Improving scalability with loop transformations and message aggregation in parallel object-oriented frameworks for scientific computing

Application codes reliably achieve performance far less than the advertised capabilities of existing architectures, and this problem is worsening with increasingly-parallel machines. For large-scale numerical applications, stencil operations often impose the great part of the computational cost, and the primary sources of inefficiency are the costs of message passing and poor cache utilization. This paper proposes and demonstrates optimizations for stencil and stencil-like computations for both serial and parallel environments that ameliorate these sources of inefficiency. Achieving scalability, they believe, requires both algorithm design and compile-time support. The optimizations they present are automatable because the stencil-like computations are implemented at a high level of abstraction using object-oriented parallel array class libraries. These optimizations, which are beyond the capabilities of today compilers, may be performed automatically by a preprocessor such as the one they are currently developing

Towards JMS-Compliant Group Communication

Group communication provides communication primitives with various semantics and their use greatly simplifies the development of highly available services. However, despite tremendous advances in research and numerous prototypes, group communication stays confined to small niches and academic prototypes. In contrast, message-oriented middleware such as the Java Messaging Service (JMS) is widely used, and has become a de-facto standard. We believe that the lack of standard interfaces is the reason that hinders the deployment of group communication systems. Since JMS is well-established, an interesting solution is to map group communication primitives onto the JMS API. This requires to adapt the traditional specifications of group communication in order to take into account the features of JMS. The resulting group communication API, together with corresponding specifications, defines group communication primitives compatible with the JMS syntax and semantics

Um modelo de suporte de QoS para aplicações de tempo real

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológco. Programa de Pos-Graduação em Engenharia Elétrica.Este trabalho apresenta o desenvolvimento de um modelo computacional para possibilitar que a arquitetura SALE possa atender as necessidades de tempo real das empresas virtuais. O modelo foi desenvolvido com a utilização das especificações do RT-CORBA (uma extensão do padrão CORBA para tempo real) para a definição de alguns componentes de sua estrutura, assim como a utilização de especificações de QoS para capturar as necessidades do usuário. Incluído na estrutura do modelo, foi desenvolvida uma heurística para adaptação de deadlines perdidos, que é baseada na diminuição do deadline de uma tarefa por um coeficiente de ajuste a fim de aumentar a prioridade desta, fazendo desta forma, com que a freqüência de escalonamento das tarefas seja elevada. Como validação da proposta foram feitas simulações de uso do modelo em um simulador já existente, que foi adaptado para o correto uso, onde um número de tarefas periódicas eram preestabelecidas e tentavam executar respeitando seus deadlines em um servidor. Os resultados obtidos com estas simulações mostraram que a heurística de adaptação de deadline proposta no modelo, quando analisa em seu desempenho individual de atuação sobre uma tarefa específica, atinge resultados satisfatórios, visto que superou a abordagem utilizada para comparação (escalonamento EDF) com rendimentos mais expressivos

Faculty Publications and Creative Works 1997

One of the ways we recognize our faculty at the University of New Mexico is through this annual publication which highlights our faculty\u27s scholarly and creative activities and achievements and serves as a compendium of UNM faculty efforts during the 1997 calendar year. Faculty Publications and Creative Works strives to illustrate the depth and breadth of research activities performed throughout our University\u27s laboratories, studios and classrooms. We believe that the communication of individual research is a significant method of sharing concepts and thoughts and ultimately inspiring the birth of new of ideas. In support of this, UNM faculty during 1997 produced over 2,770 works, including 2,398 scholarly papers and articles, 72 books, 63 book chapters, 82 reviews, 151 creative works and 4 patents. We are proud of the accomplishments of our faculty which are in part reflected in this book, which illustrates the diversity of intellectual pursuits in support of research and education at the University of New Mexico. Nasir Ahmed Interim Associate Provost for Research and Dean of Graduate Studie

The North American Perching and Dabbling Ducks: Their Biology and Behavior

This volume, the fourth in a series of books that collectively update and expand P. A. Johnsgard’s 1975 The Waterfowl of North America, summarizes research findings on this economically and ecologically important group of waterfowl. The volume includes the mostly tropical perching duck tribe Cairinini, of which two species, the muscovy duck and the wood duck, are representatives. Both species are adapted for foraging on the water surface, mostly on plant materials, but typically perch in trees and nest in elevated tree cavities or other elevated recesses. This volume also includes the dabbling, or surface-feeding, duck tribe Anatini, a large assemblage of duck species that mainly forage on the water surface but nest on the ground, or only very rarely in elevated locations. Of this tribe, 12 species that regularly breed in North America are included, among them such familiar species as mallards, wigeons, pintails, and teal. Descriptive accounts of the distributions, populations, ecologies, social-sexual behaviors, and breeding biology of all these species are provided, together with distribution maps. Five additional Eurasian and West Indian species have been reported several times in North America; these have been included with more abbreviated accounts, but all 17 species are illustrated by drawings, photographs, or both. The text includes about 84,000 words and contains more than 1,000 references. There are also 12 distribution maps, 21 drawings, 28 photographic plates, and 58 anatomical or behavioral sketches. doi: 10.13014/K27H1GGVhttps://digitalcommons.unl.edu/zeabook/1053/thumbnail.jp

Science-based restoration monitoring of coastal habitats, Volume Two: Tools for monitoring coastal habitats

Healthy coastal habitats are not only important ecologically; they also support healthy coastal communities and improve the quality of people’s lives. Despite their many benefits and values, coastal habitats have been systematically modified, degraded, and destroyed throughout the United States and its protectorates beginning with European colonization in the 1600’s (Dahl 1990). As a result, many coastal habitats around the United States are in desperate need of restoration. The monitoring of restoration projects, the focus of this document, is necessary to ensure that restoration efforts are successful, to further the science, and to increase the efficiency of future restoration efforts

The Searsville Lake Site (California, USA) as a candidate Global Boundary Stratotype Section and Point for the Anthropocene Series

Cores from Searsville Lake within Stanford University’s Jasper Ridge Biological Preserve, California, USA, are examined to identify a potential GSSP for the Anthropocene: core JRBP2018-VC01B (944.5 cm-long) and tightly correlated JRBP2018-VC01A (852.5 cm-long). Spanning from 1900 CE ± 3 years to 2018 CE, a secure chronology resolved to the sub-annual level allows detailed exploration of the Holocene-Anthropocene transition. We identify the primary GSSP marker as first appearance of 239,240Pu (372–374 cm) in JRBP2018-VC01B and designate the GSSP depth as the distinct boundary between wet and dry season at 366 cm (6 cm above the first sample containing 239,240Pu) and corresponding to October-December 1948 CE. This is consistent with a lag of 1–2 years between ejection of 239,240Pu into the atmosphere and deposition. Auxiliary markers include: first appearance of 137Cs in 1958; late 20th-century decreases in δ15N; late 20th-century elevation in SCPs, Hg, Pb, and other heavy metals; and changes in abundance and presence of ostracod, algae, rotifer, and protozoan microfossils. Fossil pollen document anthropogenic landscape changes related to logging and agriculture. As part of a major university, the Searsville site has long been used for research and education, serves users locally to internationally, and is protected yet accessible for future studies and communication about the Anthropocene. PLAIN WORD SUMMARY: The Global Boundary Stratotype Section and Point (GSSP) for the proposed Anthropocene Series/Epoch is suggested to lie in sediments accumulated over the last ~120 years in Searsville Lake, Woodside, California, USA. The site fulfills all of the ideal criteria for defining and placing a GSSP. In addition, the Searsville site is particularly appropriate to mark the onset of the Anthropocene, because it was anthropogenic activities–the damming of a watershed–that created a geologic record that now preserves the very signals that can be used to recognize the Anthropocene worldwide