A Pure Java Parallel Flow Solver

In this paper an overview is given on the "Have Java" project to attain a pure Java parallel Navier-Stokes flow solver (JParNSS) based on the thread concept and remote method invocation (RMI). The goal of this project is to produce an industrial flow solver running on an arbitrary sequential or parallel architecture, utilizing the Internet, capable of handling the most complex 3D geometries as well as flow physics, and also linking to codes in other areas such as aeroelasticity etc. Since Java is completely object-oriented the code has been written in an object-oriented programming (OOP) style. The code also includes a graphics user interface (GUI) as well as an interactive steering package for the parallel architecture. The Java OOP approach provides profoundly improved software productivity, robustness, and security as well as reusability and maintainability. OOP allows code construction similar to the aerodynamic design process because objects can be software coded and integrated, reflecting actual design procedures. In addition, Java is the programming language of the Internet and thus Java is the programming language of the Internet and thus Java objects on disparate machines or even separate networks can be connected. We explain the motivation for the design of JParNSS along with its capabilities that set it apart from other solvers. In the first two sections we present a discussion of the Java language as the programming tool for aerospace applications. In section three the objectives of the Have Java project are presented. In the next section the layer structures of JParNSS are discussed with emphasis on the parallelization and client-server (RMI) layers. JParNSS, like its predecessor ParNSS (ANSI-C), is based on the multiblock idea, and allows for arbitrarily complex topologies. Grids are accepted in GridPro property settings, grids of any size or block number can be directly read by JParNSS without any further modifications, requiring no additional preparation time for the solver input. In the last section, computational results are presented, with emphasis on multiprocessor Pentium and Sun parallel systems run by the Solaris operating system (OS)

A Test Suite for High-Performance Parallel Java

The Java programming language has a number of features that make it attractive for writing high-quality, portable parallel programs. A pure object formulation, strong typing and the exception model make programs easier to create, debug, and maintain. The elegant threading provides a simple route to parallelism on shared-memory machines. Anticipating great improvements in numerical performance, this paper presents a suite of simple programs that indicate how a pure Java Navier-Stokes solver might perform. The suite includes a parallel Euler solver. We present results from a 32-processor Hewlett-Packard machine and a 4-processor Sun server. While speedup is excellent on both machines, indicating a high-quality thread scheduler, the single-processor performance needs much improvement

eServices in Retail - An Extended Service Blueprinting Approach

Offering business services is widely considered as a means for superior value creation, and increasing research activities in the emerging disciplines of Service Sciences and Service Science Management and Engineering (SSME) can be ascertained. Even so, service research often focuses on analysing the customer interface of service processes while neglecting the back stage of service delivery. Moreover, services in retail with their distinctive characteristics are also seldom addressed. We propose an adapted service blueprinting approach which we designed to support the digitalization of business services in retail. After comparing traditional service blueprinting approaches we reconstruct a meta model to conceptualize the rather non-formalized service blueprinting approach as a modeling language. Consecutively, we extend the meta model for displaying the degree of digitalization in service systems, comprising physical goods suppliers, retailers and customers as stakeholders. By applying the extended blueprinting approach, we propose IT artifacts to facilitate coupon services in retail

Towards a Contingency Theory based Model of the Influence of Regulation on MIS

In modern societies and in particular since the financial crisis legal requirements and regulations get more and more attention. The massive amount of regulations also affects management information systems (MIS) with an impact on both, the system level as well as the organizational level. To consider all these regulations is a challenging task for organizations which handle regulative complexity in different ways. Until now, the influence of the degree of regulation on the organization of MIS received only little attention in IS research. This paper introduces a theoretical model and research design that enables investigating the influence of regulation on the organization and success of MIS. The presented model is based on the contingency theory

EBSD orientation analysis based on experimental Kikuchi reference patterns

Orientation determination does not necessarily require complete knowledge of the local atomic arrangement in a crystalline phase. We present a method for microstructural phase discrimination and orientation analysis of phases for which there is only limited crystallographic information available. In this method, experimental Kikuchi diffraction patterns are utilized to generate a self-consistent master reference for use in the technique of Electron Backscatter Diffraction (EBSD). The experimentally derived master data serves as an application-specific reference in EBSD pattern matching approaches. As application examples, we map the locally varying orientations in samples of icosahedral quasicrystals observed in a Ti40Zr40Ni20 alloy, and we analyse AlNiCo decagonal quasicrystals

Strategies for parallel and numerical scalability of CFD codes

In this article we discuss a strategy for speeding up the solution of the Navier—Stokes equations on highly complex solution domains such as complete aircraft, spacecraft, or turbomachinery equipment. We have used a finite-volume code for the (non-turbulent) Navier—Stokes equations as a testbed for implementation of linked numerical and parallel processing techniques. Speedup is achieved by the Tangled Web of advanced grid topology generation, adaptive coupling, and sophisticated parallel computing techniques. An optimized grid topology is used to generate an optimized grid: on the block level such a grid is unstructured whereas within a block a structured mesh is constructed, thus retaining the geometrical flexibility of the finite element method while maintaining the numerical efficiency of the finite difference technique. To achieve a steady state solution, we use grid-sequencing: proceeding from coarse to finer grids, where the scheme is explicit in time. Adaptive coupling is derived from the observation that numerical schemes have differing efficiency during the solution process. Coupling strength between grid points is increased by using an implicit scheme at the sub-block level, then at the block level, ultimately fully implicit across the whole computational domain. Other techniques include switching numerical schemes and the physics model during the solution, and dynamic deactivation of blocks. Because the computational work per block is very variable with adaptive coupling, especially for very complex flows, we have implemented parallel dynamic load-balancing to dynamically transfer blocks between processors. Several 2D and 3D examples illustrate the functioning of the Tangled Web approach on different parallel architectures