported to be the main elements of dissatisfaction. The economic pressure of day-to-day work continues to define the physician's role and places demands on the medical staff by burdening them with nonmedical and administrative tasks.The major causes mentioned were staff shortage and lack of support provided by supervisors and the administration. For this reason, human resource development should be considered a strategic and central goal. This requires a normative, cross-functional approach at all levels of management and inclusion of personnel departments in the strategic processes of the hospital. The most important aspects for resident satisfaction were the work environment, acceptable work-life balance and remuneration, compensation for overtime, and quality of available continuing education, which is often rated as being insufficient.Effective strategies to improve the motivation of residents comprise offering opportunities for structured continuing education, optimizing the everyday work processes, and involving employees in social networks. The establishment of feedback strategies, including recognition of residents' achievements, will help to ensure their loyalty and identification with their clinic. This can serve as a preventive measure to offset any potential willingness to change jobs.

Simulation of the complex countermovement jumping by means of a simple four-degrees-of-freedom model

Abstract: By means of a four-degrees-of-freedom model the vertical movements of an athlete and the time course of the ground reaction force were simulated during a countermovement jump on a concrete and a wooden surface. The model masses were connected to each other and to the surface by springs and dampers. At first the stiffness of the springs decreased in order to initiate the countermovement. Afterwards the stiffness increased like the muscle activity so that the flexion of the model ‘legs’ were decelerated before the extension starts. The best result was attained when the stiffness of the spring between the model masses ‘thighs’ and ‘trunk’ increased before the other three springs. Compared with the muscle activity this means that for a successful jump the upper body segments have to be accelerated before the segments near to the ground are accelerated. The model ‘athlete’ was connected to a model of the surface. It could be shown that the jump on a concrete surface results in a better jump height than the jump on an elastic wooden surface if the muscle activation is not adapted to the surface properties.

Reliable and Energy Optimized Routing Algorithm for WSNs

Abstract: Benefits like elimination of hard-wiring, cost reduction, infrastructure-free and easy maintenance make Wireless Sensor Networks (WSNs) an innovative technology whose range of applications is increasing in many different environments. Since WSNs were born, reliable communications have been a challenge. Some complex routing solutions have been presented in the recent past. In this paper, the objective is to present a simple algorithm to enhance the reliability of end-to-end transmissions optimizing power consumption and to demonstrate that it works in applications that require bounded delay guarantees on packet delivery.

A New Combined Optical and Robotic Testing System to Evaluate Multisegmental Spinal Kinematics

Abstract: A testing system was developed with the aim of evaluating in vitro kinematics of multisegmental spine specimens. This includes a robot (KUKA-KR125) and an optical tracking system (NDI, Optotrak-Certus) measuring the three-dimensional kinematics of each vertebral body simultaneously. The robot has the option of saving kinematic and force/torque (F/T) data for repeating a prerecorded motion path. It can apply unconstrained physiologic movement. In a first evaluation study the robots’ F/T control unit was conducted using a linear rod with a second F/T load cell in-line. Kinematic accuracy of the tracked optical data and the calculation software was determined. The study was complemented by testing six four-segmental lumbar calf specimens (L2-6). Three cycles of pure unconstrained moments (7.25±0.05Nm) were applied to each specimen in flexion-extension. Robot data and optical system records were synchronized using a self-developed software algorithm. For each spinal segment load-displacement data were analyzed for range of motion (ROM), neutral zone (NZ) and elastic zone (EZ). In addition the finite helical axes (FHA) for spinal segment motions were calculated. For each level ROM was compared to literature values from monosegmental studies matching with 102±17.6% for L2-3 to 101±15.7% for L5-6 of used reference. Segmental stiffness ranged from 0.3±0.14 to 0.7±0.14Nm/° for NZ and from 2.7±0.55 to 4.9±1.79Nm/° for EZ. Position and orientation of the inter-segmental FHA varied significantly for each segment and specimen. In general, the precision of the robot system seems to be adequate and the results are consistent with intact monosegmental data from literature. Therefore the testing system can be used to investigate adjacent level effects including coupled motion in a multisegmental specimen in future experiments.

Influence of Pipe-Junctions on Downstream Measuring Sections, predicted by a numerical model

Abstract: Measuring discharge data in sewer networks serves to optimize planning and operation processes of water management in the urban sewer system, treatment plants and rivers. The efficiency of a measuring campaign is strongly dependent on positioning of the measuring section in relation to nonuniformities in the system. This paper concentrates on combining junctions of circular pipes in an idealized form of two configurations (Junction with lateral inflow under 45°- and 90°-angle), and the uncertainties in discharge calculation, resulting from asymmetry in the velocity distribution downstream of the inflow. The interest is focused on the question: how strong does the distance of the measuring sensor from the disturbance influence the calculation of the discharge out of the velocity distribution by means of a measuring model (procedure for deduction of discharge from velocities)? The investigation is done completely numerically with 3D flow simulations. The simulations were performed with FLUENT, a commercial software-package for computational fluid dynamics (CFD). The results of the study show that the usual recommendations in practice for the distance between measuring sections and lateral inflows, for the examined hydraulic boundary conditions, lead to significantly increased uncertainties of deducted discharges. From the applied methods the one with a measuring path (velocity profile) was the most robust. The other examined methods with single -point characteristic-measuring may also give good results, but only after expert calibration of the measuring model.