Transitions to the Knowledge Economy in Germany, Sweden and the Netherlands

The “digital revolution” that began in the late 1960s has transformed product markets and production processes in rich democracies. Observers depict the changes underway as a transition from the Fordist industrial economy to a new “knowledge economy,” characterized by rapid technological innovation and associated with a heightened premium on higher education.1 Although the challenges of this transition are broadly similar across the rich democracies, individual countries have navigated the course differently

Ressenyes

Obra ressenyada: Eugene A. NIDA, Fascinated by Languages. Amsterdam/Philadelphia: John Benjamins Publishing Company, 2003

Formation of optimal-order necklace modes in one-dimensional random photonic superlattices

We study the appearance of resonantly coupled optical modes, optical necklaces, in Anderson localized one-dimensional random superlattices through numerical calculations of the accumulated phase. The evolution of the optimal necklace order m* shows a gradual shift towards higher orders with increasing the sample size. We derive an empirical formula that predicts m* and discuss the situation when in a sample length L the number of degenerate in energy resonances exceeds the optimal one. We show how the \emph{extra} resonances are pushed out to the miniband edges of the necklace, thus reducing the order of the latter by multiples of two.Comment: 4 pages, 4 figure

Lower limb stiffness estimation during running: the effect of using kinematic constraints in muscle force optimization algorithms

The focus of this paper is on the effect of muscle force optimization algorithms on the human lower limb stiffness estimation. By using a forward dynamic neuromusculoskeletal model coupled with a muscle short-range stiffness model we computed the human joint stiffness of the lower limb during running. The joint stiffness values are calculated using two different muscle force optimization procedures, namely: Toque-based and Torque/Kinematic-based algorithm. A comparison between the processed EMG signal and the corresponding estimated muscle forces with the two optimization algorithms is provided. We found that the two stiffness estimates are strongly influenced by the adopted algorithm. We observed different magnitude and timing of both the estimated muscle forces and joint stiffness time profile with respect to each gait phase, as function of the optimization algorithm used

High speed induction motor and inverter drive for flywheel energy storage

The use of flywheels to store energy is a technology which is centuries old. The confluence of several modern technologies has resulted in flywheels becoming a viable solution for the needs of the transportation, electric utility, and aerospace industries. This paper discusses a high-speed induction motor and its associated inverter drive which were developed for the Federal Railroad Administration’s “Advanced Locomotive Propulsion System.” The design of the induction motor provided several significant challenges. A megawatt rated, 12,000 rpm motor operating at a rotor surface velocity speed of 230 m/s required a unique mechanical configuration to withstand the centrifugal forces as well as an electromagnetic design, which produced a high efficiency at 200 Hz. Extending the design practices used in smaller motors would not achieve the goals required for a megawatt size machine. Similarly, the inverter was developed using a soft switching technique in order to meet the demands of high power output in a compact package. Application requirements, electrical and mechanical features of the motor, design strategy for the inverter, and test results are all presented in this paper.Center for Electromechanic

Advanced Visualization and Interaction Techniques for Large High-Resolution Displays

Large high-resolution displays combine the images of multiple smaller display devices to form one large display area. A total resolution that can easily comprise several hundred megapixels makes them suited for the visualization of data sets that could not be perceived entirely on desktop PCs or laptops due to their size. At the same time, user collaboration benefits from an extended screen area that facilitates interaction with screen contents as well as interaction among users. This paper discusses the challenges and opportunities of large high-resolution displays and examines ways to set up display clusters both in terms of hardware and underlying software technology. Furthermore, it investigates how to effectively harness the computational power and resources of rendering clusters to visualize giga-scale data sets. Last but not least, traditional interaction metaphors and their scalability to large displays as well as the effect of new techniques on the user experience are discussed