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

Qubesat for Aerothermodynamic Research and Measurement on AblatioN

International audienceThe preliminary design of the QARMAN re-entry CubeSat developed by the von Karman Institute is presented in this paper from de-orbiting to payload choices. It represents an ideal cost-efficient platform for re-entry flight test and validation of thermal protection system (TPS) materials with a demonstration flight scheduled for June 2015. The CubeSat comprises a standard double-unit platform with sensors for atmospheric research and a functional unit for essential satellite operations. A third unit accommodating an ablative heat shield is added to protect the vehicle against the extreme aerothermal conditions of the re-entry. The challenging aspect of the project lies on the constraining mass and form factor from the CubeSat standard, 3kg and 34x10x10 cm 3. Finally, the preliminary design of the vehicle results in a payload of 400 g collecting data all along the re-entry trajectory including the maximal heat flux conditions

The Impact of Human Assurance on Satellite Operations

Mission assurance is a method to guarantee mission success against a known set of risks; mission assurance is generally represented as a probability against a threshold of acceptable performance. Human assurance can be considered as the likelihood of acceptable operator performance given a set of conditions that include the operator, the system, and the environment. Standard mission assurance models tend to assume a qualified crew, but do not include other aspects of the internal or external environment that may impact the reliability of the human operator. A human assurance model can be created that allows the exploration of the variability in operator performance due to the likelihood of different risks. An example human assurance model has been created for the detection of adverse trending satellite data and the need to modify the existing mission schedule to address the satellite emergency. The model leverages the Human Viewpoint framework to capture the human-focused data within the mission context. From this data, sources of risk can be identified for the socio-technical system and a risk framework developed. The resulting risk model allows exploration of the characteristics of both the operator and the operating environment, as well as the impact of organizational mitigations, on the likelihood that the socio-technical system will meet mission assurance thresholds. The method provided can be used to identify the limitations of human system performance against the established criteria

Retention of nutrients, suspended particulate matter and phytoplankton in a pondage associated with a run-of-the-river type hydroelectric power plant

Reservoirs associated with run-of-the-river type hydroelectrical power plants (i.e. pondages) have short water residence times. For this reason, pondages are thought to have a limited impact on the fluxes of particles and solutes transported by rivers. The Malause reservoir (South West France) is such a pondage. Fed by both the Garonne and Tarn rivers, it has a water residence time of only a few days. Incoming and outgoing fluxes of nutrients, suspended particulate matter (SPM) and phytoplankton were measured weekly over the course of 1 year. Mass balance calculations showed that Malause pondage retained 24% of soluble reactive phosphorus (SRP) supplied by both rivers on an annual basis. SRP retention occurred mostly in spring–summer,pointing to biological uptake. In addition, the pondage was a sink for SPM and phytoplankton, retaining 39% of SPM and 14% of chlorophyll a supplied by both rivers on an annual basis. The retention efficiency appeared to be constrained by water temperature and residence time. The pondage was a source of phytoplankton during summer, when temperature and water residence time was high. The pondage was a sink for SPM when water residence time was low (<1 day). Our observations highlight the need to reconsider the impact of minor hydrological discontinuities on the functioning of the river continuum. The shallow depth of the pondage and the presence of dense stands of submerged macrophytes have probably favoured the retention of nutrients and the sedimentation of particles within the pondage

ATLANTIC BIRDS: a data set of bird species from the Brazilian Atlantic Forest

South America holds 30% of the world's avifauna, with the Atlantic Forest representing one of the richest regions of the Neotropics. Here we have compiled a data set on Brazilian Atlantic Forest bird occurrence (150,423) and abundance samples (N = 832 bird species; 33,119 bird individuals) using multiple methods, including qualitative surveys, mist nets, point counts, and line transects). We used four main sources of data: museum collections, on-line databases, literature sources, and unpublished reports. The data set comprises 4,122 localities and data from 1815 to 2017. Most studies were conducted in the Florestas de Interior (1,510 localities) and Serra do Mar (1,280 localities) biogeographic sub-regions. Considering the three main quantitative methods (mist net, point count, and line transect), we compiled abundance data for 745 species in 576 communities. In the data set, the most frequent species were Basileuterus culicivorus, Cyclaris gujanensis, and Conophaga lineata. There were 71 singletons, such as Lipaugus conditus and Calyptura cristata. We suggest that this small number of records reinforces the critical situation of these taxa in the Atlantic Forest. The information provided in this data set can be used for macroecological studies and to foster conservation strategies in this biodiversity hotspot. No copyright restrictions are associated with the data set. Please cite this Data Paper if data are used in publications and teaching events. © 2017 by the Ecological Society of Americ