Visualizing network traffic to understand the performance of massively parallel simulations

pre-printThe performance of massively parallel applications is often heavily impacted by the cost of communication among compute nodes. However, determining how to best use the network is a formidable task, made challenging by the ever increasing size and complexity of modern supercomputers. This paper applies visualization techniques to aid parallel application developers in understanding the network activity by enabling a detailed exploration of the flow of packets through the hardware interconnect. In order to visualize this large and complex data, we employ two linked views of the hardware network. The first is a 2D view, that represents the network structure as one of several simplified planar projections. This view is designed to allow a user to easily identify trends and patterns in the network traffic. The second is a 3D view that augments the 2D view by preserving the physical network topology and providing a context that is familiar to the application developers. Using the massively parallel multi-physics code pF3D as a case study, we demonstrate that our tool provides valuable insight that we use to explain and optimize pF3D's performance on an IBM Blue Gene/P system

Proceedings of the Workshop on Challenges, Opportunities and Constraints faced by Women in Agriculture and Allied Industries

Proceedings of the Workshop on Challenges, Opportunities and Constraints faced by Women in Agriculture and Allied Industrie

Length-weight relationship and condition factor of Dawkinsia filamentosa (Valenciennes, 1844) in different aquatic habitats

The growth rate of a species in any aquatic environment is an indicator of the water quality of the system. In the current study, the Length-weight relationship (LWR) and the condition factor of Dawkinsia filamentosa from various aquatic ecosystems especially lotic, lentic and brackish lentic systems were compared. It was observed that growth rate of the fish was more in brackish lentic systems. The study showed that already reported growth rate (b) of the species in brackish lentic systems is around 3.273 indicating proximity towards the isometric growth pattern as compared to the growth rate in reservoirs (2.3184) and that in lentic systems (3.116) obtained from present study. Similar studies supplemented with environmental variables can be used to study the health status of the ecosystem. The best system suitable for the adaptive growth of the species can be ascertained only after a holistic approach involving environmental variables

A coherent feed-forward loop drives vascular regeneration in damaged aerial organs of plants growing in a normal developmental context

Aerial organs of plants, being highly prone to local injuries, require tissue restoration to ensure their survival. However, knowledge of the underlying mechanism is sparse. In this study, we mimicked natural injuries in growing leaves and stems to study the reunion between mechanically disconnected tissues. We show that PLETHORA (PLT) and AINTEGUMENTA (ANT) genes, which encode stem cell-promoting factors, are activated and contribute to vascular regeneration in response to these injuries. PLT proteins bind to and activate the CUC2 promoter. PLT proteins and CUC2 regulate the transcription of the local auxin biosynthesis gene YUC4 in a coherent feed-forward loop, and this process is necessary to drive vascular regeneration. In the absence of this PLT-mediated regeneration response, leaf ground tissue cells can neither acquire the early vascular identity marker ATHB8, nor properly polarise auxin transporters to specify new venation paths. The PLT-CUC2 module is required for vascular regeneration, but is dispensable for midvein formation in leaves. We reveal the mechanisms of vascular regeneration in plants and distinguish between the wound-repair ability of the tissue and its formation during normal development.Peer reviewe

Doctor of Philosophy in Computing

thesisThe ever-increasing amounts of data generated by scientific simulations, coupled with system I/O constraints, are fueling a need for in-situ analysis techniques, i.e., performing the analysis concurrently with the simulation. Of particular interest are approaches that produce reduced data representations while maintaining the ability to redefine, extract, and study features in a postprocess to obtain scientific insights. One such approach is using topological constructs called segmented merge trees, which record changes in the topology of super-level sets of a scalar function. They encapsulate a wide range of threshold-based features, which can be extracted for analysis and visualization; however, current techniques for their computation are not scalable enough for in-situ analysis. This thesis presents a novel distributed algorithm that, for the first time, allows large-scale, in-situ computation of segmented merge trees. Existing merge tree computation techniques are restricted to simplicial complexes and three-dimensional (3D) rectilinear grids; instead, we present the theoretical foundations for computing merge trees on CW-complexes, which represent a broader class of meshes. Based on this theoretical foundation, we present two variants of in-situ feature extraction techniques using segmented merge trees. The first approach is a fast, low communication cost technique that generates an exact solution but has limited scalability. The second is a scalable, local approximation that, nevertheless, is guaranteed to correctly extract all features up to a predefined size. We demonstrate both variants using some of the largest combustion simulations available on leadership class supercomputers. Our approach allows feature-based analysis to be performed in-situ at significantly higher frequency than currently possible and with negligible impact on the overall simulation runtime. We provide a detailed performance and scalability analysis of this technique. Furthermore, as scientific applications target exascale, challenges related to power and energy are becoming dominating concerns. To this end, this thesis explores the various performance versus power trade-offs of the presented in-situ technique, studies its behavior when various in-situ computation strategies are employed, and extrapolates the power behavior to peta-scale systems to investigate different design choices through projections

EFFICIENCY IMPROVEMENT OF SINGLE CYLINDER DIESEL ENGINE BY THE USE OF DIESEL BLENDS

The world is being modernized and industrialized day by day. As a result vehicles and engines are increasing. But energy sources used in these engines are limited and decreasing gradually. The rapidly depleting conventional petroleum resources have promoted research for alternative fuels for diesel engines. Bio-fuel, a promising substitute as an alternative fuel has got significant attention due to the limited sources of conventional fuels and environmental concern. From different possible options, fuels derived from vegetable oil present promising renewable substitutes for fossil fuels. The utilization of Straight vegetable oil fuel in diesel engine fuel has main the advantage of eliminating the energy, cost and time consumed in biodiesel production. Oil derived from soyabean plant has been considered as a sustainable alternate fuel for diesel engine. The use of straight vegetable oil encounters problem due to its high viscosity, poor volatility and cold flow

International Journal of Chemical and Physical Sciences Partial Molar Volumes of Glucose in Aqueous and Various Alcohol Medium at Different Temperatures Partial Molar Volumes of Glucose in Aqueous and Various Alcohol Medium at Different Temperatures

Abstract The study o