An extended COPRAS method for multiattribute group decision making based on dual hesitant fuzzy Maclaurin symmetric mean

The well-known Maclaurin symmetric mean (MSM) and the dual MSM (DMSM) are introduced as important operators to handle multiattribute group decision making (MAGDM) information. The MSM and the DMSM operators have the prominent characteristic of accurately describing the interdependence of multi-input arguments. Due to their advantage, we extend the MSM and the DMSM into the dual hesitant fuzzy environment to aggregate uncertain information. Particularly, we propose some novel aggregation operators, namely dual hesitant fuzzy MSM, weighted dual hesitant fuzzy MSM, dual hesitant fuzzy dual MSM, and weighted dual hesitant fuzzy dual MSM operators. Moreover, we study some properties and special remarks regarding different values of the parameter. With an extension of the complex proportional assessment method, we formulate a new approach for the dual hesitant fuzzy MAGDM. Finally, we test the applicability and feasibility of our proposed method by solving a mobile payment platform selection problem in Ghana.     

Method of design and specification of web services based on quality system documentation

In this paper, we present a method for development and specification of web services based on the quality system documentation. The general assumption is that service oriented architecture is based on business services and these business services mostly correspond to exchanged documentation in a real business system. Documentation of a quality system is recognized in form of documents that describe business processes in a real business system and identify exchanged documentation with environment. Presented method uses documentation of quality system and documentation flow for web service specification. We developed the CASE tool for web service specification based on a new approach, and we compare it to other existing tools.

Results on the Robust Observer-based Position Controller for Parallel Kinematic Machines

The problem of state observation and position control by output feedback for a nonlinear three degrees-of-freedom (3-DOF) parallel kinematic machine (PKM) system is considered, based on the limited signal availability (only the moving platform displacement measurements are assumed available). Unknown velocity signals are estimated via a nonlinear robust observer that is designed for the nonlinear system with observable linear dynamics part and bounded nonlinearities and disturbances, and that guarantees global exponential stability of the observation error. A proportional-derivative (PD) controller is designed to solve the position control problem, utilizing the estimated velocity, as well as the gravitation compensation, dynamic friction and external disturbance compensation for the PKM. The closed-loop system is proven to have global asymptotical stability according to the Lyapunov analysis method and LaSalle’s invariance principle. Performance of the resulting observer and controller is illustrated in a simulation study of a 3-DOF PKM. Modifications to the nonlinear observer and control law are discussed, that assure convergence of the position error and state observation error to zero when the upper bounds on the model uncertainties/disturbances are not known a priori.     

PWM Control Techniques for Rectifier Filter Minimization

Minimization of input/output filters is an essential step towards manufacturing compact low-cost static power supplies. Three PWM control techniques that yield substantial filter size reduction for three-phase (self-commutated) rectifiers are presented and analyzed. Filters required by typical line-commutated rectifiers are used as the basis for comparison. Moreover, it is shown that in addition to filter minimization two of the proposed three control techniques improve substantially the rectifier total input power factor.     

Object-based selective materialization for efficient implementationof spatial data cubes

With a huge amount of data stored in spatial databases and the introduction of spatial components to many relational or object-relational databases, it is important to study the methods for spatial data warehousing and OLAP of spatial data. In this paper, we study methods for spatial OLAP, by integrating nonspatial OLAP methods with spatial database implementation techniques. A spatial data warehouse model, which consists of both spatial and nonspatial dimensions and measures, is proposed. Methods for the computation of spatial data cubes and analytical processing on such spatial data cubes are studied, with several strategies being proposed, including approximation and selective materialization of the spatial objects resulting from spatial OLAP operations. The focus of our study is on a method for spatial cube construction, called object-based selective materialization, which is different from cuboid-based selective materialization (proposed in previous studies of nonspatial data cube construction). Rather than using a cuboid as an atomic structure during the selective materialization, we explore granularity on a much finer level: that of a single cell of a cuboid. Several algorithms are proposed for object-based selective materialization of spatial data cubes, and a performance study has demonstrated the effectiveness of these techniques     

Persistent Fibroadipogenic Progenitor Expansion Following Transient DUX4 Expression Provokes a Profibrotic State in a Mouse Model for FSHD

FSHD is caused by loss of silencing of the DUX4 gene, but the DUX4 protein has not yet been directly detected immunohistologically in affected muscle, raising the possibility that DUX4 expression may occur at time points prior to obtaining adult biopsies for analysis, with consequent perturbations of muscle being responsible for disease progression. To test the extent to which muscle can regenerate following DUX4-mediated degeneration, we employed an animal model with reversible DUX4 expression, the iDUX4pA;HSA mouse. We find that muscle histology does recover substantially after DUX4 expression is switched off, with the extent of recovery correlating inversely with the duration of prior DUX4 expression. However, despite fairly normal muscle histology, and recovery of most cytological parameters, the fibroadipogenic progenitor compartment, which is significantly elevated during bouts of fiber-specific DUX4 expression, does not return to basal levels, even many weeks after a single burst of DUX4 expression. We find that muscle that has recovered from a DUX4 burst acquires a propensity for severe fibrosis, which can be revealed by subsequent cardiotoxin injuries. These results suggest that a past history of DUX4 expression leads to maintained pro-fibrotic alterations in the cellular physiology of muscle, with potential implications for therapeutic approaches.     

Analysis of common mode voltage-“neutral shift” inmedium voltage PWM adjustable speed drive (MV-ASD) systems

In this paper, an analysis of common mode voltage or “neutral lift” in the new emerging voltage source inverter type medium voltage adjustable speed drive (MV-ASD) systems is presented. Both cascaded multilevel (CML) inverter and 3-level NPC inverter topologies are analyzed. An equivalent circuit model to determine the common mode voltage stress is presented. Analysis and simulation results are discussed and worst case common mode voltage excursion is computed for an example 800 hp, 4160 V MV-ASD. It is shown that certain system components are excessively stressed and in the MV-ASD system these data are particularly useful in specifying system components and for proper design of the system. Possible effects of common mode voltage and its dv/dt on medium voltage motor bearings are discussed. A new multilevel PWM strategy is introduced which results in zero common-mode voltage. Simulation results are shown to illustrate the effectiveness of these schemes. Finally, experimental results from a 800 hp, 4160 V, MV-ASD system are presented     

Asymptotic Analysis of Optimal Uniform Polar Quantization

In this paper the simple and complete asymptotically analysis is given for a uniform polar quantizer with respect to mean-square error (MSE) i.e.granular distortion (D_g). We also give the conditions for optimality of the polar quantizer and all main equations for phase partitions and optimal number oflevels are presented. We derive the D_g^opt in a closed form. Thegain ofoptimal uniform polar quantization over product polar quantizations [1–3], is afforded by allowing a variable number of phasesat each magnitude level. We also obtain gain (G) in a closed form.     

Early experience with in situ chip-to-chip alignment characterization of Proximity Communication flip-chip package

Proximity Communication (PxC) facilitates the integration of VLSI chips in a package using near-field capacitive coupling between chips, eliminating the need for solder or wires for I/O at the chip-to-chip interface. PxC provides chip-to-chip interconnect with bandwidth density and energy per bit similar to on-chip I/O, enabling system on a chip performance within a package. We have built early packages to explore assembly concepts and developed test methods for verification of the PxC design space. This package started with an adhesively-bonded three-chip subassembly of two Island chips and one Bridge chip. The two outer Island chips were reflowed to an alumina ceramic substrate. In the resulting package, communication between chips was achieved using PxC from Island to Bridge and then from the Bridge to the other Island. We demonstrated the ability to detect the X, Y, and Z chip-to-chip relative location and the ability to steer PxC data to optimize signal integrity within the package. This paper describes the first demonstration of active monitoring of chip-to-chip alignment during thermal cycling, in a PxC-enabled package. Leveraging this work, future packages will better exploit PxC benefits such as free-space electrical interconnect and re-workability of multi-chip modules.