An Application-Based Performance Evaluation of NASAs Nebula Cloud Computing Platform

Science.gov (United States)

Saini, Subhash; Heistand, Steve; Jin, Haoqiang; Chang, Johnny; Hood, Robert T.; Mehrotra, Piyush; Biswas, Rupak

2012-01-01

The high performance computing (HPC) community has shown tremendous interest in exploring cloud computing as it promises high potential. In this paper, we examine the feasibility, performance, and scalability of production quality scientific and engineering applications of interest to NASA on NASA's cloud computing platform, called Nebula, hosted at Ames Research Center. This work represents the comprehensive evaluation of Nebula using NUTTCP, HPCC, NPB, I/O, and MPI function benchmarks as well as four applications representative of the NASA HPC workload. Specifically, we compare Nebula performance on some of these benchmarks and applications to that of NASA s Pleiades supercomputer, a traditional HPC system. We also investigate the impact of virtIO and jumbo frames on interconnect performance. Overall results indicate that on Nebula (i) virtIO and jumbo frames improve network bandwidth by a factor of 5x, (ii) there is a significant virtualization layer overhead of about 10% to 25%, (iii) write performance is lower by a factor of 25x, (iv) latency for short MPI messages is very high, and (v) overall performance is 15% to 48% lower than that on Pleiades for NASA HPC applications. We also comment on the usability of the cloud platform.

Development of NASA's Small Fission Power System for Science and Human Exploration

Science.gov (United States)

Gibson, Marc A.; Mason, Lee S.; Bowman, Cheryl L.; Poston, David I.; McClure, Patrick R.; Creasy, John; Robinson, Chris

2015-01-01

Exploration of our solar system has brought many exciting challenges to our nations scientific and engineering community over the past several decades. As we expand our visions to explore new, more challenging destinations, we must also expand our technology base to support these new missions. NASAs Space Technology Mission Directorate is tasked with developing these technologies for future mission infusion and continues to seek answers to many existing technology gaps. One such technology gap is related to compact power systems (1 kWe) that provide abundant power for several years where solar energy is unavailable or inadequate. Below 1 kWe, Radioisotope Power Systems have been the workhorse for NASA and will continue to be used for lower power applications similar to the successful missions of Voyager, Ulysses, New Horizons, Cassini, and Curiosity. Above 1 kWe, fission power systems become an attractive technology offering a scalable modular design of the reactor, shield, power conversion, and heat transport subsystems. Near term emphasis has been placed in the 1-10kWe range that lies outside realistic radioisotope power levels and fills a promising technology gap capable of enabling both science and human exploration missions. History has shown that development of space reactors is technically, politically, and financially challenging and requires a new approach to their design and development. A small team of NASA and DOE experts are providing a solution to these enabling FPS technologies starting with the lowest power and most cost effective reactor series named Kilopower that is scalable from approximately 1-10 kWe.

The Concept of Business Model Scalability

DEFF Research Database (Denmark)

Lund, Morten; Nielsen, Christian

2018-01-01

-term pro table business. However, the main message of this article is that while providing a good value proposition may help the rm ‘get by’, the really successful businesses of today are those able to reach the sweet-spot of business model scalability. Design/Methodology/Approach: The article is based...... on a ve-year longitudinal action research project of over 90 companies that participated in the International Center for Innovation project aimed at building 10 global network-based business models. Findings: This article introduces and discusses the term scalability from a company-level perspective......Purpose: The purpose of the article is to de ne what scalable business models are. Central to the contemporary understanding of business models is the value proposition towards the customer and the hypotheses generated about delivering value to the customer which become a good foundation for a long...

Oracle database performance and scalability a quantitative approach

CERN Document Server

Liu, Henry H

2011-01-01

A data-driven, fact-based, quantitative text on Oracle performance and scalability With database concepts and theories clearly explained in Oracle's context, readers quickly learn how to fully leverage Oracle's performance and scalability capabilities at every stage of designing and developing an Oracle-based enterprise application. The book is based on the author's more than ten years of experience working with Oracle, and is filled with dependable, tested, and proven performance optimization techniques. Oracle Database Performance and Scalability is divided into four parts that enable reader

PKI Scalability Issues

OpenAIRE

Slagell, Adam J; Bonilla, Rafael

2004-01-01

This report surveys different PKI technologies such as PKIX and SPKI and the issues of PKI that affect scalability. Much focus is spent on certificate revocation methodologies and status verification systems such as CRLs, Delta-CRLs, CRS, Certificate Revocation Trees, Windowed Certificate Revocation, OCSP, SCVP and DVCS.

On Scalability and Replicability of Smart Grid Projects—A Case Study

Directory of Open Access Journals (Sweden)

Lukas Sigrist

2016-03-01

Full Text Available This paper studies the scalability and replicability of smart grid projects. Currently, most smart grid projects are still in the R&D or demonstration phases. The full roll-out of the tested solutions requires a suitable degree of scalability and replicability to prevent project demonstrators from remaining local experimental exercises. Scalability and replicability are the preliminary requisites to perform scaling-up and replication successfully; therefore, scalability and replicability allow for or at least reduce barriers for the growth and reuse of the results of project demonstrators. The paper proposes factors that influence and condition a project’s scalability and replicability. These factors involve technical, economic, regulatory and stakeholder acceptance related aspects, and they describe requirements for scalability and replicability. In order to assess and evaluate the identified scalability and replicability factors, data has been collected from European and national smart grid projects by means of a survey, reflecting the projects’ view and results. The evaluation of the factors allows quantifying the status quo of on-going projects with respect to the scalability and replicability, i.e., they provide a feedback on to what extent projects take into account these factors and on whether the projects’ results and solutions are actually scalable and replicable.

Scalable-to-lossless transform domain distributed video coding

DEFF Research Database (Denmark)

Huang, Xin; Ukhanova, Ann; Veselov, Anton

2010-01-01

Distributed video coding (DVC) is a novel approach providing new features as low complexity encoding by mainly exploiting the source statistics at the decoder based on the availability of decoder side information. In this paper, scalable-tolossless DVC is presented based on extending a lossy Tran...... codec provides frame by frame encoding. Comparing the lossless coding efficiency, the proposed scalable-to-lossless TDWZ video codec can save up to 5%-13% bits compared to JPEG LS and H.264 Intra frame lossless coding and do so as a scalable-to-lossless coding....

An extended systematic mapping study about the scalability of i* Models

Directory of Open Access Journals (Sweden)

Paulo Lima

2016-12-01

Full Text Available i* models have been used for requirements specification in many domains, such as healthcare, telecommunication, and air traffic control. Managing the scalability and the complexity of such models is an important challenge in Requirements Engineering (RE. Scalability is also one of the most intractable issues in the design of visual notations in general: a well-known problem with visual representations is that they do not scale well. This issue has led us to investigate scalability in i* models and its variants by means of a systematic mapping study. This paper is an extended version of a previous paper on the scalability of i* including papers indicated by specialists. Moreover, we also discuss the challenges and open issues regarding scalability of i* models and its variants. A total of 126 papers were analyzed in order to understand: how the RE community perceives scalability; and which proposals have considered this topic. We found that scalability issues are indeed perceived as relevant and that further work is still required, even though many potential solutions have already been proposed. This study can be a starting point for researchers aiming to further advance the treatment of scalability in i* models.

Scalable Transactions for Web Applications in the Cloud

NARCIS (Netherlands)

Zhou, W.; Pierre, G.E.O.; Chi, C.-H.

2009-01-01

Cloud Computing platforms provide scalability and high availability properties for web applications but they sacrifice data consistency at the same time. However, many applications cannot afford any data inconsistency. We present a scalable transaction manager for NoSQL cloud database services to

Requirements for Scalable Access Control and Security Management Architectures

National Research Council Canada - National Science Library

Keromytis, Angelos D; Smith, Jonathan M

2005-01-01

Maximizing local autonomy has led to a scalable Internet. Scalability and the capacity for distributed control have unfortunately not extended well to resource access control policies and mechanisms...

Scalable cloud without dedicated storage

Science.gov (United States)

Batkovich, D. V.; Kompaniets, M. V.; Zarochentsev, A. K.

2015-05-01

We present a prototype of a scalable computing cloud. It is intended to be deployed on the basis of a cluster without the separate dedicated storage. The dedicated storage is replaced by the distributed software storage. In addition, all cluster nodes are used both as computing nodes and as storage nodes. This solution increases utilization of the cluster resources as well as improves fault tolerance and performance of the distributed storage. Another advantage of this solution is high scalability with a relatively low initial and maintenance cost. The solution is built on the basis of the open source components like OpenStack, CEPH, etc.

Enhancing Scalability of Sparse Direct Methods

International Nuclear Information System (INIS)

Li, Xiaoye S.; Demmel, James; Grigori, Laura; Gu, Ming; Xia, Jianlin; Jardin, Steve; Sovinec, Carl; Lee, Lie-Quan

2007-01-01

TOPS is providing high-performance, scalable sparse direct solvers, which have had significant impacts on the SciDAC applications, including fusion simulation (CEMM), accelerator modeling (COMPASS), as well as many other mission-critical applications in DOE and elsewhere. Our recent developments have been focusing on new techniques to overcome scalability bottleneck of direct methods, in both time and memory. These include parallelizing symbolic analysis phase and developing linear-complexity sparse factorization methods. The new techniques will make sparse direct methods more widely usable in large 3D simulations on highly-parallel petascale computers

Modular Universal Scalable Ion-trap Quantum Computer

Science.gov (United States)

2016-06-02

SECURITY CLASSIFICATION OF: The main goal of the original MUSIQC proposal was to construct and demonstrate a modular and universally- expandable ion...Distribution Unlimited UU UU UU UU 02-06-2016 1-Aug-2010 31-Jan-2016 Final Report: Modular Universal Scalable Ion-trap Quantum Computer The views...P.O. Box 12211 Research Triangle Park, NC 27709-2211 Ion trap quantum computation, scalable modular architectures REPORT DOCUMENTATION PAGE 11

Scalable and Media Aware Adaptive Video Streaming over Wireless Networks

Directory of Open Access Journals (Sweden)

Béatrice Pesquet-Popescu

2008-07-01

Full Text Available This paper proposes an advanced video streaming system based on scalable video coding in order to optimize resource utilization in wireless networks with retransmission mechanisms at radio protocol level. The key component of this system is a packet scheduling algorithm which operates on the different substreams of a main scalable video stream and which is implemented in a so-called media aware network element. The concerned type of transport channel is a dedicated channel subject to parameters (bitrate, loss rate variations on the long run. Moreover, we propose a combined scalability approach in which common temporal and SNR scalability features can be used jointly with a partitioning of the image into regions of interest. Simulation results show that our approach provides substantial quality gain compared to classical packet transmission methods and they demonstrate how ROI coding combined with SNR scalability allows to improve again the visual quality.

Design issues for numerical libraries on scalable multicore architectures

International Nuclear Information System (INIS)

Heroux, M A

2008-01-01

Future generations of scalable computers will rely on multicore nodes for a significant portion of overall system performance. At present, most applications and libraries cannot exploit multiple cores beyond running addition MPI processes per node. In this paper we discuss important multicore architecture issues, programming models, algorithms requirements and software design related to effective use of scalable multicore computers. In particular, we focus on important issues for library research and development, making recommendations for how to effectively develop libraries for future scalable computer systems

Doing One Thing Well: Leveraging Microservices for NASA Earth Science Discovery and Access Across Heterogenous Data Sources

Science.gov (United States)

Baynes, K.; Gilman, J.; Pilone, D.; Mitchell, A. E.

2015-12-01

The NASA EOSDIS (Earth Observing System Data and Information System) Common Metadata Repository (CMR) is a continuously evolving metadata system that merges all existing capabilities and metadata from EOS ClearingHOuse (ECHO) and the Global Change Master Directory (GCMD) systems. This flagship catalog has been developed with several key requirements: fast search and ingest performance ability to integrate heterogenous external inputs and outputs high availability and resiliency scalability evolvability and expandability This talk will focus on the advantages and potential challenges of tackling these requirements using a microservices architecture, which decomposes system functionality into smaller, loosely-coupled, individually-scalable elements that communicate via well-defined APIs. In addition, time will be spent examining specific elements of the CMR architecture and identifying opportunities for future integrations.

Scuba: scalable kernel-based gene prioritization.

Science.gov (United States)

Zampieri, Guido; Tran, Dinh Van; Donini, Michele; Navarin, Nicolò; Aiolli, Fabio; Sperduti, Alessandro; Valle, Giorgio

2018-01-25

The uncovering of genes linked to human diseases is a pressing challenge in molecular biology and precision medicine. This task is often hindered by the large number of candidate genes and by the heterogeneity of the available information. Computational methods for the prioritization of candidate genes can help to cope with these problems. In particular, kernel-based methods are a powerful resource for the integration of heterogeneous biological knowledge, however, their practical implementation is often precluded by their limited scalability. We propose Scuba, a scalable kernel-based method for gene prioritization. It implements a novel multiple kernel learning approach, based on a semi-supervised perspective and on the optimization of the margin distribution. Scuba is optimized to cope with strongly unbalanced settings where known disease genes are few and large scale predictions are required. Importantly, it is able to efficiently deal both with a large amount of candidate genes and with an arbitrary number of data sources. As a direct consequence of scalability, Scuba integrates also a new efficient strategy to select optimal kernel parameters for each data source. We performed cross-validation experiments and simulated a realistic usage setting, showing that Scuba outperforms a wide range of state-of-the-art methods. Scuba achieves state-of-the-art performance and has enhanced scalability compared to existing kernel-based approaches for genomic data. This method can be useful to prioritize candidate genes, particularly when their number is large or when input data is highly heterogeneous. The code is freely available at https://github.com/gzampieri/Scuba .

Building scalable apps with Redis and Node.js

CERN Document Server

Johanan, Joshua

2014-01-01

If the phrase scalability sounds alien to you, then this is an ideal book for you. You will not need much Node.js experience as each framework is demonstrated in a way that requires no previous knowledge of the framework. You will be building scalable Node.js applications in no time! Knowledge of JavaScript is required.

Scalable shared-memory multiprocessing

CERN Document Server

Lenoski, Daniel E

1995-01-01

Dr. Lenoski and Dr. Weber have experience with leading-edge research and practical issues involved in implementing large-scale parallel systems. They were key contributors to the architecture and design of the DASH multiprocessor. Currently, they are involved with commercializing scalable shared-memory technology.

Configuration Management at NASA

Science.gov (United States)

Doreswamy, Rajiv

2013-01-01

NASA programs are characterized by complexity, harsh environments and the fact that we usually have one chance to get it right. Programs last decades and need to accept new hardware and technology as it is developed. We have multiple suppliers and international partners Our challenges are many, our costs are high and our failures are highly visible. CM systems need to be scalable, adaptable to new technology and span the life cycle of the program (30+ years). Multiple Systems, Contractors and Countries added major levels of complexity to the ISS program and CM/DM and Requirements management systems center dot CM Systems need to be designed for long design life center dot Space Station Design started in 1984 center dot Assembly Complete in 2012 center dot Systems were developed on a task basis without an overall system perspective center dot Technology moves faster than a large project office, try to make sure you have a system that can adapt

A scalable healthcare information system based on a service-oriented architecture.

Science.gov (United States)

Yang, Tzu-Hsiang; Sun, Yeali S; Lai, Feipei

2011-06-01

Many existing healthcare information systems are composed of a number of heterogeneous systems and face the important issue of system scalability. This paper first describes the comprehensive healthcare information systems used in National Taiwan University Hospital (NTUH) and then presents a service-oriented architecture (SOA)-based healthcare information system (HIS) based on the service standard HL7. The proposed architecture focuses on system scalability, in terms of both hardware and software. Moreover, we describe how scalability is implemented in rightsizing, service groups, databases, and hardware scalability. Although SOA-based systems sometimes display poor performance, through a performance evaluation of our HIS based on SOA, the average response time for outpatient, inpatient, and emergency HL7Central systems are 0.035, 0.04, and 0.036 s, respectively. The outpatient, inpatient, and emergency WebUI average response times are 0.79, 1.25, and 0.82 s. The scalability of the rightsizing project and our evaluation results show that the SOA HIS we propose provides evidence that SOA can provide system scalability and sustainability in a highly demanding healthcare information system.

JPEG2000-Compatible Scalable Scheme for Wavelet-Based Video Coding

Directory of Open Access Journals (Sweden)

Thomas André

2007-03-01

Full Text Available We present a simple yet efficient scalable scheme for wavelet-based video coders, able to provide on-demand spatial, temporal, and SNR scalability, and fully compatible with the still-image coding standard JPEG2000. Whereas hybrid video coders must undergo significant changes in order to support scalability, our coder only requires a specific wavelet filter for temporal analysis, as well as an adapted bit allocation procedure based on models of rate-distortion curves. Our study shows that scalably encoded sequences have the same or almost the same quality than nonscalably encoded ones, without a significant increase in complexity. A full compatibility with Motion JPEG2000, which tends to be a serious candidate for the compression of high-definition video sequences, is ensured.

JPEG2000-Compatible Scalable Scheme for Wavelet-Based Video Coding

Directory of Open Access Journals (Sweden)

André Thomas

2007-01-01

Full Text Available We present a simple yet efficient scalable scheme for wavelet-based video coders, able to provide on-demand spatial, temporal, and SNR scalability, and fully compatible with the still-image coding standard JPEG2000. Whereas hybrid video coders must undergo significant changes in order to support scalability, our coder only requires a specific wavelet filter for temporal analysis, as well as an adapted bit allocation procedure based on models of rate-distortion curves. Our study shows that scalably encoded sequences have the same or almost the same quality than nonscalably encoded ones, without a significant increase in complexity. A full compatibility with Motion JPEG2000, which tends to be a serious candidate for the compression of high-definition video sequences, is ensured.

Declarative and Scalable Selection for Map Visualizations

DEFF Research Database (Denmark)

Kefaloukos, Pimin Konstantin Balic

and is itself a source and cause of prolific data creation. This calls for scalable map processing techniques that can handle the data volume and which play well with the predominant data models on the Web. (4) Maps are now consumed around the clock by a global audience. While historical maps were singleuser......-defined constraints as well as custom objectives. The purpose of the language is to derive a target multi-scale database from a source database according to holistic specifications. (b) The Glossy SQL compiler allows Glossy SQL to be scalably executed in a spatial analytics system, such as a spatial relational......, there are indications that the method is scalable for databases that contain millions of records, especially if the target language of the compiler is substituted by a cluster-ready variant of SQL. While several realistic use cases for maps have been implemented in CVL, additional non-geographic data visualization uses...

Scalable robotic biofabrication of tissue spheroids

International Nuclear Information System (INIS)

Mehesz, A Nagy; Hajdu, Z; Visconti, R P; Markwald, R R; Mironov, V; Brown, J; Beaver, W; Da Silva, J V L

2011-01-01

Development of methods for scalable biofabrication of uniformly sized tissue spheroids is essential for tissue spheroid-based bioprinting of large size tissue and organ constructs. The most recent scalable technique for tissue spheroid fabrication employs a micromolded recessed template prepared in a non-adhesive hydrogel, wherein the cells loaded into the template self-assemble into tissue spheroids due to gravitational force. In this study, we present an improved version of this technique. A new mold was designed to enable generation of 61 microrecessions in each well of a 96-well plate. The microrecessions were seeded with cells using an EpMotion 5070 automated pipetting machine. After 48 h of incubation, tissue spheroids formed at the bottom of each microrecession. To assess the quality of constructs generated using this technology, 600 tissue spheroids made by this method were compared with 600 spheroids generated by the conventional hanging drop method. These analyses showed that tissue spheroids fabricated by the micromolded method are more uniform in diameter. Thus, use of micromolded recessions in a non-adhesive hydrogel, combined with automated cell seeding, is a reliable method for scalable robotic fabrication of uniform-sized tissue spheroids.

Scalable robotic biofabrication of tissue spheroids

Energy Technology Data Exchange (ETDEWEB)

Mehesz, A Nagy; Hajdu, Z; Visconti, R P; Markwald, R R; Mironov, V [Advanced Tissue Biofabrication Center, Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC (United States); Brown, J [Department of Mechanical Engineering, Clemson University, Clemson, SC (United States); Beaver, W [York Technical College, Rock Hill, SC (United States); Da Silva, J V L, E-mail: mironovv@musc.edu [Renato Archer Information Technology Center-CTI, Campinas (Brazil)

2011-06-15

Development of methods for scalable biofabrication of uniformly sized tissue spheroids is essential for tissue spheroid-based bioprinting of large size tissue and organ constructs. The most recent scalable technique for tissue spheroid fabrication employs a micromolded recessed template prepared in a non-adhesive hydrogel, wherein the cells loaded into the template self-assemble into tissue spheroids due to gravitational force. In this study, we present an improved version of this technique. A new mold was designed to enable generation of 61 microrecessions in each well of a 96-well plate. The microrecessions were seeded with cells using an EpMotion 5070 automated pipetting machine. After 48 h of incubation, tissue spheroids formed at the bottom of each microrecession. To assess the quality of constructs generated using this technology, 600 tissue spheroids made by this method were compared with 600 spheroids generated by the conventional hanging drop method. These analyses showed that tissue spheroids fabricated by the micromolded method are more uniform in diameter. Thus, use of micromolded recessions in a non-adhesive hydrogel, combined with automated cell seeding, is a reliable method for scalable robotic fabrication of uniform-sized tissue spheroids.

Architectures and Applications for Scalable Quantum Information Systems

Science.gov (United States)

2007-01-01

Gershenfeld and I. Chuang. Quantum computing with molecules. Scientific American, June 1998. [16] A. Globus, D. Bailey, J. Han, R. Jaffe, C. Levit , R...AFRL-IF-RS-TR-2007-12 Final Technical Report January 2007 ARCHITECTURES AND APPLICATIONS FOR SCALABLE QUANTUM INFORMATION SYSTEMS...NUMBER 5b. GRANT NUMBER FA8750-01-2-0521 4. TITLE AND SUBTITLE ARCHITECTURES AND APPLICATIONS FOR SCALABLE QUANTUM INFORMATION SYSTEMS 5c

Extending JPEG-LS for low-complexity scalable video coding

DEFF Research Database (Denmark)

Ukhanova, Anna; Sergeev, Anton; Forchhammer, Søren

2011-01-01

JPEG-LS, the well-known international standard for lossless and near-lossless image compression, was originally designed for non-scalable applications. In this paper we propose a scalable modification of JPEG-LS and compare it with the leading image and video coding standards JPEG2000 and H.264/SVC...

Traffic and Quality Characterization of the H.264/AVC Scalable Video Coding Extension

Directory of Open Access Journals (Sweden)

Geert Van der Auwera

2008-01-01

Full Text Available The recent scalable video coding (SVC extension to the H.264/AVC video coding standard has unprecedented compression efficiency while supporting a wide range of scalability modes, including temporal, spatial, and quality (SNR scalability, as well as combined spatiotemporal SNR scalability. The traffic characteristics, especially the bit rate variabilities, of the individual layer streams critically affect their network transport. We study the SVC traffic statistics, including the bit rate distortion and bit rate variability distortion, with long CIF resolution video sequences and compare them with the corresponding MPEG-4 Part 2 traffic statistics. We consider (i temporal scalability with three temporal layers, (ii spatial scalability with a QCIF base layer and a CIF enhancement layer, as well as (iii quality scalability modes FGS and MGS. We find that the significant improvement in RD efficiency of SVC is accompanied by substantially higher traffic variabilities as compared to the equivalent MPEG-4 Part 2 streams. We find that separately analyzing the traffic of temporal-scalability only encodings gives reasonable estimates of the traffic statistics of the temporal layers embedded in combined spatiotemporal encodings and in the base layer of combined FGS-temporal encodings. Overall, we find that SVC achieves significantly higher compression ratios than MPEG-4 Part 2, but produces unprecedented levels of traffic variability, thus presenting new challenges for the network transport of scalable video.

Scalable, full-colour and controllable chromotropic plasmonic printing

OpenAIRE

Xue, Jiancai; Zhou, Zhang-Kai; Wei, Zhiqiang; Su, Rongbin; Lai, Juan; Li, Juntao; Li, Chao; Zhang, Tengwei; Wang, Xue-Hua

2015-01-01

Plasmonic colour printing has drawn wide attention as a promising candidate for the next-generation colour-printing technology. However, an efficient approach to realize full colour and scalable fabrication is still lacking, which prevents plasmonic colour printing from practical applications. Here we present a scalable and full-colour plasmonic printing approach by combining conjugate twin-phase modulation with a plasmonic broadband absorber. More importantly, our approach also demonstrates ...

Temporal scalability comparison of the H.264/SVC and distributed video codec

DEFF Research Database (Denmark)

Huang, Xin; Ukhanova, Ann; Belyaev, Evgeny

2009-01-01

The problem of the multimedia scalable video streaming is a current topic of interest. There exist many methods for scalable video coding. This paper is focused on the scalable extension of H.264/AVC (H.264/SVC) and distributed video coding (DVC). The paper presents an efficiency comparison of SV...

Scalable and near-optimal design space exploration for embedded systems

CERN Document Server

Kritikakou, Angeliki; Goutis, Costas

2014-01-01

This book describes scalable and near-optimal, processor-level design space exploration (DSE) methodologies.  The authors present design methodologies for data storage and processing in real-time, cost-sensitive data-dominated embedded systems.  Readers will be enabled to reduce time-to-market, while satisfying system requirements for performance, area, and energy consumption, thereby minimizing the overall cost of the final design.   • Describes design space exploration (DSE) methodologies for data storage and processing in embedded systems, which achieve near-optimal solutions with scalable exploration time; • Presents a set of principles and the processes which support the development of the proposed scalable and near-optimal methodologies; • Enables readers to apply scalable and near-optimal methodologies to the intra-signal in-place optimization step for both regular and irregular memory accesses.

Software performance and scalability a quantitative approach

CERN Document Server

Liu, Henry H

2009-01-01

Praise from the Reviewers:"The practicality of the subject in a real-world situation distinguishes this book from othersavailable on the market."—Professor Behrouz Far, University of Calgary"This book could replace the computer organization texts now in use that every CS and CpEstudent must take. . . . It is much needed, well written, and thoughtful."—Professor Larry Bernstein, Stevens Institute of TechnologyA distinctive, educational text onsoftware performance and scalabilityThis is the first book to take a quantitative approach to the subject of software performance and scalability

Quality Scalability Compression on Single-Loop Solution in HEVC

Directory of Open Access Journals (Sweden)

Mengmeng Zhang

2014-01-01

Full Text Available This paper proposes a quality scalable extension design for the upcoming high efficiency video coding (HEVC standard. In the proposed design, the single-loop decoder solution is extended into the proposed scalable scenario. A novel interlayer intra/interprediction is added to reduce the amount of bits representation by exploiting the correlation between coding layers. The experimental results indicate that the average Bjøntegaard delta rate decrease of 20.50% can be gained compared with the simulcast encoding. The proposed technique achieved 47.98% Bjøntegaard delta rate reduction compared with the scalable video coding extension of the H.264/AVC. Consequently, significant rate savings confirm that the proposed method achieves better performance.

SOL: A Library for Scalable Online Learning Algorithms

OpenAIRE

Wu, Yue; Hoi, Steven C. H.; Liu, Chenghao; Lu, Jing; Sahoo, Doyen; Yu, Nenghai

2016-01-01

SOL is an open-source library for scalable online learning algorithms, and is particularly suitable for learning with high-dimensional data. The library provides a family of regular and sparse online learning algorithms for large-scale binary and multi-class classification tasks with high efficiency, scalability, portability, and extensibility. SOL was implemented in C++, and provided with a collection of easy-to-use command-line tools, python wrappers and library calls for users and develope...

A scalable distributed RRT for motion planning

KAUST Repository

Jacobs, Sam Ade

2013-05-01

Rapidly-exploring Random Tree (RRT), like other sampling-based motion planning methods, has been very successful in solving motion planning problems. Even so, sampling-based planners cannot solve all problems of interest efficiently, so attention is increasingly turning to parallelizing them. However, one challenge in parallelizing RRT is the global computation and communication overhead of nearest neighbor search, a key operation in RRTs. This is a critical issue as it limits the scalability of previous algorithms. We present two parallel algorithms to address this problem. The first algorithm extends existing work by introducing a parameter that adjusts how much local computation is done before a global update. The second algorithm radially subdivides the configuration space into regions, constructs a portion of the tree in each region in parallel, and connects the subtrees,i removing cycles if they exist. By subdividing the space, we increase computation locality enabling a scalable result. We show that our approaches are scalable. We present results demonstrating almost linear scaling to hundreds of processors on a Linux cluster and a Cray XE6 machine. © 2013 IEEE.

A scalable distributed RRT for motion planning

KAUST Repository

Jacobs, Sam Ade; Stradford, Nicholas; Rodriguez, Cesar; Thomas, Shawna; Amato, Nancy M.

2013-01-01

Rapidly-exploring Random Tree (RRT), like other sampling-based motion planning methods, has been very successful in solving motion planning problems. Even so, sampling-based planners cannot solve all problems of interest efficiently, so attention is increasingly turning to parallelizing them. However, one challenge in parallelizing RRT is the global computation and communication overhead of nearest neighbor search, a key operation in RRTs. This is a critical issue as it limits the scalability of previous algorithms. We present two parallel algorithms to address this problem. The first algorithm extends existing work by introducing a parameter that adjusts how much local computation is done before a global update. The second algorithm radially subdivides the configuration space into regions, constructs a portion of the tree in each region in parallel, and connects the subtrees,i removing cycles if they exist. By subdividing the space, we increase computation locality enabling a scalable result. We show that our approaches are scalable. We present results demonstrating almost linear scaling to hundreds of processors on a Linux cluster and a Cray XE6 machine. © 2013 IEEE.

CloudTPS: Scalable Transactions for Web Applications in the Cloud

NARCIS (Netherlands)

Zhou, W.; Pierre, G.E.O.; Chi, C.-H.

2010-01-01

NoSQL Cloud data services provide scalability and high availability properties for web applications but at the same time they sacrifice data consistency. However, many applications cannot afford any data inconsistency. CloudTPS is a scalable transaction manager to allow cloud database services to

From Digital Disruption to Business Model Scalability

DEFF Research Database (Denmark)

Nielsen, Christian; Lund, Morten; Thomsen, Peter Poulsen

2017-01-01

This article discusses the terms disruption, digital disruption, business models and business model scalability. It illustrates how managers should be using these terms for the benefit of their business by developing business models capable of achieving exponentially increasing returns to scale...... will seldom lead to business model scalability capable of competing with digital disruption(s)....... as a response to digital disruption. A series of case studies illustrate that besides frequent existing messages in the business literature relating to the importance of creating agile businesses, both in growing and declining economies, as well as hard to copy value propositions or value propositions that take...

Scalable Packet Classification with Hash Tables

Science.gov (United States)

Wang, Pi-Chung

In the last decade, the technique of packet classification has been widely deployed in various network devices, including routers, firewalls and network intrusion detection systems. In this work, we improve the performance of packet classification by using multiple hash tables. The existing hash-based algorithms have superior scalability with respect to the required space; however, their search performance may not be comparable to other algorithms. To improve the search performance, we propose a tuple reordering algorithm to minimize the number of accessed hash tables with the aid of bitmaps. We also use pre-computation to ensure the accuracy of our search procedure. Performance evaluation based on both real and synthetic filter databases shows that our scheme is effective and scalable and the pre-computation cost is moderate.

A scalable method for parallelizing sampling-based motion planning algorithms

KAUST Repository

Jacobs, Sam Ade; Manavi, Kasra; Burgos, Juan; Denny, Jory; Thomas, Shawna; Amato, Nancy M.

2012-01-01

This paper describes a scalable method for parallelizing sampling-based motion planning algorithms. It subdivides configuration space (C-space) into (possibly overlapping) regions and independently, in parallel, uses standard (sequential) sampling-based planners to construct roadmaps in each region. Next, in parallel, regional roadmaps in adjacent regions are connected to form a global roadmap. By subdividing the space and restricting the locality of connection attempts, we reduce the work and inter-processor communication associated with nearest neighbor calculation, a critical bottleneck for scalability in existing parallel motion planning methods. We show that our method is general enough to handle a variety of planning schemes, including the widely used Probabilistic Roadmap (PRM) and Rapidly-exploring Random Trees (RRT) algorithms. We compare our approach to two other existing parallel algorithms and demonstrate that our approach achieves better and more scalable performance. Our approach achieves almost linear scalability on a 2400 core LINUX cluster and on a 153,216 core Cray XE6 petascale machine. © 2012 IEEE.

A scalable method for parallelizing sampling-based motion planning algorithms

KAUST Repository

Jacobs, Sam Ade

2012-05-01

This paper describes a scalable method for parallelizing sampling-based motion planning algorithms. It subdivides configuration space (C-space) into (possibly overlapping) regions and independently, in parallel, uses standard (sequential) sampling-based planners to construct roadmaps in each region. Next, in parallel, regional roadmaps in adjacent regions are connected to form a global roadmap. By subdividing the space and restricting the locality of connection attempts, we reduce the work and inter-processor communication associated with nearest neighbor calculation, a critical bottleneck for scalability in existing parallel motion planning methods. We show that our method is general enough to handle a variety of planning schemes, including the widely used Probabilistic Roadmap (PRM) and Rapidly-exploring Random Trees (RRT) algorithms. We compare our approach to two other existing parallel algorithms and demonstrate that our approach achieves better and more scalable performance. Our approach achieves almost linear scalability on a 2400 core LINUX cluster and on a 153,216 core Cray XE6 petascale machine. © 2012 IEEE.

Efficient Enhancement for Spatial Scalable Video Coding Transmission

Directory of Open Access Journals (Sweden)

Mayada Khairy

2017-01-01

Full Text Available Scalable Video Coding (SVC is an international standard technique for video compression. It is an extension of H.264 Advanced Video Coding (AVC. In the encoding of video streams by SVC, it is suitable to employ the macroblock (MB mode because it affords superior coding efficiency. However, the exhaustive mode decision technique that is usually used for SVC increases the computational complexity, resulting in a longer encoding time (ET. Many other algorithms were proposed to solve this problem with imperfection of increasing transmission time (TT across the network. To minimize the ET and TT, this paper introduces four efficient algorithms based on spatial scalability. The algorithms utilize the mode-distribution correlation between the base layer (BL and enhancement layers (ELs and interpolation between the EL frames. The proposed algorithms are of two categories. Those of the first category are based on interlayer residual SVC spatial scalability. They employ two methods, namely, interlayer interpolation (ILIP and the interlayer base mode (ILBM method, and enable ET and TT savings of up to 69.3% and 83.6%, respectively. The algorithms of the second category are based on full-search SVC spatial scalability. They utilize two methods, namely, full interpolation (FIP and the full-base mode (FBM method, and enable ET and TT savings of up to 55.3% and 76.6%, respectively.

Embedded High Performance Scalable Computing Systems

National Research Council Canada - National Science Library

Ngo, David

2003-01-01

The Embedded High Performance Scalable Computing Systems (EHPSCS) program is a cooperative agreement between Sanders, A Lockheed Martin Company and DARPA that ran for three years, from Apr 1995 - Apr 1998...

Lessons Learned while Exploring Cloud-Native Architectures for NASA EOSDIS Applications and Systems

Science.gov (United States)

Pilone, D.

2016-12-01

As new, high data rate missions begin collecting data, the NASA's Earth Observing System Data and Information System (EOSDIS) archive is projected to grow roughly 20x to over 300PBs by 2025. To prepare for the dramatic increase in data and enable broad scientific inquiry into larger time series and datasets, NASA has been exploring the impact of applying cloud technologies throughout EOSDIS. In this talk we will provide an overview of NASA's prototyping and lessons learned in applying cloud architectures to: Highly scalable and extensible ingest and archive of EOSDIS data Going "all-in" on cloud based application architectures including "serverless" data processing pipelines and evaluating approaches to vendor-lock in Rethinking data distribution and approaches to analysis in a cloud environment Incorporating and enforcing security controls while minimizing the barrier for research efforts to deploy to NASA compliant, operational environments. NASA's Earth Observing System (EOS) is a coordinated series of satellites for long term global observations. NASA's Earth Observing System Data and Information System (EOSDIS) is a multi-petabyte-scale archive of environmental data that supports global climate change research by providing end-to-end services from EOS instrument data collection to science data processing to full access to EOS and other earth science data. On a daily basis, the EOSDIS ingests, processes, archives and distributes over 3 terabytes of data from NASA's Earth Science missions representing over 6000 data products ranging from various types of science disciplines. EOSDIS has continually evolved to improve the discoverability, accessibility, and usability of high-impact NASA data spanning the multi-petabyte-scale archive of Earth science data products.

Investigation on Reliability and Scalability of an FBG-Based Hierarchical AOFSN

Directory of Open Access Journals (Sweden)

Li-Mei Peng

2010-03-01

Full Text Available The reliability and scalability of large-scale based optical fiber sensor networks (AOFSN are considered in this paper. The AOFSN network consists of three-level hierarchical sensor network architectures. The first two levels consist of active interrogation and remote nodes (RNs and the third level, called the sensor subnet (SSN, consists of passive Fiber Bragg Gratings (FBGs and a few switches. The switch architectures in the RN and various SSNs to improve the reliability and scalability of AOFSN are studied. Two SSNs with a regular topology are proposed to support simple routing and scalability in AOFSN: square-based sensor cells (SSC and pentagon-based sensor cells (PSC. The reliability and scalability are evaluated in terms of the available sensing coverage in the case of one or multiple link failures.

Scalable Coverage Maintenance for Dense Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Jun Lu

2007-06-01

Full Text Available Owing to numerous potential applications, wireless sensor networks have been attracting significant research effort recently. The critical challenge that wireless sensor networks often face is to sustain long-term operation on limited battery energy. Coverage maintenance schemes can effectively prolong network lifetime by selecting and employing a subset of sensors in the network to provide sufficient sensing coverage over a target region. We envision future wireless sensor networks composed of a vast number of miniaturized sensors in exceedingly high density. Therefore, the key issue of coverage maintenance for future sensor networks is the scalability to sensor deployment density. In this paper, we propose a novel coverage maintenance scheme, scalable coverage maintenance (SCOM, which is scalable to sensor deployment density in terms of communication overhead (i.e., number of transmitted and received beacons and computational complexity (i.e., time and space complexity. In addition, SCOM achieves high energy efficiency and load balancing over different sensors. We have validated our claims through both analysis and simulations.

DISP: Optimizations towards Scalable MPI Startup

Energy Technology Data Exchange (ETDEWEB)

Fu, Huansong [Florida State University, Tallahassee; Pophale, Swaroop S [ORNL; Gorentla Venkata, Manjunath [ORNL; Yu, Weikuan [Florida State University, Tallahassee

2016-01-01

Despite the popularity of MPI for high performance computing, the startup of MPI programs faces a scalability challenge as both the execution time and memory consumption increase drastically at scale. We have examined this problem using the collective modules of Cheetah and Tuned in Open MPI as representative implementations. Previous improvements for collectives have focused on algorithmic advances and hardware off-load. In this paper, we examine the startup cost of the collective module within a communicator and explore various techniques to improve its efficiency and scalability. Accordingly, we have developed a new scalable startup scheme with three internal techniques, namely Delayed Initialization, Module Sharing and Prediction-based Topology Setup (DISP). Our DISP scheme greatly benefits the collective initialization of the Cheetah module. At the same time, it helps boost the performance of non-collective initialization in the Tuned module. We evaluate the performance of our implementation on Titan supercomputer at ORNL with up to 4096 processes. The results show that our delayed initialization can speed up the startup of Tuned and Cheetah by an average of 32.0% and 29.2%, respectively, our module sharing can reduce the memory consumption of Tuned and Cheetah by up to 24.1% and 83.5%, respectively, and our prediction-based topology setup can speed up the startup of Cheetah by up to 80%.

Blind Cooperative Routing for Scalable and Energy-Efficient Internet of Things

KAUST Repository

Bader, Ahmed; Alouini, Mohamed-Slim

2016-01-01

Multihop networking is promoted in this paper for energy-efficient and highly-scalable Internet of Things (IoT). Recognizing concerns related to the scalability of classical multihop routing and medium access techniques, the use of blind cooperation

Towards a Scalable, Biomimetic, Antibacterial Coating

Science.gov (United States)

Dickson, Mary Nora

Corneal afflictions are the second leading cause of blindness worldwide. When a corneal transplant is unavailable or contraindicated, an artificial cornea device is the only chance to save sight. Bacterial or fungal biofilm build up on artificial cornea devices can lead to serious complications including the need for systemic antibiotic treatment and even explantation. As a result, much emphasis has been placed on anti-adhesion chemical coatings and antibiotic leeching coatings. These methods are not long-lasting, and microorganisms can eventually circumvent these measures. Thus, I have developed a surface topographical antimicrobial coating. Various surface structures including rough surfaces, superhydrophobic surfaces, and the natural surfaces of insects' wings and sharks' skin are promising anti-biofilm candidates, however none meet the criteria necessary for implementation on the surface of an artificial cornea device. In this thesis I: 1) developed scalable fabrication protocols for a library of biomimetic nanostructure polymer surfaces 2) assessed the potential these for poly(methyl methacrylate) nanopillars to kill or prevent formation of biofilm by E. coli bacteria and species of Pseudomonas and Staphylococcus bacteria and improved upon a proposed mechanism for the rupture of Gram-negative bacterial cell walls 3) developed a scalable, commercially viable method for producing antibacterial nanopillars on a curved, PMMA artificial cornea device and 4) developed scalable fabrication protocols for implantation of antibacterial nanopatterned surfaces on the surfaces of thermoplastic polyurethane materials, commonly used in catheter tubings. This project constitutes a first step towards fabrication of the first entirely PMMA artificial cornea device. The major finding of this work is that by precisely controlling the topography of a polymer surface at the nano-scale, we can kill adherent bacteria and prevent biofilm formation of certain pathogenic bacteria

Rate control scheme for consistent video quality in scalable video codec.

Science.gov (United States)

Seo, Chan-Won; Han, Jong-Ki; Nguyen, Truong Q

2011-08-01

Multimedia data delivered to mobile devices over wireless channels or the Internet are complicated by bandwidth fluctuation and the variety of mobile devices. Scalable video coding has been developed as an extension of H.264/AVC to solve this problem. Since scalable video codec provides various scalabilities to adapt the bitstream for the channel conditions and terminal types, scalable codec is one of the useful codecs for wired or wireless multimedia communication systems, such as IPTV and streaming services. In such scalable multimedia communication systems, video quality fluctuation degrades the visual perception significantly. It is important to efficiently use the target bits in order to maintain a consistent video quality or achieve a small distortion variation throughout the whole video sequence. The scheme proposed in this paper provides a useful function to control video quality in applications supporting scalability, whereas conventional schemes have been proposed to control video quality in the H.264 and MPEG-4 systems. The proposed algorithm decides the quantization parameter of the enhancement layer to maintain a consistent video quality throughout the entire sequence. The video quality of the enhancement layer is controlled based on a closed-form formula which utilizes the residual data and quantization error of the base layer. The simulation results show that the proposed algorithm controls the frame quality of the enhancement layer in a simple operation, where the parameter decision algorithm is applied to each frame.

Affordable Development and Demonstration of a Small NTR engine and Stage: A Preliminary NASA, DOE, and Industry Assessment

Science.gov (United States)

Borowski, S. K.; Sefcik, R. J.; Fittje, J. E.; McCurdy, D. R.; Qualls, A. L.; Schnitzler, B. G; Werner, J.; Weitzberg, A.; Joyner, C. R.

2015-01-01

In FY'11, Nuclear Thermal Propulsion (NTP) was identified as a key propulsion option under the Advanced In-Space Propulsion (AISP) component of NASA's Exploration Technology Development and Demonstration (ETDD) program A strategy was outlined by GRC and NASA HQ that included 2 key elements -"Foundational Technology Development" followed by specific "Technology Demonstration" projects. The "Technology Demonstration "element proposed ground technology demonstration (GTD) testing in the early 2020's, followed by a flight technology demonstration (FTD) mission by approx. 2025. In order to reduce development costs, the demonstration projects would focus on developing a small, low thrust (approx. 7.5 -16.5 klb(f)) engine that utilizes a "common" fuel element design scalable to the higher thrust (approx. 25 klb(f)) engines used in NASA's Mars DRA 5.0 study(NASA-SP-2009-566). Besides reducing development costs and allowing utilization of existing, flight proven engine hard-ware (e.g., hydrogen pumps and nozzles), small, lower thrust ground and flight demonstration engines can validate the technology and offer improved capability -increased payloads and decreased transit times -valued for robotic science missions identified in NASA's Decadal Study.

Progress Report 2008: A Scalable and Extensible Earth System Model for Climate Change Science

Energy Technology Data Exchange (ETDEWEB)

Drake, John B [ORNL; Worley, Patrick H [ORNL; Hoffman, Forrest M [ORNL; Jones, Phil [Los Alamos National Laboratory (LANL)

2009-01-01

This project employs multi-disciplinary teams to accelerate development of the Community Climate System Model (CCSM), based at the National Center for Atmospheric Research (NCAR). A consortium of eight Department of Energy (DOE) National Laboratories collaborate with NCAR and the NASA Global Modeling and Assimilation Office (GMAO). The laboratories are Argonne (ANL), Brookhaven (BNL) Los Alamos (LANL), Lawrence Berkeley (LBNL), Lawrence Livermore (LLNL), Oak Ridge (ORNL), Pacific Northwest (PNNL) and Sandia (SNL). The work plan focuses on scalablity for petascale computation and extensibility to a more comprehensive earth system model. Our stated goal is to support the DOE mission in climate change research by helping ... To determine the range of possible climate changes over the 21st century and beyond through simulations using a more accurate climate system model that includes the full range of human and natural climate feedbacks with increased realism and spatial resolution.

Scalable Integrated Region-Based Image Retrieval Using IRM and Statistical Clustering.

Science.gov (United States)

Wang, James Z.; Du, Yanping

Statistical clustering is critical in designing scalable image retrieval systems. This paper presents a scalable algorithm for indexing and retrieving images based on region segmentation. The method uses statistical clustering on region features and IRM (Integrated Region Matching), a measure developed to evaluate overall similarity between images…

Overview of NASA Langley's Piezoelectric Ceramic Packaging Technology and Applications

Science.gov (United States)

Bryant, Robert G.

2007-01-01

Over the past decade, NASA Langley Research Center (LaRC) has developed several actuator packaging concepts designed to enhance the performance of commercial electroactive ceramics. NASA LaRC focused on properly designed actuator and sensor packaging for the following reasons, increased durability, protect the working material from the environment, allow for proper mechanical and electrical contact, afford "ready to use" mechanisms that are scalable, and develop fabrication methodology applicable to any active material of the same physical class. It is more cost effective to enhance or tailor the performance of existing systems, through innovative packaging, than to develop, test and manufacture new materials. This approach led to the development of several solid state actuators that include THUNDER, the Macrofiber Composite or (MFC) and the Radial Field Diaphragm or (RFD). All these actuators are fabricated using standard materials and processes derived from earlier concepts. NASA s fabrication and packaging technology as yielded, piezoelectric actuators and sensors that are easy to implement, reliable, consistent in properties, and of lower cost to manufacture in quantity, than their predecessors (as evidenced by their continued commercial availability.) These piezoelectric actuators have helped foster new research and development in areas involving computational modeling, actuator specific refinements, and engineering system redesign which led to new applications for piezo-based devices that replace traditional systems currently in use.

Scalable fast multipole accelerated vortex methods

KAUST Repository

Hu, Qi; Gumerov, Nail A.; Yokota, Rio; Barba, Lorena A.; Duraiswami, Ramani

2014-01-01

-node communication and load balance efficiently, with only a small parallel construction overhead. This algorithm can scale to large-sized clusters showing both strong and weak scalability. Careful error and timing trade-off analysis are also performed for the cutoff

Scalability Dilemma and Statistic Multiplexed Computing — A Theory and Experiment

Directory of Open Access Journals (Sweden)

Justin Yuan Shi

2017-08-01

Full Text Available The For the last three decades, end-to-end computing paradigms, such as MPI (Message Passing Interface, RPC (Remote Procedure Call and RMI (Remote Method Invocation, have been the de facto paradigms for distributed and parallel programming. Despite of the successes, applications built using these paradigms suffer due to the proportionality factor of crash in the application with its size. Checkpoint/restore and backup/recovery are the only means to save otherwise lost critical information. The scalability dilemma is such a practical challenge that the probability of the data losses increases as the application scales in size. The theoretical significance of this practical challenge is that it undermines the fundamental structure of the scientific discovery process and mission critical services in production today. In 1997, the direct use of end-to-end reference model in distributed programming was recognized as a fallacy. The scalability dilemma was predicted. However, this voice was overrun by the passage of time. Today, the rapidly growing digitized data demands solving the increasingly critical scalability challenges. Computing architecture scalability, although loosely defined, is now the front and center of large-scale computing efforts. Constrained only by the economic law of diminishing returns, this paper proposes a narrow definition of a Scalable Computing Service (SCS. Three scalability tests are also proposed in order to distinguish service architecture flaws from poor application programming. Scalable data intensive service requires additional treatments. Thus, the data storage is assumed reliable in this paper. A single-sided Statistic Multiplexed Computing (SMC paradigm is proposed. A UVR (Unidirectional Virtual Ring SMC architecture is examined under SCS tests. SMC was designed to circumvent the well-known impossibility of end-to-end paradigms. It relies on the proven statistic multiplexing principle to deliver reliable service

Scalable Resolution Display Walls

KAUST Repository

Leigh, Jason; Johnson, Andrew; Renambot, Luc; Peterka, Tom; Jeong, Byungil; Sandin, Daniel J.; Talandis, Jonas; Jagodic, Ratko; Nam, Sungwon; Hur, Hyejung; Sun, Yiwen

2013-01-01

This article will describe the progress since 2000 on research and development in 2-D and 3-D scalable resolution display walls that are built from tiling individual lower resolution flat panel displays. The article will describe approaches and trends in display hardware construction, middleware architecture, and user-interaction design. The article will also highlight examples of use cases and the benefits the technology has brought to their respective disciplines. © 1963-2012 IEEE.

Evaluation of 3D printed anatomically scalable transfemoral prosthetic knee.

Science.gov (United States)

Ramakrishnan, Tyagi; Schlafly, Millicent; Reed, Kyle B

2017-07-01

This case study compares a transfemoral amputee's gait while using the existing Ossur Total Knee 2000 and our novel 3D printed anatomically scalable transfemoral prosthetic knee. The anatomically scalable transfemoral prosthetic knee is 3D printed out of a carbon-fiber and nylon composite that has a gear-mesh coupling with a hard-stop weight-actuated locking mechanism aided by a cross-linked four-bar spring mechanism. This design can be scaled using anatomical dimensions of a human femur and tibia to have a unique fit for each user. The transfemoral amputee who was tested is high functioning and walked on the Computer Assisted Rehabilitation Environment (CAREN) at a self-selected pace. The motion capture and force data that was collected showed that there were distinct differences in the gait dynamics. The data was used to perform the Combined Gait Asymmetry Metric (CGAM), where the scores revealed that the overall asymmetry of the gait on the Ossur Total Knee was more asymmetric than the anatomically scalable transfemoral prosthetic knee. The anatomically scalable transfemoral prosthetic knee had higher peak knee flexion that caused a large step time asymmetry. This made walking on the anatomically scalable transfemoral prosthetic knee more strenuous due to the compensatory movements in adapting to the different dynamics. This can be overcome by tuning the cross-linked spring mechanism to emulate the dynamics of the subject better. The subject stated that the knee would be good for daily use and has the potential to be adapted as a running knee.

Scalable optical switches for computing applications

NARCIS (Netherlands)

White, I.H.; Aw, E.T.; Williams, K.A.; Wang, Haibo; Wonfor, A.; Penty, R.V.

2009-01-01

A scalable photonic interconnection network architecture is proposed whereby a Clos network is populated with broadcast-and-select stages. This enables the efficient exploitation of an emerging class of photonic integrated switch fabric. A low distortion space switch technology based on recently

On the scalability of LISP and advanced overlaid services

OpenAIRE

Coras, Florin

2015-01-01

In just four decades the Internet has gone from a lab experiment to a worldwide, business critical infrastructure that caters to the communication needs of almost a half of the Earth's population. With these figures on its side, arguing against the Internet's scalability would seem rather unwise. However, the Internet's organic growth is far from finished and, as billions of new devices are expected to be joined in the not so distant future, scalability, or lack thereof, is commonly believed ...

Scalable Algorithms for Adaptive Statistical Designs

Directory of Open Access Journals (Sweden)

Robert Oehmke

2000-01-01

Full Text Available We present a scalable, high-performance solution to multidimensional recurrences that arise in adaptive statistical designs. Adaptive designs are an important class of learning algorithms for a stochastic environment, and we focus on the problem of optimally assigning patients to treatments in clinical trials. While adaptive designs have significant ethical and cost advantages, they are rarely utilized because of the complexity of optimizing and analyzing them. Computational challenges include massive memory requirements, few calculations per memory access, and multiply-nested loops with dynamic indices. We analyze the effects of various parallelization options, and while standard approaches do not work well, with effort an efficient, highly scalable program can be developed. This allows us to solve problems thousands of times more complex than those solved previously, which helps make adaptive designs practical. Further, our work applies to many other problems involving neighbor recurrences, such as generalized string matching.

Scalable fabrication of perovskite solar cells

Energy Technology Data Exchange (ETDEWEB)

Li, Zhen; Klein, Talysa R.; Kim, Dong Hoe; Yang, Mengjin; Berry, Joseph J.; van Hest, Maikel F. A. M.; Zhu, Kai

2018-03-27

Perovskite materials use earth-abundant elements, have low formation energies for deposition and are compatible with roll-to-roll and other high-volume manufacturing techniques. These features make perovskite solar cells (PSCs) suitable for terawatt-scale energy production with low production costs and low capital expenditure. Demonstrations of performance comparable to that of other thin-film photovoltaics (PVs) and improvements in laboratory-scale cell stability have recently made scale up of this PV technology an intense area of research focus. Here, we review recent progress and challenges in scaling up PSCs and related efforts to enable the terawatt-scale manufacturing and deployment of this PV technology. We discuss common device and module architectures, scalable deposition methods and progress in the scalable deposition of perovskite and charge-transport layers. We also provide an overview of device and module stability, module-level characterization techniques and techno-economic analyses of perovskite PV modules.

Model-Based Evaluation Of System Scalability: Bandwidth Analysis For Smartphone-Based Biosensing Applications

DEFF Research Database (Denmark)

Patou, François; Madsen, Jan; Dimaki, Maria

2016-01-01

Scalability is a design principle often valued for the engineering of complex systems. Scalability is the ability of a system to change the current value of one of its specification parameters. Although targeted frameworks are available for the evaluation of scalability for specific digital systems...... re-engineering of 5 independent system modules, from the replacement of a wireless Bluetooth interface, to the revision of the ADC sample-and-hold operation could help increase system bandwidth....

Scalability of Sustainable Business Models in Hybrid Organizations

Directory of Open Access Journals (Sweden)

Adam Jabłoński

2016-02-01

Full Text Available The dynamics of change in modern business create new mechanisms for company management to determine their pursuit and the achievement of their high performance. This performance maintained over a long period of time becomes a source of ensuring business continuity by companies. An ontological being enabling the adoption of such assumptions is such a business model that has the ability to generate results in every possible market situation and, moreover, it has the features of permanent adaptability. A feature that describes the adaptability of the business model is its scalability. Being a factor ensuring more work and more efficient work with an increasing number of components, scalability can be applied to the concept of business models as the company’s ability to maintain similar or higher performance through it. Ensuring the company’s performance in the long term helps to build the so-called sustainable business model that often balances the objectives of stakeholders and shareholders, and that is created by the implemented principles of value-based management and corporate social responsibility. This perception of business paves the way for building hybrid organizations that integrate business activities with pro-social ones. The combination of an approach typical of hybrid organizations in designing and implementing sustainable business models pursuant to the scalability criterion seems interesting from the cognitive point of view. Today, hybrid organizations are great spaces for building effective and efficient mechanisms for dialogue between business and society. This requires the appropriate business model. The purpose of the paper is to present the conceptualization and operationalization of scalability of sustainable business models that determine the performance of a hybrid organization in the network environment. The paper presents the original concept of applying scalability in sustainable business models with detailed

Fast & scalable pattern transfer via block copolymer nanolithography

DEFF Research Database (Denmark)

Li, Tao; Wang, Zhongli; Schulte, Lars

2015-01-01

A fully scalable and efficient pattern transfer process based on block copolymer (BCP) self-assembling directly on various substrates is demonstrated. PS-rich and PDMS-rich poly(styrene-b-dimethylsiloxane) (PS-b-PDMS) copolymers are used to give monolayer sphere morphology after spin-casting of s......A fully scalable and efficient pattern transfer process based on block copolymer (BCP) self-assembling directly on various substrates is demonstrated. PS-rich and PDMS-rich poly(styrene-b-dimethylsiloxane) (PS-b-PDMS) copolymers are used to give monolayer sphere morphology after spin...... on long range lateral order, including fabrication of substrates for catalysis, solar cells, sensors, ultrafiltration membranes and templating of semiconductors or metals....

Scalable Motion Estimation Processor Core for Multimedia System-on-Chip Applications

Science.gov (United States)

Lai, Yeong-Kang; Hsieh, Tian-En; Chen, Lien-Fei

2007-04-01

In this paper, we describe a high-throughput and scalable motion estimation processor architecture for multimedia system-on-chip applications. The number of processing elements (PEs) is scalable according to the variable algorithm parameters and the performance required for different applications. Using the PE rings efficiently and an intelligent memory-interleaving organization, the efficiency of the architecture can be increased. Moreover, using efficient on-chip memories and a data management technique can effectively decrease the power consumption and memory bandwidth. Techniques for reducing the number of interconnections and external memory accesses are also presented. Our results demonstrate that the proposed scalable PE-ringed architecture is a flexible and high-performance processor core in multimedia system-on-chip applications.

Accounting Fundamentals and the Variation of Stock Price: Factoring in the Investment Scalability

Directory of Open Access Journals (Sweden)

Sumiyana Sumiyana

2010-05-01

Full Text Available This study develops a new return model with respect to accounting fundamentals. The new return model is based on Chen and Zhang (2007. This study takes into account theinvestment scalability information. Specifically, this study splitsthe scale of firm’s operations into short-run and long-runinvestment scalabilities. We document that five accounting fun-damentals explain the variation of annual stock return. Thefactors, comprised book value, earnings yield, short-run andlong-run investment scalabilities, and growth opportunities, co associate positively with stock price. The remaining factor,which is the pure interest rate, is negatively related to annualstock return. This study finds that inducing short-run and long-run investment scalabilities into the model could improve the degree of association. In other words, they have value rel-evance. Finally, this study suggests that basic trading strategieswill improve if investors revert to the accounting fundamentals. Keywords: accounting fundamentals; book value; earnings yield; growth opportuni­ties; short­run and long­run investment scalabilities; trading strategy;value relevance

Scalable and balanced dynamic hybrid data assimilation

Science.gov (United States)

Kauranne, Tuomo; Amour, Idrissa; Gunia, Martin; Kallio, Kari; Lepistö, Ahti; Koponen, Sampsa

2017-04-01

Scalability of complex weather forecasting suites is dependent on the technical tools available for implementing highly parallel computational kernels, but to an equally large extent also on the dependence patterns between various components of the suite, such as observation processing, data assimilation and the forecast model. Scalability is a particular challenge for 4D variational assimilation methods that necessarily couple the forecast model into the assimilation process and subject this combination to an inherently serial quasi-Newton minimization process. Ensemble based assimilation methods are naturally more parallel, but large models force ensemble sizes to be small and that results in poor assimilation accuracy, somewhat akin to shooting with a shotgun in a million-dimensional space. The Variational Ensemble Kalman Filter (VEnKF) is an ensemble method that can attain the accuracy of 4D variational data assimilation with a small ensemble size. It achieves this by processing a Gaussian approximation of the current error covariance distribution, instead of a set of ensemble members, analogously to the Extended Kalman Filter EKF. Ensemble members are re-sampled every time a new set of observations is processed from a new approximation of that Gaussian distribution which makes VEnKF a dynamic assimilation method. After this a smoothing step is applied that turns VEnKF into a dynamic Variational Ensemble Kalman Smoother VEnKS. In this smoothing step, the same process is iterated with frequent re-sampling of the ensemble but now using past iterations as surrogate observations until the end result is a smooth and balanced model trajectory. In principle, VEnKF could suffer from similar scalability issues as 4D-Var. However, this can be avoided by isolating the forecast model completely from the minimization process by implementing the latter as a wrapper code whose only link to the model is calling for many parallel and totally independent model runs, all of them

On the scalability of uncoordinated multiple access for the Internet of Things

KAUST Repository

Chisci, Giovanni

2017-11-16

The Internet of things (IoT) will entail massive number of wireless connections with sporadic traffic patterns. To support the IoT traffic, several technologies are evolving to support low power wide area (LPWA) wireless communications. However, LPWA networks rely on variations of uncoordinated spectrum access, either for data transmissions or scheduling requests, thus imposing a scalability problem to the IoT. This paper presents a novel spatiotemporal model to study the scalability of the ALOHA medium access. In particular, the developed mathematical model relies on stochastic geometry and queueing theory to account for spatial and temporal attributes of the IoT. To this end, the scalability of the ALOHA is characterized by the percentile of IoT devices that can be served while keeping their queues stable. The results highlight the scalability problem of ALOHA and quantify the extend to which ALOHA can support in terms of number of devices, traffic requirement, and transmission rate.

Superlinearly scalable noise robustness of redundant coupled dynamical systems.

Science.gov (United States)

Kohar, Vivek; Kia, Behnam; Lindner, John F; Ditto, William L

2016-03-01

We illustrate through theory and numerical simulations that redundant coupled dynamical systems can be extremely robust against local noise in comparison to uncoupled dynamical systems evolving in the same noisy environment. Previous studies have shown that the noise robustness of redundant coupled dynamical systems is linearly scalable and deviations due to noise can be minimized by increasing the number of coupled units. Here, we demonstrate that the noise robustness can actually be scaled superlinearly if some conditions are met and very high noise robustness can be realized with very few coupled units. We discuss these conditions and show that this superlinear scalability depends on the nonlinearity of the individual dynamical units. The phenomenon is demonstrated in discrete as well as continuous dynamical systems. This superlinear scalability not only provides us an opportunity to exploit the nonlinearity of physical systems without being bogged down by noise but may also help us in understanding the functional role of coupled redundancy found in many biological systems. Moreover, engineers can exploit superlinear noise suppression by starting a coupled system near (not necessarily at) the appropriate initial condition.

Continuity-Aware Scheduling Algorithm for Scalable Video Streaming

Directory of Open Access Journals (Sweden)

Atinat Palawan

2016-05-01

Full Text Available The consumer demand for retrieving and delivering visual content through consumer electronic devices has increased rapidly in recent years. The quality of video in packet networks is susceptible to certain traffic characteristics: average bandwidth availability, loss, delay and delay variation (jitter. This paper presents a scheduling algorithm that modifies the stream of scalable video to combat jitter. The algorithm provides unequal look-ahead by safeguarding the base layer (without the need for overhead of the scalable video. The results of the experiments show that our scheduling algorithm reduces the number of frames with a violated deadline and significantly improves the continuity of the video stream without compromising the average Y Peek Signal-to-Noise Ratio (PSNR.

Scalable Partitioning Algorithms for FPGAs With Heterogeneous Resources

National Research Council Canada - National Science Library

Selvakkumaran, Navaratnasothie; Ranjan, Abhishek; Raje, Salil; Karypis, George

2004-01-01

As FPGA densities increase, partitioning-based FPGA placement approaches are becoming increasingly important as they can be used to provide high-quality and computationally scalable placement solutions...

Scalable domain decomposition solvers for stochastic PDEs in high performance computing

International Nuclear Information System (INIS)

Desai, Ajit; Pettit, Chris; Poirel, Dominique; Sarkar, Abhijit

2017-01-01

Stochastic spectral finite element models of practical engineering systems may involve solutions of linear systems or linearized systems for non-linear problems with billions of unknowns. For stochastic modeling, it is therefore essential to design robust, parallel and scalable algorithms that can efficiently utilize high-performance computing to tackle such large-scale systems. Domain decomposition based iterative solvers can handle such systems. And though these algorithms exhibit excellent scalabilities, significant algorithmic and implementational challenges exist to extend them to solve extreme-scale stochastic systems using emerging computing platforms. Intrusive polynomial chaos expansion based domain decomposition algorithms are extended here to concurrently handle high resolution in both spatial and stochastic domains using an in-house implementation. Sparse iterative solvers with efficient preconditioners are employed to solve the resulting global and subdomain level local systems through multi-level iterative solvers. We also use parallel sparse matrix–vector operations to reduce the floating-point operations and memory requirements. Numerical and parallel scalabilities of these algorithms are presented for the diffusion equation having spatially varying diffusion coefficient modeled by a non-Gaussian stochastic process. Scalability of the solvers with respect to the number of random variables is also investigated.

Scalable Video Coding with Interlayer Signal Decorrelation Techniques

Directory of Open Access Journals (Sweden)

Yang Wenxian

2007-01-01

Full Text Available Scalability is one of the essential requirements in the compression of visual data for present-day multimedia communications and storage. The basic building block for providing the spatial scalability in the scalable video coding (SVC standard is the well-known Laplacian pyramid (LP. An LP achieves the multiscale representation of the video as a base-layer signal at lower resolution together with several enhancement-layer signals at successive higher resolutions. In this paper, we propose to improve the coding performance of the enhancement layers through efficient interlayer decorrelation techniques. We first show that, with nonbiorthogonal upsampling and downsampling filters, the base layer and the enhancement layers are correlated. We investigate two structures to reduce this correlation. The first structure updates the base-layer signal by subtracting from it the low-frequency component of the enhancement layer signal. The second structure modifies the prediction in order that the low-frequency component in the new enhancement layer is diminished. The second structure is integrated in the JSVM 4.0 codec with suitable modifications in the prediction modes. Experimental results with some standard test sequences demonstrate coding gains up to 1 dB for I pictures and up to 0.7 dB for both I and P pictures.

Scalable Atomistic Simulation Algorithms for Materials Research

Directory of Open Access Journals (Sweden)

Aiichiro Nakano

2002-01-01

Full Text Available A suite of scalable atomistic simulation programs has been developed for materials research based on space-time multiresolution algorithms. Design and analysis of parallel algorithms are presented for molecular dynamics (MD simulations and quantum-mechanical (QM calculations based on the density functional theory. Performance tests have been carried out on 1,088-processor Cray T3E and 1,280-processor IBM SP3 computers. The linear-scaling algorithms have enabled 6.44-billion-atom MD and 111,000-atom QM calculations on 1,024 SP3 processors with parallel efficiency well over 90%. production-quality programs also feature wavelet-based computational-space decomposition for adaptive load balancing, spacefilling-curve-based adaptive data compression with user-defined error bound for scalable I/O, and octree-based fast visibility culling for immersive and interactive visualization of massive simulation data.

Scalable DeNoise-and-Forward in Bidirectional Relay Networks

DEFF Research Database (Denmark)

Sørensen, Jesper Hemming; Krigslund, Rasmus; Popovski, Petar

2010-01-01

In this paper a scalable relaying scheme is proposed based on an existing concept called DeNoise-and-Forward, DNF. We call it Scalable DNF, S-DNF, and it targets the scenario with multiple communication flows through a single common relay. The idea of the scheme is to combine packets at the relay...... in order to save transmissions. To ensure decodability at the end-nodes, a priori information about the content of the combined packets must be available. This is gathered during the initial transmissions to the relay. The trade-off between decodability and number of necessary transmissions is analysed...

A scalable approach to modeling groundwater flow on massively parallel computers

International Nuclear Information System (INIS)

Ashby, S.F.; Falgout, R.D.; Tompson, A.F.B.

1995-12-01

We describe a fully scalable approach to the simulation of groundwater flow on a hierarchy of computing platforms, ranging from workstations to massively parallel computers. Specifically, we advocate the use of scalable conceptual models in which the subsurface model is defined independently of the computational grid on which the simulation takes place. We also describe a scalable multigrid algorithm for computing the groundwater flow velocities. We axe thus able to leverage both the engineer's time spent developing the conceptual model and the computing resources used in the numerical simulation. We have successfully employed this approach at the LLNL site, where we have run simulations ranging in size from just a few thousand spatial zones (on workstations) to more than eight million spatial zones (on the CRAY T3D)-all using the same conceptual model

Constraint Solver Techniques for Implementing Precise and Scalable Static Program Analysis

DEFF Research Database (Denmark)

Zhang, Ye

solver using unification we could make a program analysis easier to design and implement, much more scalable, and still as precise as expected. We present an inclusion constraint language with the explicit equality constructs for specifying program analysis problems, and a parameterized framework...... developers to build reliable software systems more quickly and with fewer bugs or security defects. While designing and implementing a program analysis remains a hard work, making it both scalable and precise is even more challenging. In this dissertation, we show that with a general inclusion constraint...... data flow analyses for C language, we demonstrate a large amount of equivalences could be detected by off-line analyses, and they could then be used by a constraint solver to significantly improve the scalability of an analysis without sacrificing any precision....

Providing Data Management Support to NASA Airborne Field Studies through Streamlined Usability Design

Science.gov (United States)

Beach, A. L., III; Northup, E. A.; Early, A. B.; Chen, G.

2016-12-01

Airborne field studies are an effective way to gain a detailed understanding of atmospheric processes for scientific research on climate change and air quality relevant issues. One major function of airborne project data management is to maintain seamless data access within the science team. This allows individual instrument principal investigators (PIs) to process and validate their own data, which requires analysis of data sets from other PIs (or instruments). The project's web platform streamlines data ingest, distribution processes, and data format validation. In May 2016, the NASA Langley Research Center (LaRC) Atmospheric Science Data Center (ASDC) developed a new data management capability to help support the Korea U.S.-Air Quality (KORUS-AQ) science team. This effort is aimed at providing direct NASA Distributed Active Archive Center (DAAC) support to an airborne field study. Working closely with the science team, the ASDC developed a scalable architecture that allows investigators to easily upload and distribute their data and documentation within a secure collaborative environment. The user interface leverages modern design elements to intuitively guide the PI through each step of the data management process. In addition, the new framework creates an abstraction layer between how the data files are stored and how the data itself is organized(i.e. grouping files by PI). This approach makes it easy for PIs to simply transfer their data to one directory, while the system itself can automatically group/sort data as needed. Moreover, the platform is "server agnostic" to a certain degree, making deployment and customization more straightforward as hardware needs change. This flexible design will improve development efficiency and can be leveraged for future field campaigns. This presentation will examine the KORUS-AQ data portal as a scalable solution that applies consistent and intuitive usability design practices to support ingest and management of airborne

Algorithmic psychometrics and the scalable subject.

Science.gov (United States)

Stark, Luke

2018-04-01

Recent public controversies, ranging from the 2014 Facebook 'emotional contagion' study to psychographic data profiling by Cambridge Analytica in the 2016 American presidential election, Brexit referendum and elsewhere, signal watershed moments in which the intersecting trajectories of psychology and computer science have become matters of public concern. The entangled history of these two fields grounds the application of applied psychological techniques to digital technologies, and an investment in applying calculability to human subjectivity. Today, a quantifiable psychological subject position has been translated, via 'big data' sets and algorithmic analysis, into a model subject amenable to classification through digital media platforms. I term this position the 'scalable subject', arguing it has been shaped and made legible by algorithmic psychometrics - a broad set of affordances in digital platforms shaped by psychology and the behavioral sciences. In describing the contours of this 'scalable subject', this paper highlights the urgent need for renewed attention from STS scholars on the psy sciences, and on a computational politics attentive to psychology, emotional expression, and sociality via digital media.

Scalable Simulation of Electromagnetic Hybrid Codes

International Nuclear Information System (INIS)

Perumalla, Kalyan S.; Fujimoto, Richard; Karimabadi, Dr. Homa

2006-01-01

New discrete-event formulations of physics simulation models are emerging that can outperform models based on traditional time-stepped techniques. Detailed simulation of the Earth's magnetosphere, for example, requires execution of sub-models that are at widely differing timescales. In contrast to time-stepped simulation which requires tightly coupled updates to entire system state at regular time intervals, the new discrete event simulation (DES) approaches help evolve the states of sub-models on relatively independent timescales. However, parallel execution of DES-based models raises challenges with respect to their scalability and performance. One of the key challenges is to improve the computation granularity to offset synchronization and communication overheads within and across processors. Our previous work was limited in scalability and runtime performance due to the parallelization challenges. Here we report on optimizations we performed on DES-based plasma simulation models to improve parallel performance. The net result is the capability to simulate hybrid particle-in-cell (PIC) models with over 2 billion ion particles using 512 processors on supercomputing platforms

Scalable, full-colour and controllable chromotropic plasmonic printing

Science.gov (United States)

Xue, Jiancai; Zhou, Zhang-Kai; Wei, Zhiqiang; Su, Rongbin; Lai, Juan; Li, Juntao; Li, Chao; Zhang, Tengwei; Wang, Xue-Hua

2015-01-01

Plasmonic colour printing has drawn wide attention as a promising candidate for the next-generation colour-printing technology. However, an efficient approach to realize full colour and scalable fabrication is still lacking, which prevents plasmonic colour printing from practical applications. Here we present a scalable and full-colour plasmonic printing approach by combining conjugate twin-phase modulation with a plasmonic broadband absorber. More importantly, our approach also demonstrates controllable chromotropic capability, that is, the ability of reversible colour transformations. This chromotropic capability affords enormous potentials in building functionalized prints for anticounterfeiting, special label, and high-density data encryption storage. With such excellent performances in functional colour applications, this colour-printing approach could pave the way for plasmonic colour printing in real-world commercial utilization. PMID:26567803

Scalable Domain Decomposed Monte Carlo Particle Transport

Energy Technology Data Exchange (ETDEWEB)

O' Brien, Matthew Joseph [Univ. of California, Davis, CA (United States)

2013-12-05

In this dissertation, we present the parallel algorithms necessary to run domain decomposed Monte Carlo particle transport on large numbers of processors (millions of processors). Previous algorithms were not scalable, and the parallel overhead became more computationally costly than the numerical simulation.

The Computational Complexity, Parallel Scalability, and Performance of Atmospheric Data Assimilation Algorithms

Science.gov (United States)

Lyster, Peter M.; Guo, J.; Clune, T.; Larson, J. W.; Atlas, Robert (Technical Monitor)

2001-01-01

The computational complexity of algorithms for Four Dimensional Data Assimilation (4DDA) at NASA's Data Assimilation Office (DAO) is discussed. In 4DDA, observations are assimilated with the output of a dynamical model to generate best-estimates of the states of the system. It is thus a mapping problem, whereby scattered observations are converted into regular accurate maps of wind, temperature, moisture and other variables. The DAO is developing and using 4DDA algorithms that provide these datasets, or analyses, in support of Earth System Science research. Two large-scale algorithms are discussed. The first approach, the Goddard Earth Observing System Data Assimilation System (GEOS DAS), uses an atmospheric general circulation model (GCM) and an observation-space based analysis system, the Physical-space Statistical Analysis System (PSAS). GEOS DAS is very similar to global meteorological weather forecasting data assimilation systems, but is used at NASA for climate research. Systems of this size typically run at between 1 and 20 gigaflop/s. The second approach, the Kalman filter, uses a more consistent algorithm to determine the forecast error covariance matrix than does GEOS DAS. For atmospheric assimilation, the gridded dynamical fields typically have More than 10(exp 6) variables, therefore the full error covariance matrix may be in excess of a teraword. For the Kalman filter this problem can easily scale to petaflop/s proportions. We discuss the computational complexity of GEOS DAS and our implementation of the Kalman filter. We also discuss and quantify some of the technical issues and limitations in developing efficient, in terms of wall clock time, and scalable parallel implementations of the algorithms.

Catch the A-Train from the NASA GIBS/Worldview Platform

Science.gov (United States)

Schmaltz, J. E.; Alarcon, C.; Baynes, K.; Boller, R. A.; Cechini, M. F.; De Cesare, C.; De Luca, A. P.; Gunnoe, T.; King, B. A.; King, J.; Pressley, N. N.; Roberts, J. T.; Rodriguez, J.; Thompson, C. K.; Wong, M. M.

2016-12-01

The satellites and instruments of the Afternoon Train are providing an unprecedented combination of nearly simultaneous measurements. One of the challenges for researchers and applications users is to sift through these combinations to find particular sets of data that correspond to their interests. Using visualization of the data is one way to explore these combinations. NASA's Worldview tool is designed to do just that - to interactively browse full-resolution satellite imagery. Worldview (https://worldview.earthdata.nasa.gov/) is web-based and developed using open libraries and standards (OpenLayers, JavaScript, CSS, HTML) for cross-platform compatibility. It addresses growing user demands for access to full-resolution imagery by providing a responsive, interactive interface with global coverage and no artificial boundaries. In addition to science data imagery, Worldview provides ancillary datasets such as coastlines and borders, socio-economic layers, and satellite orbit tracks. Worldview interacts with the Earthdata Search Client to provide download of the data files associated with the imagery being viewed. The imagery used by Worldview is provided NASA's Global Imagery Browse Services (GIBS - https://earthdata.nasa.gov/gibs) which provide highly responsive, highly scalable imagery services. Requests are made via the OGC Web Map Tile Service (WMTS) standard. In addition to Worldview, other clients can be developed using a variety of web-based libraries, desktop and mobile app libraries, and GDAL script-based access. GIBS currently includes more than 106 science data sets from seven instruments aboard three of the A-Train satellites and new data sets are being added as part of the President's Big Earth Data Initiative (BEDI). Efforts are underway to include new imagery types, such as vectors and curtains, into Worldview/GIBS which will be used to visualize additional A-Train science parameters.

Using scalable vector graphics to evolve art

NARCIS (Netherlands)

den Heijer, E.; Eiben, A. E.

2016-01-01

In this paper, we describe our investigations of the use of scalable vector graphics as a genotype representation in evolutionary art. We describe the technical aspects of using SVG in evolutionary art, and explain our custom, SVG specific operators initialisation, mutation and crossover. We perform

Scalable Open Source Smart Grid Simulator (SGSim)

DEFF Research Database (Denmark)

Ebeid, Emad Samuel Malki; Jacobsen, Rune Hylsberg; Stefanni, Francesco

2017-01-01

. This paper presents an open source smart grid simulator (SGSim). The simulator is based on open source SystemC Network Simulation Library (SCNSL) and aims to model scalable smart grid applications. SGSim has been tested under different smart grid scenarios that contain hundreds of thousands of households...

Scientific visualization uncertainty, multifield, biomedical, and scalable visualization

CERN Document Server

Chen, Min; Johnson, Christopher; Kaufman, Arie; Hagen, Hans

2014-01-01

Based on the seminar that took place in Dagstuhl, Germany in June 2011, this contributed volume studies the four important topics within the scientific visualization field: uncertainty visualization, multifield visualization, biomedical visualization and scalable visualization. • Uncertainty visualization deals with uncertain data from simulations or sampled data, uncertainty due to the mathematical processes operating on the data, and uncertainty in the visual representation, • Multifield visualization addresses the need to depict multiple data at individual locations and the combination of multiple datasets, • Biomedical is a vast field with select subtopics addressed from scanning methodologies to structural applications to biological applications, • Scalability in scientific visualization is critical as data grows and computational devices range from hand-held mobile devices to exascale computational platforms. Scientific Visualization will be useful to practitioners of scientific visualization, ...

Scalable quantum memory in the ultrastrong coupling regime.

Science.gov (United States)

Kyaw, T H; Felicetti, S; Romero, G; Solano, E; Kwek, L-C

2015-03-02

Circuit quantum electrodynamics, consisting of superconducting artificial atoms coupled to on-chip resonators, represents a prime candidate to implement the scalable quantum computing architecture because of the presence of good tunability and controllability. Furthermore, recent advances have pushed the technology towards the ultrastrong coupling regime of light-matter interaction, where the qubit-resonator coupling strength reaches a considerable fraction of the resonator frequency. Here, we propose a qubit-resonator system operating in that regime, as a quantum memory device and study the storage and retrieval of quantum information in and from the Z2 parity-protected quantum memory, within experimentally feasible schemes. We are also convinced that our proposal might pave a way to realize a scalable quantum random-access memory due to its fast storage and readout performances.

Decentralized control of a scalable photovoltaic (PV)-battery hybrid power system

International Nuclear Information System (INIS)

Kim, Myungchin; Bae, Sungwoo

2017-01-01

Highlights: • This paper introduces the design and control of a PV-battery hybrid power system. • Reliable and scalable operation of hybrid power systems is achieved. • System and power control are performed without a centralized controller. • Reliability and scalability characteristics are studied in a quantitative manner. • The system control performance is verified using realistic solar irradiation data. - Abstract: This paper presents the design and control of a sustainable standalone photovoltaic (PV)-battery hybrid power system (HPS). The research aims to develop an approach that contributes to increased level of reliability and scalability for an HPS. To achieve such objectives, a PV-battery HPS with a passively connected battery was studied. A quantitative hardware reliability analysis was performed to assess the effect of energy storage configuration to the overall system reliability. Instead of requiring the feedback control information of load power through a centralized supervisory controller, the power flow in the proposed HPS is managed by a decentralized control approach that takes advantage of the system architecture. Reliable system operation of an HPS is achieved through the proposed control approach by not requiring a separate supervisory controller. Furthermore, performance degradation of energy storage can be prevented by selecting the controller gains such that the charge rate does not exceed operational requirements. The performance of the proposed system architecture with the control strategy was verified by simulation results using realistic irradiance data and a battery model in which its temperature effect was considered. With an objective to support scalable operation, details on how the proposed design could be applied were also studied so that the HPS could satisfy potential system growth requirements. Such scalability was verified by simulating various cases that involve connection and disconnection of sources and loads. The

Scalable optical quantum computer

International Nuclear Information System (INIS)

Manykin, E A; Mel'nichenko, E V

2014-01-01

A way of designing a scalable optical quantum computer based on the photon echo effect is proposed. Individual rare earth ions Pr 3+ , regularly located in the lattice of the orthosilicate (Y 2 SiO 5 ) crystal, are suggested to be used as optical qubits. Operations with qubits are performed using coherent and incoherent laser pulses. The operation protocol includes both the method of measurement-based quantum computations and the technique of optical computations. Modern hybrid photon echo protocols, which provide a sufficient quantum efficiency when reading recorded states, are considered as most promising for quantum computations and communications. (quantum computer)

SuperLU{_}DIST: A scalable distributed-memory sparse direct solver for unsymmetric linear systems

Energy Technology Data Exchange (ETDEWEB)

Li, Xiaoye S.; Demmel, James W.

2002-03-27

In this paper, we present the main algorithmic features in the software package SuperLU{_}DIST, a distributed-memory sparse direct solver for large sets of linear equations. We give in detail our parallelization strategies, with focus on scalability issues, and demonstrate the parallel performance and scalability on current machines. The solver is based on sparse Gaussian elimination, with an innovative static pivoting strategy proposed earlier by the authors. The main advantage of static pivoting over classical partial pivoting is that it permits a priori determination of data structures and communication pattern for sparse Gaussian elimination, which makes it more scalable on distributed memory machines. Based on this a priori knowledge, we designed highly parallel and scalable algorithms for both LU decomposition and triangular solve and we show that they are suitable for large-scale distributed memory machines.

Advanced technologies for scalable ATLAS conditions database access on the grid

CERN Document Server

Basset, R; Dimitrov, G; Girone, M; Hawkings, R; Nevski, P; Valassi, A; Vaniachine, A; Viegas, F; Walker, R; Wong, A

2010-01-01

During massive data reprocessing operations an ATLAS Conditions Database application must support concurrent access from numerous ATLAS data processing jobs running on the Grid. By simulating realistic work-flow, ATLAS database scalability tests provided feedback for Conditions Db software optimization and allowed precise determination of required distributed database resources. In distributed data processing one must take into account the chaotic nature of Grid computing characterized by peak loads, which can be much higher than average access rates. To validate database performance at peak loads, we tested database scalability at very high concurrent jobs rates. This has been achieved through coordinated database stress tests performed in series of ATLAS reprocessing exercises at the Tier-1 sites. The goal of database stress tests is to detect scalability limits of the hardware deployed at the Tier-1 sites, so that the server overload conditions can be safely avoided in a production environment. Our analysi...

Scalable architecture for a room temperature solid-state quantum information processor.

Science.gov (United States)

Yao, N Y; Jiang, L; Gorshkov, A V; Maurer, P C; Giedke, G; Cirac, J I; Lukin, M D

2012-04-24

The realization of a scalable quantum information processor has emerged over the past decade as one of the central challenges at the interface of fundamental science and engineering. Here we propose and analyse an architecture for a scalable, solid-state quantum information processor capable of operating at room temperature. Our approach is based on recent experimental advances involving nitrogen-vacancy colour centres in diamond. In particular, we demonstrate that the multiple challenges associated with operation at ambient temperature, individual addressing at the nanoscale, strong qubit coupling, robustness against disorder and low decoherence rates can be simultaneously achieved under realistic, experimentally relevant conditions. The architecture uses a novel approach to quantum information transfer and includes a hierarchy of control at successive length scales. Moreover, it alleviates the stringent constraints currently limiting the realization of scalable quantum processors and will provide fundamental insights into the physics of non-equilibrium many-body quantum systems.

Scalable force directed graph layout algorithms using fast multipole methods

KAUST Repository

Yunis, Enas Abdulrahman

2012-06-01

We present an extension to ExaFMM, a Fast Multipole Method library, as a generalized approach for fast and scalable execution of the Force-Directed Graph Layout algorithm. The Force-Directed Graph Layout algorithm is a physics-based approach to graph layout that treats the vertices V as repelling charged particles with the edges E connecting them acting as springs. Traditionally, the amount of work required in applying the Force-Directed Graph Layout algorithm is O(|V|2 + |E|) using direct calculations and O(|V| log |V| + |E|) using truncation, filtering, and/or multi-level techniques. Correct application of the Fast Multipole Method allows us to maintain a lower complexity of O(|V| + |E|) while regaining most of the precision lost in other techniques. Solving layout problems for truly large graphs with millions of vertices still requires a scalable algorithm and implementation. We have been able to leverage the scalability and architectural adaptability of the ExaFMM library to create a Force-Directed Graph Layout implementation that runs efficiently on distributed multicore and multi-GPU architectures. © 2012 IEEE.

Scalability of voltage-controlled filamentary and nanometallic resistance memory devices.

Science.gov (United States)

Lu, Yang; Lee, Jong Ho; Chen, I-Wei

2017-08-31

Much effort has been devoted to device and materials engineering to realize nanoscale resistance random access memory (RRAM) for practical applications, but a rational physical basis to be relied on to design scalable devices spanning many length scales is still lacking. In particular, there is no clear criterion for switching control in those RRAM devices in which resistance changes are limited to localized nanoscale filaments that experience concentrated heat, electric current and field. Here, we demonstrate voltage-controlled resistance switching, always at a constant characteristic critical voltage, for macro and nanodevices in both filamentary RRAM and nanometallic RRAM, and the latter switches uniformly and does not require a forming process. As a result, area-scalability can be achieved under a device-area-proportional current compliance for the low resistance state of the filamentary RRAM, and for both the low and high resistance states of the nanometallic RRAM. This finding will help design area-scalable RRAM at the nanoscale. It also establishes an analogy between RRAM and synapses, in which signal transmission is also voltage-controlled.

Scalability of DL_POLY on High Performance Computing Platform

Directory of Open Access Journals (Sweden)

Mabule Samuel Mabakane

2017-12-01

Full Text Available This paper presents a case study on the scalability of several versions of the molecular dynamics code (DL_POLY performed on South Africa‘s Centre for High Performance Computing e1350 IBM Linux cluster, Sun system and Lengau supercomputers. Within this study different problem sizes were designed and the same chosen systems were employed in order to test the performance of DL_POLY using weak and strong scalability. It was found that the speed-up results for the small systems were better than large systems on both Ethernet and Infiniband network. However, simulations of large systems in DL_POLY performed well using Infiniband network on Lengau cluster as compared to e1350 and Sun supercomputer.

Scalable fast multipole accelerated vortex methods

KAUST Repository

Hu, Qi

2014-05-01

The fast multipole method (FMM) is often used to accelerate the calculation of particle interactions in particle-based methods to simulate incompressible flows. To evaluate the most time-consuming kernels - the Biot-Savart equation and stretching term of the vorticity equation, we mathematically reformulated it so that only two Laplace scalar potentials are used instead of six. This automatically ensuring divergence-free far-field computation. Based on this formulation, we developed a new FMM-based vortex method on heterogeneous architectures, which distributed the work between multicore CPUs and GPUs to best utilize the hardware resources and achieve excellent scalability. The algorithm uses new data structures which can dynamically manage inter-node communication and load balance efficiently, with only a small parallel construction overhead. This algorithm can scale to large-sized clusters showing both strong and weak scalability. Careful error and timing trade-off analysis are also performed for the cutoff functions induced by the vortex particle method. Our implementation can perform one time step of the velocity+stretching calculation for one billion particles on 32 nodes in 55.9 seconds, which yields 49.12 Tflop/s.

Scalability Optimization of Seamless Positioning Service

Directory of Open Access Journals (Sweden)

Juraj Machaj

2016-01-01

Full Text Available Recently positioning services are getting more attention not only within research community but also from service providers. From the service providers point of view positioning service that will be able to work seamlessly in all environments, for example, indoor, dense urban, and rural, has a huge potential to open new markets. However, such system does not only need to provide accurate position estimates but have to be scalable and resistant to fake positioning requests. In the previous works we have proposed a modular system, which is able to provide seamless positioning in various environments. The system automatically selects optimal positioning module based on available radio signals. The system currently consists of three positioning modules—GPS, GSM based positioning, and Wi-Fi based positioning. In this paper we will propose algorithm which will reduce time needed for position estimation and thus allow higher scalability of the modular system and thus allow providing positioning services to higher amount of users. Such improvement is extremely important, for real world application where large number of users will require position estimates, since positioning error is affected by response time of the positioning server.

PM2006: a highly scalable urban planning management information system--Case study: Suzhou Urban Planning Bureau

Science.gov (United States)

Jing, Changfeng; Liang, Song; Ruan, Yong; Huang, Jie

2008-10-01

During the urbanization process, when facing complex requirements of city development, ever-growing urban data, rapid development of planning business and increasing planning complexity, a scalable, extensible urban planning management information system is needed urgently. PM2006 is such a system that can deal with these problems. In response to the status and problems in urban planning, the scalability and extensibility of PM2006 are introduced which can be seen as business-oriented workflow extensibility, scalability of DLL-based architecture, flexibility on platforms of GIS and database, scalability of data updating and maintenance and so on. It is verified that PM2006 system has good extensibility and scalability which can meet the requirements of all levels of administrative divisions and can adapt to ever-growing changes in urban planning business. At the end of this paper, the application of PM2006 in Urban Planning Bureau of Suzhou city is described.

Architecture Knowledge for Evaluating Scalable Databases

Science.gov (United States)

2015-01-16

Architecture Knowledge for Evaluating Scalable Databases 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Nurgaliev... Scala , Erlang, Javascript Cursor-based queries Supported, Not Supported JOIN queries Supported, Not Supported Complex data types Lists, maps, sets...is therefore needed, using technology such as machine learning to extract content from product documentation. The terminology used in the database

Cooperative Scalable Moving Continuous Query Processing

DEFF Research Database (Denmark)

Li, Xiaohui; Karras, Panagiotis; Jensen, Christian S.

2012-01-01

of the global view and handle the majority of the workload. Meanwhile, moving clients, having basic memory and computation resources, handle small portions of the workload. This model is further enhanced by dynamic region allocation and grid size adjustment mechanisms that reduce the communication...... and computation cost for both servers and clients. An experimental study demonstrates that our approaches offer better scalability than competitors...

On the Scalability of Time-predictable Chip-Multiprocessing

DEFF Research Database (Denmark)

Puffitsch, Wolfgang; Schoeberl, Martin

2012-01-01

Real-time systems need a time-predictable execution platform to be able to determine the worst-case execution time statically. In order to be time-predictable, several advanced processor features, such as out-of-order execution and other forms of speculation, have to be avoided. However, just using...... simple processors is not an option for embedded systems with high demands on computing power. In order to provide high performance and predictability we argue to use multiprocessor systems with a time-predictable memory interface. In this paper we present the scalability of a Java chip......-multiprocessor system that is designed to be time-predictable. Adding time-predictable caches is mandatory to achieve scalability with a shared memory multi-processor system. As Java bytecode retains information about the nature of memory accesses, it is possible to implement a memory hierarchy that takes...

ATLAS Grid Data Processing: system evolution and scalability

CERN Document Server

Golubkov, D; The ATLAS collaboration; Klimentov, A; Minaenko, A; Nevski, P; Vaniachine, A; Walker, R

2012-01-01

The production system for Grid Data Processing handles petascale ATLAS data reprocessing and Monte Carlo activities. The production system empowered further data processing steps on the Grid performed by dozens of ATLAS physics groups with coordinated access to computing resources worldwide, including additional resources sponsored by regional facilities. The system provides knowledge management of configuration parameters for massive data processing tasks, reproducibility of results, scalable database access, orchestrated workflow and performance monitoring, dynamic workload sharing, automated fault tolerance and petascale data integrity control. The system evolves to accommodate a growing number of users and new requirements from our contacts in ATLAS main areas: Trigger, Physics, Data Preparation and Software & Computing. To assure scalability, the next generation production system architecture development is in progress. We report on scaling up the production system for a growing number of users provi...

Iterative Integration of Visual Insights during Scalable Patent Search and Analysis.

Science.gov (United States)

Koch, S; Bosch, H; Giereth, M; Ertl, T

2011-05-01

Patents are of growing importance in current economic markets. Analyzing patent information has, therefore, become a common task for many interest groups. As a prerequisite for patent analysis, extensive search for relevant patent information is essential. Unfortunately, the complexity of patent material inhibits a straightforward retrieval of all relevant patent documents and leads to iterative, time-consuming approaches in practice. Already the amount of patent data to be analyzed poses challenges with respect to scalability. Further scalability issues arise concerning the diversity of users and the large variety of analysis tasks. With "PatViz", a system for interactive analysis of patent information has been developed addressing scalability at various levels. PatViz provides a visual environment allowing for interactive reintegration of insights into subsequent search iterations, thereby bridging the gap between search and analytic processes. Because of its extensibility, we expect that the approach we have taken can be employed in different problem domains that require high quality of search results regarding their completeness.

Scalable Video Streaming Relay for Smart Mobile Devices in Wireless Networks.

Science.gov (United States)

Kwon, Dongwoo; Je, Huigwang; Kim, Hyeonwoo; Ju, Hongtaek; An, Donghyeok

2016-01-01

Recently, smart mobile devices and wireless communication technologies such as WiFi, third generation (3G), and long-term evolution (LTE) have been rapidly deployed. Many smart mobile device users can access the Internet wirelessly, which has increased mobile traffic. In 2014, more than half of the mobile traffic around the world was devoted to satisfying the increased demand for the video streaming. In this paper, we propose a scalable video streaming relay scheme. Because many collisions degrade the scalability of video streaming, we first separate networks to prevent excessive contention between devices. In addition, the member device controls the video download rate in order to adapt to video playback. If the data are sufficiently buffered, the member device stops the download. If not, it requests additional video data. We implemented apps to evaluate the proposed scheme and conducted experiments with smart mobile devices. The results showed that our scheme improves the scalability of video streaming in a wireless local area network (WLAN).

Scalable Video Streaming Relay for Smart Mobile Devices in Wireless Networks

Science.gov (United States)

Kwon, Dongwoo; Je, Huigwang; Kim, Hyeonwoo; Ju, Hongtaek; An, Donghyeok

2016-01-01

Recently, smart mobile devices and wireless communication technologies such as WiFi, third generation (3G), and long-term evolution (LTE) have been rapidly deployed. Many smart mobile device users can access the Internet wirelessly, which has increased mobile traffic. In 2014, more than half of the mobile traffic around the world was devoted to satisfying the increased demand for the video streaming. In this paper, we propose a scalable video streaming relay scheme. Because many collisions degrade the scalability of video streaming, we first separate networks to prevent excessive contention between devices. In addition, the member device controls the video download rate in order to adapt to video playback. If the data are sufficiently buffered, the member device stops the download. If not, it requests additional video data. We implemented apps to evaluate the proposed scheme and conducted experiments with smart mobile devices. The results showed that our scheme improves the scalability of video streaming in a wireless local area network (WLAN). PMID:27907113

Asynchronous Checkpoint Migration with MRNet in the Scalable Checkpoint / Restart Library

Energy Technology Data Exchange (ETDEWEB)

Mohror, K; Moody, A; de Supinski, B R

2012-03-20

Applications running on today's supercomputers tolerate failures by periodically saving their state in checkpoint files on stable storage, such as a parallel file system. Although this approach is simple, the overhead of writing the checkpoints can be prohibitive, especially for large-scale jobs. In this paper, we present initial results of an enhancement to our Scalable Checkpoint/Restart Library (SCR). We employ MRNet, a tree-based overlay network library, to transfer checkpoints from the compute nodes to the parallel file system asynchronously. This enhancement increases application efficiency by removing the need for an application to block while checkpoints are transferred to the parallel file system. We show that the integration of SCR with MRNet can reduce the time spent in I/O operations by as much as 15x. However, our experiments exposed new scalability issues with our initial implementation. We discuss the sources of the scalability problems and our plans to address them.

Applications of the scalable coherent interface to data acquisition at LHC

CERN Document Server

Bogaerts, A; Divià, R; Müller, H; Parkman, C; Ponting, P J; Skaali, B; Midttun, G; Wormald, D; Wikne, J; Falciano, S; Cesaroni, F; Vinogradov, V I; Kristiansen, E H; Solberg, B; Guglielmi, A M; Worm, F H; Bovier, J; Davis, C; CERN. Geneva. Detector Research and Development Committee

1991-01-01

We propose to use the Scalable Coherent Interface (SCI) as a very high speed interconnect between LHC detector data buffers and farms of commercial trigger processors. Both the global second and third level trigger can be based on SCI as a reconfigurable and scalable system. SCI is a proposed IEEE standard which uses fast point-to-point links to provide computer-bus like services. It can connect a maximum of 65 536 nodes (memories or processors), providing data transfer rates of up to 1 Gbyte/s. Scalable data acquisition systems can be built using either simple SCI rings or complex switches. The interconnections may be flat cables, coaxial cables, or optical fibres. SCI protocols have been entirely implemented in VLSI, resulting in a significant simplification of data acquisition software. Novel SCI features allow efficient implementation of both data and processor driven readout architectures. In particular, a very efficient implementation of the third level trigger can be achieved by combining SCI's shared ...

Study on scalable Coulombic degradation for estimating the lifetime of organic light-emitting devices

International Nuclear Information System (INIS)

Zhang Wenwen; Hou Xun; Wu Zhaoxin; Liang Shixiong; Jiao Bo; Zhang Xinwen; Wang Dawei; Chen Zhijian; Gong Qihuang

2011-01-01

The luminance decays of organic light-emitting diodes (OLEDs) are investigated with initial luminance of 1000 to 20 000 cd m -2 through a scalable Coulombic degradation and a stretched exponential decay. We found that the estimated lifetime by scalable Coulombic degradation deviates from the experimental results when the OLEDs work with high initial luminance. By measuring the temperature of the device during degradation, we found that the higher device temperatures will lead to instabilities of organic materials in devices, which is expected to result in the difference between the experimental results and estimation using the scalable Coulombic degradation.

The 20-20-20 Airships NASA Centennial Challenge

Science.gov (United States)

Kiessling, Alina; Diaz, Ernesto; Rhodes, Jason; Ortega, Sam; Eberly, Eric

2015-08-01

A 2013 Keck Institute for Space Studies (KISS) study examined airships as a possible platform for Earth and space science. Airships, lighter than air, powered, maneuverable vehicles, could offer significant gains in observing time, sky and ground coverage, data downlink capability, and continuity of observations over existing suborbital options at competitive prices. The KISS study recommended three courses of action to spur the development and use of airships as a science platform. One of those recommendations was that a prize competition be developed to demonstrate a stratospheric airship. Consequently, we have been developing a NASA Centennial Challenge; (www.nasa.gov/challenges) to spur innovation in stratospheric airships as a science platform. We anticipate a multi-million dollar class prize for the first organization to fly a powered airship that remains stationary at 20km (65,000 ft) altitude for over 20 hours with a 20kg payload. The design must be scalable to longer flights with more massive payloads. A second prize tier, for a 20km flight lasting 200 hours with a 200kg payload would incentivize a further step toward a scientifically compelling and viable new platform. This technology would also have broad commercial applications including communications, asset tracking, and surveillance. Via the 20-20-20 Centennial Challenge, we are seeking to spur private industry (or non-profit institutions, including Universities) to demonstrate the capability for sustained airship flights as astronomy and Earth science platforms.

Scalable power selection method for wireless mesh networks

CSIR Research Space (South Africa)

Olwal, TO

2009-01-01

Full Text Available This paper addresses the problem of a scalable dynamic power control (SDPC) for wireless mesh networks (WMNs) based on IEEE 802.11 standards. An SDPC model that accounts for architectural complexities witnessed in multiple radios and hops...

Scalable storage for a DBMS using transparent distribution

NARCIS (Netherlands)

J.S. Karlsson; M.L. Kersten (Martin)

1997-01-01

textabstractScalable Distributed Data Structures (SDDSs) provide a self-managing and self-organizing data storage of potentially unbounded size. This stands in contrast to common distribution schemas deployed in conventional distributed DBMS. SDDSs, however, have mostly been used in synthetic

Scalable multifunction RF system concepts for joint operations

NARCIS (Netherlands)

Otten, M.P.G.; Wit, J.J.M. de; Smits, F.M.A.; Rossum, W.L. van; Huizing, A.

2010-01-01

RF systems based on modular architectures have the potential of better re-use of technology, decreasing development time, and decreasing life cycle cost. Moreover, modular architectures provide scalability, allowing low cost upgrades and adaptability to different platforms. To achieve maximum

Scalable optical quantum computer

Energy Technology Data Exchange (ETDEWEB)

Manykin, E A; Mel' nichenko, E V [Institute for Superconductivity and Solid-State Physics, Russian Research Centre ' Kurchatov Institute' , Moscow (Russian Federation)

2014-12-31

A way of designing a scalable optical quantum computer based on the photon echo effect is proposed. Individual rare earth ions Pr{sup 3+}, regularly located in the lattice of the orthosilicate (Y{sub 2}SiO{sub 5}) crystal, are suggested to be used as optical qubits. Operations with qubits are performed using coherent and incoherent laser pulses. The operation protocol includes both the method of measurement-based quantum computations and the technique of optical computations. Modern hybrid photon echo protocols, which provide a sufficient quantum efficiency when reading recorded states, are considered as most promising for quantum computations and communications. (quantum computer)

Scalable Techniques for Formal Verification

CERN Document Server

Ray, Sandip

2010-01-01

This book presents state-of-the-art approaches to formal verification techniques to seamlessly integrate different formal verification methods within a single logical foundation. It should benefit researchers and practitioners looking to get a broad overview of the spectrum of formal verification techniques, as well as approaches to combining such techniques within a single framework. Coverage includes a range of case studies showing how such combination is fruitful in developing a scalable verification methodology for industrial designs. This book outlines both theoretical and practical issue

Scalable Optical-Fiber Communication Networks

Science.gov (United States)

Chow, Edward T.; Peterson, John C.

1993-01-01

Scalable arbitrary fiber extension network (SAFEnet) is conceptual fiber-optic communication network passing digital signals among variety of computers and input/output devices at rates from 200 Mb/s to more than 100 Gb/s. Intended for use with very-high-speed computers and other data-processing and communication systems in which message-passing delays must be kept short. Inherent flexibility makes it possible to match performance of network to computers by optimizing configuration of interconnections. In addition, interconnections made redundant to provide tolerance to faults.

Space Situational Awareness Data Processing Scalability Utilizing Google Cloud Services

Science.gov (United States)

Greenly, D.; Duncan, M.; Wysack, J.; Flores, F.

Space Situational Awareness (SSA) is a fundamental and critical component of current space operations. The term SSA encompasses the awareness, understanding and predictability of all objects in space. As the population of orbital space objects and debris increases, the number of collision avoidance maneuvers grows and prompts the need for accurate and timely process measures. The SSA mission continually evolves to near real-time assessment and analysis demanding the need for higher processing capabilities. By conventional methods, meeting these demands requires the integration of new hardware to keep pace with the growing complexity of maneuver planning algorithms. SpaceNav has implemented a highly scalable architecture that will track satellites and debris by utilizing powerful virtual machines on the Google Cloud Platform. SpaceNav algorithms for processing CDMs outpace conventional means. A robust processing environment for tracking data, collision avoidance maneuvers and various other aspects of SSA can be created and deleted on demand. Migrating SpaceNav tools and algorithms into the Google Cloud Platform will be discussed and the trials and tribulations involved. Information will be shared on how and why certain cloud products were used as well as integration techniques that were implemented. Key items to be presented are: 1.Scientific algorithms and SpaceNav tools integrated into a scalable architecture a) Maneuver Planning b) Parallel Processing c) Monte Carlo Simulations d) Optimization Algorithms e) SW Application Development/Integration into the Google Cloud Platform 2. Compute Engine Processing a) Application Engine Automated Processing b) Performance testing and Performance Scalability c) Cloud MySQL databases and Database Scalability d) Cloud Data Storage e) Redundancy and Availability

Bitcoin-NG: A Scalable Blockchain Protocol

OpenAIRE

Eyal, Ittay; Gencer, Adem Efe; Sirer, Emin Gun; van Renesse, Robbert

2015-01-01

Cryptocurrencies, based on and led by Bitcoin, have shown promise as infrastructure for pseudonymous online payments, cheap remittance, trustless digital asset exchange, and smart contracts. However, Bitcoin-derived blockchain protocols have inherent scalability limits that trade-off between throughput and latency and withhold the realization of this potential. This paper presents Bitcoin-NG, a new blockchain protocol designed to scale. Based on Bitcoin's blockchain protocol, Bitcoin-NG is By...

SWAP-Assembler: scalable and efficient genome assembly towards thousands of cores.

Science.gov (United States)

Meng, Jintao; Wang, Bingqiang; Wei, Yanjie; Feng, Shengzhong; Balaji, Pavan

2014-01-01

There is a widening gap between the throughput of massive parallel sequencing machines and the ability to analyze these sequencing data. Traditional assembly methods requiring long execution time and large amount of memory on a single workstation limit their use on these massive data. This paper presents a highly scalable assembler named as SWAP-Assembler for processing massive sequencing data using thousands of cores, where SWAP is an acronym for Small World Asynchronous Parallel model. In the paper, a mathematical description of multi-step bi-directed graph (MSG) is provided to resolve the computational interdependence on merging edges, and a highly scalable computational framework for SWAP is developed to automatically preform the parallel computation of all operations. Graph cleaning and contig extension are also included for generating contigs with high quality. Experimental results show that SWAP-Assembler scales up to 2048 cores on Yanhuang dataset using only 26 minutes, which is better than several other parallel assemblers, such as ABySS, Ray, and PASHA. Results also show that SWAP-Assembler can generate high quality contigs with good N50 size and low error rate, especially it generated the longest N50 contig sizes for Fish and Yanhuang datasets. In this paper, we presented a highly scalable and efficient genome assembly software, SWAP-Assembler. Compared with several other assemblers, it showed very good performance in terms of scalability and contig quality. This software is available at: https://sourceforge.net/projects/swapassembler.

GoFFish: Graph-Oriented Framework for Foresight and Insight Using Scalable Heuristics

Science.gov (United States)

2015-09-01

A. Biem, E. Bouillet, H. Feng, A. Ranganathan , A. Riabov, O. Verscheure, H. Koutsopoulos, and C. Moran, “Ibm infos- phere streams for scalable, real...Systems and Software. Elsevier, 2013, vol. 86, no. 1, pp. 2–11. [5] A. Biem, E. Bouillet, H. Feng, A. Ranganathan , A. Riabov, O. Verscheure, H...Feng, A. Ranganathan , A. Riabov, O. Verscheure, H. Koutsopoulos, and C. Moran. Ibm infosphere streams for scalable, real-time, intelligent

Highly scalable Ab initio genomic motif identification

KAUST Repository

Marchand, Benoit; Bajic, Vladimir B.; Kaushik, Dinesh

2011-01-01

We present results of scaling an ab initio motif family identification system, Dragon Motif Finder (DMF), to 65,536 processor cores of IBM Blue Gene/P. DMF seeks groups of mutually similar polynucleotide patterns within a set of genomic sequences and builds various motif families from them. Such information is of relevance to many problems in life sciences. Prior attempts to scale such ab initio motif-finding algorithms achieved limited success. We solve the scalability issues using a combination of mixed-mode MPI-OpenMP parallel programming, master-slave work assignment, multi-level workload distribution, multi-level MPI collectives, and serial optimizations. While the scalability of our algorithm was excellent (94% parallel efficiency on 65,536 cores relative to 256 cores on a modest-size problem), the final speedup with respect to the original serial code exceeded 250,000 when serial optimizations are included. This enabled us to carry out many large-scale ab initio motiffinding simulations in a few hours while the original serial code would have needed decades of execution time. Copyright 2011 ACM.

The intergroup protocols: Scalable group communication for the internet

Energy Technology Data Exchange (ETDEWEB)

Berket, Karlo [Univ. of California, Santa Barbara, CA (United States)

2000-12-04

Reliable group ordered delivery of multicast messages in a distributed system is a useful service that simplifies the programming of distributed applications. Such a service helps to maintain the consistency of replicated information and to coordinate the activities of the various processes. With the increasing popularity of the Internet, there is an increasing interest in scaling the protocols that provide this service to the environment of the Internet. The InterGroup protocol suite, described in this dissertation, provides such a service, and is intended for the environment of the Internet with scalability to large numbers of nodes and high latency links. The InterGroup protocols approach the scalability problem from various directions. They redefine the meaning of group membership, allow voluntary membership changes, add a receiver-oriented selection of delivery guarantees that permits heterogeneity of the receiver set, and provide a scalable reliability service. The InterGroup system comprises several components, executing at various sites within the system. Each component provides part of the services necessary to implement a group communication system for the wide-area. The components can be categorized as: (1) control hierarchy, (2) reliable multicast, (3) message distribution and delivery, and (4) process group membership. We have implemented a prototype of the InterGroup protocols in Java, and have tested the system performance in both local-area and wide-area networks.

Temporal Scalability through Adaptive -Band Filter Banks for Robust H.264/MPEG-4 AVC Video Coding

Directory of Open Access Journals (Sweden)

Pau G

2006-01-01

Full Text Available This paper presents different structures that use adaptive -band hierarchical filter banks for temporal scalability. Open-loop and closed-loop configurations are introduced and illustrated using existing video codecs. In particular, it is shown that the H.264/MPEG-4 AVC codec allows us to introduce scalability by frame shuffling operations, thus keeping backward compatibility with the standard. The large set of shuffling patterns introduced here can be exploited to adapt the encoding process to the video content features, as well as to the user equipment and transmission channel characteristics. Furthermore, simulation results show that this scalability is obtained with no degradation in terms of subjective and objective quality in error-free environments, while in error-prone channels the scalable versions provide increased robustness.

Adolescent sexuality education: An appraisal of some scalable ...

African Journals Online (AJOL)

Adolescent sexuality education: An appraisal of some scalable interventions for the Nigerian context. VC Pam. Abstract. Most issues around sexual intercourse are highly sensitive topics in Nigeria. Despite the disturbingly high adolescent HIV prevalence and teenage pregnancy rate in Nigeria, sexuality education is ...

Impact of multiplexed reading scheme on nanocrossbar memristor memory's scalability

International Nuclear Information System (INIS)

Zhu Xuan; Tang Yu-Hua; Wu Jun-Jie; Yi Xun; Wu Chun-Qing

2014-01-01

Nanocrossbar is a potential memory architecture to integrate memristor to achieve large scale and high density memory. However, based on the currently widely-adopted parallel reading scheme, scalability of the nanocrossbar memory is limited, since the overhead of the reading circuits is in proportion with the size of the nanocrossbar component. In this paper, a multiplexed reading scheme is adopted as the foundation of the discussion. Through HSPICE simulation, we reanalyze scalability of the nanocrossbar memristor memory by investigating the impact of various circuit parameters on the output voltage swing as the memory scales to larger size. We find that multiplexed reading maintains sufficient noise margin in large size nanocrossbar memristor memory. In order to improve the scalability of the memory, memristors with nonlinear I—V characteristics and high LRS (low resistive state) resistance should be adopted. (interdisciplinary physics and related areas of science and technology)

Integration of an intelligent systems behavior simulator and a scalable soldier-machine interface

Science.gov (United States)

Johnson, Tony; Manteuffel, Chris; Brewster, Benjamin; Tierney, Terry

2007-04-01

As the Army's Future Combat Systems (FCS) introduce emerging technologies and new force structures to the battlefield, soldiers will increasingly face new challenges in workload management. The next generation warfighter will be responsible for effectively managing robotic assets in addition to performing other missions. Studies of future battlefield operational scenarios involving the use of automation, including the specification of existing and proposed technologies, will provide significant insight into potential problem areas regarding soldier workload. The US Army Tank Automotive Research, Development, and Engineering Center (TARDEC) is currently executing an Army technology objective program to analyze and evaluate the effect of automated technologies and their associated control devices with respect to soldier workload. The Human-Robotic Interface (HRI) Intelligent Systems Behavior Simulator (ISBS) is a human performance measurement simulation system that allows modelers to develop constructive simulations of military scenarios with various deployments of interface technologies in order to evaluate operator effectiveness. One such interface is TARDEC's Scalable Soldier-Machine Interface (SMI). The scalable SMI provides a configurable machine interface application that is capable of adapting to several hardware platforms by recognizing the physical space limitations of the display device. This paper describes the integration of the ISBS and Scalable SMI applications, which will ultimately benefit both systems. The ISBS will be able to use the Scalable SMI to visualize the behaviors of virtual soldiers performing HRI tasks, such as route planning, and the scalable SMI will benefit from stimuli provided by the ISBS simulation environment. The paper describes the background of each system and details of the system integration approach.

Scalable manufacturing processes with soft materials

OpenAIRE

White, Edward; Case, Jennifer; Kramer, Rebecca

2014-01-01

The emerging field of soft robotics will benefit greatly from new scalable manufacturing techniques for responsive materials. Currently, most of soft robotic examples are fabricated one-at-a-time, using techniques borrowed from lithography and 3D printing to fabricate molds. This limits both the maximum and minimum size of robots that can be fabricated, and hinders batch production, which is critical to gain wider acceptance for soft robotic systems. We have identified electrical structures, ...

Randomized Algorithms for Scalable Machine Learning

OpenAIRE

Kleiner, Ariel Jacob

2012-01-01

Many existing procedures in machine learning and statistics are computationally intractable in the setting of large-scale data. As a result, the advent of rapidly increasing dataset sizes, which should be a boon yielding improved statistical performance, instead severely blunts the usefulness of a variety of existing inferential methods. In this work, we use randomness to ameliorate this lack of scalability by reducing complex, computationally difficult inferential problems to larger sets o...

Error-Resilient Unequal Error Protection of Fine Granularity Scalable Video Bitstreams

Science.gov (United States)

Cai, Hua; Zeng, Bing; Shen, Guobin; Xiong, Zixiang; Li, Shipeng

2006-12-01

This paper deals with the optimal packet loss protection issue for streaming the fine granularity scalable (FGS) video bitstreams over IP networks. Unlike many other existing protection schemes, we develop an error-resilient unequal error protection (ER-UEP) method that adds redundant information optimally for loss protection and, at the same time, cancels completely the dependency among bitstream after loss recovery. In our ER-UEP method, the FGS enhancement-layer bitstream is first packetized into a group of independent and scalable data packets. Parity packets, which are also scalable, are then generated. Unequal protection is finally achieved by properly shaping the data packets and the parity packets. We present an algorithm that can optimally allocate the rate budget between data packets and parity packets, together with several simplified versions that have lower complexity. Compared with conventional UEP schemes that suffer from bit contamination (caused by the bit dependency within a bitstream), our method guarantees successful decoding of all received bits, thus leading to strong error-resilience (at any fixed channel bandwidth) and high robustness (under varying and/or unclean channel conditions).

Scalable Robust Principal Component Analysis Using Grassmann Averages

DEFF Research Database (Denmark)

Hauberg, Søren; Feragen, Aasa; Enficiaud, Raffi

2016-01-01

In large datasets, manual data verification is impossible, and we must expect the number of outliers to increase with data size. While principal component analysis (PCA) can reduce data size, and scalable solutions exist, it is well-known that outliers can arbitrarily corrupt the results. Unfortu...

MicROS-drt: supporting real-time and scalable data distribution in distributed robotic systems.

Science.gov (United States)

Ding, Bo; Wang, Huaimin; Fan, Zedong; Zhang, Pengfei; Liu, Hui

A primary requirement in distributed robotic software systems is the dissemination of data to all interested collaborative entities in a timely and scalable manner. However, providing such a service in a highly dynamic and resource-limited robotic environment is a challenging task, and existing robot software infrastructure has limitations in this aspect. This paper presents a novel robot software infrastructure, micROS-drt, which supports real-time and scalable data distribution. The solution is based on a loosely coupled data publish-subscribe model with the ability to support various time-related constraints. And to realize this model, a mature data distribution standard, the data distribution service for real-time systems (DDS), is adopted as the foundation of the transport layer of this software infrastructure. By elaborately adapting and encapsulating the capability of the underlying DDS middleware, micROS-drt can meet the requirement of real-time and scalable data distribution in distributed robotic systems. Evaluation results in terms of scalability, latency jitter and transport priority as well as the experiment on real robots validate the effectiveness of this work.

A Testbed for Highly-Scalable Mission Critical Information Systems

National Research Council Canada - National Science Library

Birman, Kenneth P

2005-01-01

... systems in a networked environment. Headed by Professor Ken Birman, the project is exploring a novel fusion of classical protocols for reliable multicast communication with a new style of peer-to-peer protocol called scalable "gossip...

Design and thermal performances of a scalable linear Fresnel reflector solar system

International Nuclear Information System (INIS)

Zhu, Yanqing; Shi, Jifu; Li, Yujian; Wang, Leilei; Huang, Qizhang; Xu, Gang

2017-01-01

Highlights: • A scalable linear Fresnel reflector which can supply different temperatures is proposed. • Inclination design of the mechanical structure is used to reduce the end losses. • The maximum thermal efficiency of 64% is achieved in Guangzhou. - Abstract: This paper proposes a scalable linear Fresnel reflector (SLFR) solar system. The optical mirror field which contains an array of linear plat mirrors closed to each other is designed to eliminate the inter-low shading and blocking. Scalable mechanical mirror support which can place different number of mirrors is designed to supply different temperatures. The mechanical structure can be inclined to reduce the end losses. Finally, the thermal efficiency of the SLFR with two stage mirrors is tested. After adjustment, the maximum thermal efficiency of 64% is obtained and the mean thermal efficiency is higher than that before adjustment. The results indicate that the end losses have been reduced effectively by the inclination design and excellent thermal performance can be obtained by the SLFR after adjustment.

A Scalable Smart Meter Data Generator Using Spark

DEFF Research Database (Denmark)

Iftikhar, Nadeem; Liu, Xiufeng; Danalachi, Sergiu

2017-01-01

Today, smart meters are being used worldwide. As a matter of fact smart meters produce large volumes of data. Thus, it is important for smart meter data management and analytics systems to process petabytes of data. Benchmarking and testing of these systems require scalable data, however, it can ...

A Massively Scalable Architecture for Instant Messaging & Presence

NARCIS (Netherlands)

Schippers, Jorrit; Remke, Anne Katharina Ingrid; Punt, Henk; Wegdam, M.; Haverkort, Boudewijn R.H.M.; Thomas, N.; Bradley, J.; Knottenbelt, W.; Dingle, N.; Harder, U.

2010-01-01

This paper analyzes the scalability of Instant Messaging & Presence (IM&P) architectures. We take a queueing-based modelling and analysis approach to ��?nd the bottlenecks of the current IM&P architecture at the Dutch social network Hyves, as well as of alternative architectures. We use the

A Scalable Cloud Library Empowering Big Data Management, Diagnosis, and Visualization of Cloud-Resolving Models

Science.gov (United States)

Zhou, S.; Tao, W. K.; Li, X.; Matsui, T.; Sun, X. H.; Yang, X.

2015-12-01

A cloud-resolving model (CRM) is an atmospheric numerical model that can numerically resolve clouds and cloud systems at 0.25~5km horizontal grid spacings. The main advantage of the CRM is that it can allow explicit interactive processes between microphysics, radiation, turbulence, surface, and aerosols without subgrid cloud fraction, overlapping and convective parameterization. Because of their fine resolution and complex physical processes, it is challenging for the CRM community to i) visualize/inter-compare CRM simulations, ii) diagnose key processes for cloud-precipitation formation and intensity, and iii) evaluate against NASA's field campaign data and L1/L2 satellite data products due to large data volume (~10TB) and complexity of CRM's physical processes. We have been building the Super Cloud Library (SCL) upon a Hadoop framework, capable of CRM database management, distribution, visualization, subsetting, and evaluation in a scalable way. The current SCL capability includes (1) A SCL data model enables various CRM simulation outputs in NetCDF, including the NASA-Unified Weather Research and Forecasting (NU-WRF) and Goddard Cumulus Ensemble (GCE) model, to be accessed and processed by Hadoop, (2) A parallel NetCDF-to-CSV converter supports NU-WRF and GCE model outputs, (3) A technique visualizes Hadoop-resident data with IDL, (4) A technique subsets Hadoop-resident data, compliant to the SCL data model, with HIVE or Impala via HUE's Web interface, (5) A prototype enables a Hadoop MapReduce application to dynamically access and process data residing in a parallel file system, PVFS2 or CephFS, where high performance computing (HPC) simulation outputs such as NU-WRF's and GCE's are located. We are testing Apache Spark to speed up SCL data processing and analysis.With the SCL capabilities, SCL users can conduct large-domain on-demand tasks without downloading voluminous CRM datasets and various observations from NASA Field Campaigns and Satellite data to a

Scalable privacy-preserving big data aggregation mechanism

Directory of Open Access Journals (Sweden)

Dapeng Wu

2016-08-01

Full Text Available As the massive sensor data generated by large-scale Wireless Sensor Networks (WSNs recently become an indispensable part of ‘Big Data’, the collection, storage, transmission and analysis of the big sensor data attract considerable attention from researchers. Targeting the privacy requirements of large-scale WSNs and focusing on the energy-efficient collection of big sensor data, a Scalable Privacy-preserving Big Data Aggregation (Sca-PBDA method is proposed in this paper. Firstly, according to the pre-established gradient topology structure, sensor nodes in the network are divided into clusters. Secondly, sensor data is modified by each node according to the privacy-preserving configuration message received from the sink. Subsequently, intra- and inter-cluster data aggregation is employed during the big sensor data reporting phase to reduce energy consumption. Lastly, aggregated results are recovered by the sink to complete the privacy-preserving big data aggregation. Simulation results validate the efficacy and scalability of Sca-PBDA and show that the big sensor data generated by large-scale WSNs is efficiently aggregated to reduce network resource consumption and the sensor data privacy is effectively protected to meet the ever-growing application requirements.

Towards Scalable Graph Computation on Mobile Devices.

Science.gov (United States)

Chen, Yiqi; Lin, Zhiyuan; Pienta, Robert; Kahng, Minsuk; Chau, Duen Horng

2014-10-01

Mobile devices have become increasingly central to our everyday activities, due to their portability, multi-touch capabilities, and ever-improving computational power. Such attractive features have spurred research interest in leveraging mobile devices for computation. We explore a novel approach that aims to use a single mobile device to perform scalable graph computation on large graphs that do not fit in the device's limited main memory, opening up the possibility of performing on-device analysis of large datasets, without relying on the cloud. Based on the familiar memory mapping capability provided by today's mobile operating systems, our approach to scale up computation is powerful and intentionally kept simple to maximize its applicability across the iOS and Android platforms. Our experiments demonstrate that an iPad mini can perform fast computation on large real graphs with as many as 272 million edges (Google+ social graph), at a speed that is only a few times slower than a 13″ Macbook Pro. Through creating a real world iOS app with this technique, we demonstrate the strong potential application for scalable graph computation on a single mobile device using our approach.

Towards Scalable Graph Computation on Mobile Devices

Science.gov (United States)

Chen, Yiqi; Lin, Zhiyuan; Pienta, Robert; Kahng, Minsuk; Chau, Duen Horng

2015-01-01

Mobile devices have become increasingly central to our everyday activities, due to their portability, multi-touch capabilities, and ever-improving computational power. Such attractive features have spurred research interest in leveraging mobile devices for computation. We explore a novel approach that aims to use a single mobile device to perform scalable graph computation on large graphs that do not fit in the device's limited main memory, opening up the possibility of performing on-device analysis of large datasets, without relying on the cloud. Based on the familiar memory mapping capability provided by today's mobile operating systems, our approach to scale up computation is powerful and intentionally kept simple to maximize its applicability across the iOS and Android platforms. Our experiments demonstrate that an iPad mini can perform fast computation on large real graphs with as many as 272 million edges (Google+ social graph), at a speed that is only a few times slower than a 13″ Macbook Pro. Through creating a real world iOS app with this technique, we demonstrate the strong potential application for scalable graph computation on a single mobile device using our approach. PMID:25859564

NPTool: Towards Scalability and Reliability of Business Process Management

Science.gov (United States)

Braghetto, Kelly Rosa; Ferreira, João Eduardo; Pu, Calton

Currently one important challenge in business process management is provide at the same time scalability and reliability of business process executions. This difficulty becomes more accentuated when the execution control assumes complex countless business processes. This work presents NavigationPlanTool (NPTool), a tool to control the execution of business processes. NPTool is supported by Navigation Plan Definition Language (NPDL), a language for business processes specification that uses process algebra as formal foundation. NPTool implements the NPDL language as a SQL extension. The main contribution of this paper is a description of the NPTool showing how the process algebra features combined with a relational database model can be used to provide a scalable and reliable control in the execution of business processes. The next steps of NPTool include reuse of control-flow patterns and support to data flow management.

Developing Scalable Information Security Systems

Directory of Open Access Journals (Sweden)

Valery Konstantinovich Ablekov

2013-06-01

Full Text Available Existing physical security systems has wide range of lacks, including: high cost, a large number of vulnerabilities, problems of modification and support system. This paper covers an actual problem of developing systems without this list of drawbacks. The paper presents the architecture of the information security system, which operates through the network protocol TCP/IP, including the ability to connect different types of devices and integration with existing security systems. The main advantage is a significant increase in system reliability, scalability, both vertically and horizontally, with minimal cost of both financial and time resources.

Moving NASA Remote Sensing Data to the GIS Environment for Health Studies

Science.gov (United States)

Vicente, Gilberto A.; Maynard, Nancy G.

2003-01-01

There has been an increasing demand by the health community for improved data on many different environmental factors relevant to the links between the environment and disease occurrence and transmission. These data are important for GIS-based monitoring, risk mapping, and surveillance of epidemiological parameters on a large number of different spatial, temporal, and spectral resolutions. Accordingly, NASA is developing new approaches to data collection and distribution in order to improve access to multiple sources of data streams to increase spatial and temporal coverage. Methods are being developed to incorporate different, scalable capabilities to handle multiple data sources by adding, deleting and replacing components as required as well as associated tools for their management. An approach has been to search for innovative solutions focused on the creation, use and manipulation of data stored in many different archives. These include data transformation and combination as well as data and information tools that can assist the public health and science community to use existing and anticipated products in new and flexible ways. This presentation will provide an inventory of geophysical parameters derived from satellite remote sensing sensors that are useful for GIS-based public health studies. The presentation will also discuss the physical and scientific limitations of access to and use of these data for health applications such as resolution and format differences, lack of software interoperability, data access problems. Finally, there will be a summary of the recent steps the NASA program has taken to bring NASA-generated satellite products to a wider range of users in the GIS community.

Accounting Fundamentals and the Variation of Stock Price: Factoring in the Investment Scalability

OpenAIRE

Sumiyana, Sumiyana; Baridwan, Zaki; Sugiri, Slamet; Hartono, Jogiyanto

2010-01-01

This study develops a new return model with respect to accounting fundamentals. The new return model is based on Chen and Zhang (2007). This study takes into account theinvestment scalability information. Specifically, this study splitsthe scale of firm’s operations into short-run and long-runinvestment scalabilities. We document that five accounting fun-damentals explain the variation of annual stock return. Thefactors, comprised book value, earnings yield, short-run andlong-run investment s...

Cascaded column generation for scalable predictive demand side management

NARCIS (Netherlands)

Toersche, Hermen; Molderink, Albert; Hurink, Johann L.; Smit, Gerardus Johannes Maria

2014-01-01

We propose a nested Dantzig-Wolfe decomposition, combined with dynamic programming, for the distributed scheduling of a large heterogeneous fleet of residential appliances with nonlinear behavior. A cascaded column generation approach gives a scalable optimization strategy, provided that the problem

Impact of packet losses in scalable 3D holoscopic video coding

Science.gov (United States)

Conti, Caroline; Nunes, Paulo; Ducla Soares, Luís.

2014-05-01

Holoscopic imaging became a prospective glassless 3D technology to provide more natural 3D viewing experiences to the end user. Additionally, holoscopic systems also allow new post-production degrees of freedom, such as controlling the plane of focus or the viewing angle presented to the user. However, to successfully introduce this technology into the consumer market, a display scalable coding approach is essential to achieve backward compatibility with legacy 2D and 3D displays. Moreover, to effectively transmit 3D holoscopic content over error-prone networks, e.g., wireless networks or the Internet, error resilience techniques are required to mitigate the impact of data impairments in the user quality perception. Therefore, it is essential to deeply understand the impact of packet losses in terms of decoding video quality for the specific case of 3D holoscopic content, notably when a scalable approach is used. In this context, this paper studies the impact of packet losses when using a three-layer display scalable 3D holoscopic video coding architecture previously proposed, where each layer represents a different level of display scalability (i.e., L0 - 2D, L1 - stereo or multiview, and L2 - full 3D holoscopic). For this, a simple error concealment algorithm is used, which makes use of inter-layer redundancy between multiview and 3D holoscopic content and the inherent correlation of the 3D holoscopic content to estimate lost data. Furthermore, a study of the influence of 2D views generation parameters used in lower layers on the performance of the used error concealment algorithm is also presented.

A repeatable and scalable fabrication method for sharp, hollow silicon microneedles

Science.gov (United States)

Kim, H.; Theogarajan, L. S.; Pennathur, S.

2018-03-01

Scalability and manufacturability are impeding the mass commercialization of microneedles in the medical field. Specifically, microneedle geometries need to be sharp, beveled, and completely controllable, difficult to achieve with microelectromechanical fabrication techniques. In this work, we performed a parametric study using silicon etch chemistries to optimize the fabrication of scalable and manufacturable beveled silicon hollow microneedles. We theoretically verified our parametric results with diffusion reaction equations and created a design guideline for a various set of miconeedles (80-160 µm needle base width, 100-1000 µm pitch, 40-50 µm inner bore diameter, and 150-350 µm height) to show the repeatability, scalability, and manufacturability of our process. As a result, hollow silicon microneedles with any dimensions can be fabricated with less than 2% non-uniformity across a wafer and 5% deviation between different processes. The key to achieving such high uniformity and consistency is a non-agitated HF-HNO3 bath, silicon nitride masks, and surrounding silicon filler materials with well-defined dimensions. Our proposed method is non-labor intensive, well defined by theory, and straightforward for wafer scale mass production, opening doors to a plethora of potential medical and biosensing applications.

Fabrication of Scalable Indoor Light Energy Harvester and Study for Agricultural IoT Applications

International Nuclear Information System (INIS)

Watanabe, M; Nakamura, A; Kunii, A; Kusano, K; Futagawa, M

2015-01-01

A scalable indoor light energy harvester was fabricated by microelectromechanical system (MEMS) and printing hybrid technology and evaluated for agricultural IoT applications under different environmental input power density conditions, such as outdoor farming under the sun, greenhouse farming under scattered lighting, and a plant factory under LEDs. We fabricated and evaluated a dye- sensitized-type solar cell (DSC) as a low cost and “scalable” optical harvester device. We developed a transparent conductive oxide (TCO)-less process with a honeycomb metal mesh substrate fabricated by MEMS technology. In terms of the electrical and optical properties, we achieved scalable harvester output power by cell area sizing. Second, we evaluated the dependence of the input power scalable characteristics on the input light intensity, spectrum distribution, and light inlet direction angle, because harvested environmental input power is unstable. The TiO 2 fabrication relied on nanoimprint technology, which was designed for optical optimization and fabrication, and we confirmed that the harvesters are robust to a variety of environments. Finally, we studied optical energy harvesting applications for agricultural IoT systems. These scalable indoor light harvesters could be used in many applications and situations in smart agriculture. (paper)

Fabrication of Scalable Indoor Light Energy Harvester and Study for Agricultural IoT Applications

Science.gov (United States)

Watanabe, M.; Nakamura, A.; Kunii, A.; Kusano, K.; Futagawa, M.

2015-12-01

A scalable indoor light energy harvester was fabricated by microelectromechanical system (MEMS) and printing hybrid technology and evaluated for agricultural IoT applications under different environmental input power density conditions, such as outdoor farming under the sun, greenhouse farming under scattered lighting, and a plant factory under LEDs. We fabricated and evaluated a dye- sensitized-type solar cell (DSC) as a low cost and “scalable” optical harvester device. We developed a transparent conductive oxide (TCO)-less process with a honeycomb metal mesh substrate fabricated by MEMS technology. In terms of the electrical and optical properties, we achieved scalable harvester output power by cell area sizing. Second, we evaluated the dependence of the input power scalable characteristics on the input light intensity, spectrum distribution, and light inlet direction angle, because harvested environmental input power is unstable. The TiO2 fabrication relied on nanoimprint technology, which was designed for optical optimization and fabrication, and we confirmed that the harvesters are robust to a variety of environments. Finally, we studied optical energy harvesting applications for agricultural IoT systems. These scalable indoor light harvesters could be used in many applications and situations in smart agriculture.

EvAg: A Scalable Peer-to-Peer Evolutionary Algorithm

NARCIS (Netherlands)

Laredo, J.L.J.; Eiben, A.E.; van Steen, M.R.; Merelo, J.J.

2010-01-01

This paper studies the scalability of an Evolutionary Algorithm (EA) whose population is structured by means of a gossiping protocol and where the evolutionary operators act exclusively within the local neighborhoods. This makes the algorithm inherently suited for parallel execution in a

GPU-based Scalable Volumetric Reconstruction for Multi-view Stereo

Energy Technology Data Exchange (ETDEWEB)

Kim, H; Duchaineau, M; Max, N

2011-09-21

We present a new scalable volumetric reconstruction algorithm for multi-view stereo using a graphics processing unit (GPU). It is an effectively parallelized GPU algorithm that simultaneously uses a large number of GPU threads, each of which performs voxel carving, in order to integrate depth maps with images from multiple views. Each depth map, triangulated from pair-wise semi-dense correspondences, represents a view-dependent surface of the scene. This algorithm also provides scalability for large-scale scene reconstruction in a high resolution voxel grid by utilizing streaming and parallel computation. The output is a photo-realistic 3D scene model in a volumetric or point-based representation. We demonstrate the effectiveness and the speed of our algorithm with a synthetic scene and real urban/outdoor scenes. Our method can also be integrated with existing multi-view stereo algorithms such as PMVS2 to fill holes or gaps in textureless regions.

Parallel scalability and efficiency of vortex particle method for aeroelasticity analysis of bluff bodies

Science.gov (United States)

Tolba, Khaled Ibrahim; Morgenthal, Guido

2018-01-01

This paper presents an analysis of the scalability and efficiency of a simulation framework based on the vortex particle method. The code is applied for the numerical aerodynamic analysis of line-like structures. The numerical code runs on multicore CPU and GPU architectures using OpenCL framework. The focus of this paper is the analysis of the parallel efficiency and scalability of the method being applied to an engineering test case, specifically the aeroelastic response of a long-span bridge girder at the construction stage. The target is to assess the optimal configuration and the required computer architecture, such that it becomes feasible to efficiently utilise the method within the computational resources available for a regular engineering office. The simulations and the scalability analysis are performed on a regular gaming type computer.

A scalable infrastructure for CMS data analysis based on OpenStack Cloud and Gluster file system

Science.gov (United States)

Toor, S.; Osmani, L.; Eerola, P.; Kraemer, O.; Lindén, T.; Tarkoma, S.; White, J.

2014-06-01

The challenge of providing a resilient and scalable computational and data management solution for massive scale research environments requires continuous exploration of new technologies and techniques. In this project the aim has been to design a scalable and resilient infrastructure for CERN HEP data analysis. The infrastructure is based on OpenStack components for structuring a private Cloud with the Gluster File System. We integrate the state-of-the-art Cloud technologies with the traditional Grid middleware infrastructure. Our test results show that the adopted approach provides a scalable and resilient solution for managing resources without compromising on performance and high availability.

A scalable infrastructure for CMS data analysis based on OpenStack Cloud and Gluster file system

International Nuclear Information System (INIS)

Toor, S; Eerola, P; Kraemer, O; Lindén, T; Osmani, L; Tarkoma, S; White, J

2014-01-01

The challenge of providing a resilient and scalable computational and data management solution for massive scale research environments requires continuous exploration of new technologies and techniques. In this project the aim has been to design a scalable and resilient infrastructure for CERN HEP data analysis. The infrastructure is based on OpenStack components for structuring a private Cloud with the Gluster File System. We integrate the state-of-the-art Cloud technologies with the traditional Grid middleware infrastructure. Our test results show that the adopted approach provides a scalable and resilient solution for managing resources without compromising on performance and high availability.

Scalable Performance Measurement and Analysis

Energy Technology Data Exchange (ETDEWEB)

Gamblin, Todd [Univ. of North Carolina, Chapel Hill, NC (United States)

2009-01-01

Concurrency levels in large-scale, distributed-memory supercomputers are rising exponentially. Modern machines may contain 100,000 or more microprocessor cores, and the largest of these, IBM's Blue Gene/L, contains over 200,000 cores. Future systems are expected to support millions of concurrent tasks. In this dissertation, we focus on efficient techniques for measuring and analyzing the performance of applications running on very large parallel machines. Tuning the performance of large-scale applications can be a subtle and time-consuming task because application developers must measure and interpret data from many independent processes. While the volume of the raw data scales linearly with the number of tasks in the running system, the number of tasks is growing exponentially, and data for even small systems quickly becomes unmanageable. Transporting performance data from so many processes over a network can perturb application performance and make measurements inaccurate, and storing such data would require a prohibitive amount of space. Moreover, even if it were stored, analyzing the data would be extremely time-consuming. In this dissertation, we present novel methods for reducing performance data volume. The first draws on multi-scale wavelet techniques from signal processing to compress systemwide, time-varying load-balance data. The second uses statistical sampling to select a small subset of running processes to generate low-volume traces. A third approach combines sampling and wavelet compression to stratify performance data adaptively at run-time and to reduce further the cost of sampled tracing. We have integrated these approaches into Libra, a toolset for scalable load-balance analysis. We present Libra and show how it can be used to analyze data from large scientific applications scalably.

Heat-treated stainless steel felt as scalable anode material for bioelectrochemical systems.

Science.gov (United States)

Guo, Kun; Soeriyadi, Alexander H; Feng, Huajun; Prévoteau, Antonin; Patil, Sunil A; Gooding, J Justin; Rabaey, Korneel

2015-11-01

This work reports a simple and scalable method to convert stainless steel (SS) felt into an effective anode for bioelectrochemical systems (BESs) by means of heat treatment. X-ray photoelectron spectroscopy and cyclic voltammetry elucidated that the heat treatment generated an iron oxide rich layer on the SS felt surface. The iron oxide layer dramatically enhanced the electroactive biofilm formation on SS felt surface in BESs. Consequently, the sustained current densities achieved on the treated electrodes (1 cm(2)) were around 1.5±0.13 mA/cm(2), which was seven times higher than the untreated electrodes (0.22±0.04 mA/cm(2)). To test the scalability of this material, the heat-treated SS felt was scaled up to 150 cm(2) and similar current density (1.5 mA/cm(2)) was achieved on the larger electrode. The low cost, straightforwardness of the treatment, high conductivity and high bioelectrocatalytic performance make heat-treated SS felt a scalable anodic material for BESs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Scalable Frequent Subgraph Mining

KAUST Repository

Abdelhamid, Ehab

2017-06-19

A graph is a data structure that contains a set of nodes and a set of edges connecting these nodes. Nodes represent objects while edges model relationships among these objects. Graphs are used in various domains due to their ability to model complex relations among several objects. Given an input graph, the Frequent Subgraph Mining (FSM) task finds all subgraphs with frequencies exceeding a given threshold. FSM is crucial for graph analysis, and it is an essential building block in a variety of applications, such as graph clustering and indexing. FSM is computationally expensive, and its existing solutions are extremely slow. Consequently, these solutions are incapable of mining modern large graphs. This slowness is caused by the underlying approaches of these solutions which require finding and storing an excessive amount of subgraph matches. This dissertation proposes a scalable solution for FSM that avoids the limitations of previous work. This solution is composed of four components. The first component is a single-threaded technique which, for each candidate subgraph, needs to find only a minimal number of matches. The second component is a scalable parallel FSM technique that utilizes a novel two-phase approach. The first phase quickly builds an approximate search space, which is then used by the second phase to optimize and balance the workload of the FSM task. The third component focuses on accelerating frequency evaluation, which is a critical step in FSM. To do so, a machine learning model is employed to predict the type of each graph node, and accordingly, an optimized method is selected to evaluate that node. The fourth component focuses on mining dynamic graphs, such as social networks. To this end, an incremental index is maintained during the dynamic updates. Only this index is processed and updated for the majority of graph updates. Consequently, search space is significantly pruned and efficiency is improved. The empirical evaluation shows that the

SIRTF Tools for DIRT

Science.gov (United States)

Pound, M. W.; Wolfire, M. G.; Amarnath, N. S.

2004-07-01

The Dust InfraRed ToolBox (DIRT - a part of the Web Infrared ToolShed, or WITS {http://dustem.astro.umd.edu}) is a Java applet for modeling astrophysical processes in circumstellar shells around young and evolved stars. DIRT has been used by the astrophysics community for about 5 years. Users can automatically and efficiently search grids of pre-calculated models to fit their data. A large set of physical parameters and dust types are included in the model database, which contains over 500,000 models. We are adding new functionality to DIRT to support new missions like SIRTF and SOFIA. A new Instrument module allows for plotting of the model points convolved with the spatial and spectral responses of the selected instrument. This lets users better fit data from specific instruments. Currently, we have implemented modules for the Infrared Array Camera (IRAC) and Multiband Imaging Photometer (MIPS) on SIRTF. The models are based on the dust radiation transfer code of Wolfire & Cassinelli (1986) which accounts for multiple grain sizes and compositions. The model outputs are averaged over the instrument bands using the same weighting (νFν = constant) as the SIRTF data pipeline which allows the SIRTF data products to be compared directly with the model database. This work was supported in part by a NASA AISRP grant NAG 5-10751 and the SIRTF Legacy Science Program provided by NASA through an award issued by JPL under NASA contract 1407.

Design for scalability in 3D computer graphics architectures

DEFF Research Database (Denmark)

Holten-Lund, Hans Erik

2002-01-01

This thesis describes useful methods and techniques for designing scalable hybrid parallel rendering architectures for 3D computer graphics. Various techniques for utilizing parallelism in a pipelines system are analyzed. During the Ph.D study a prototype 3D graphics architecture named Hybris has...

Scalable electro-photonic integration concept based on polymer waveguides

NARCIS (Netherlands)

Bosman, E.; Steenberge, G. van; Boersma, A.; Wiegersma, S.; Harmsma, P.J.; Karppinen, M.; Korhonen, T.; Offrein, B.J.; Dangel, R.; Daly, A.; Ortsiefer, M.; Justice, J.; Corbett, B.; Dorrestein, S.; Duis, J.

2016-01-01

A novel method for fabricating a single mode optical interconnection platform is presented. The method comprises the miniaturized assembly of optoelectronic single dies, the scalable fabrication of polymer single mode waveguides and the coupling to glass fiber arrays providing the I/O's. The low

Scalable Content Authentication in H.264/SVC Videos Using Perceptual Hashing based on Dempster-Shafer theory

Directory of Open Access Journals (Sweden)

Ye Dengpan

2012-09-01

Full Text Available The content authenticity of the multimedia delivery is important issue with rapid development and widely used of multimedia technology. Till now many authentication solutions had been proposed, such as cryptology and watermarking based methods. However, in latest heterogeneous network the video stream transmission has been coded in scalable way such as H.264/SVC, there is still no good authentication solution. In this paper, we firstly summarized related works and proposed a scalable content authentication scheme using a ratio of different energy (RDE based perceptual hashing in Q/S dimension, which is used Dempster-Shafer theory and combined with the latest scalable video coding (H.264/SVC construction. The idea of aldquo;sign once and verify in scalable wayardquo; can be realized. Comparing with previous methods, the proposed scheme based on perceptual hashing outperforms previous works in uncertainty (robustness and efficiencies in the H.264/SVC video streams. At last, the experiment results verified the performance of our scheme.

Towards Bandwidth Scalable Transceiver Technology for Optical Metro-Access Networks

DEFF Research Database (Denmark)

Spolitis, Sandis; Bobrovs, Vjaceslavs; Wagner, Christoph

2015-01-01

sliceable transceiver for 1 Gbit/s non-return to zero (NRZ) signal sliced into two slices is presented. Digital signal processing (DSP) power consumption and latency values for proposed sliceable transceiver technique are also discussed. In this research post FEC with 7% overhead error free transmission has......Massive fiber-to-the-home network deployment is creating a challenge for telecommunications network operators: exponential increase of the power consumption at the central offices and a never ending quest for equipment upgrades operating at higher bandwidth. In this paper, we report on flexible...... signal slicing technique, which allows transmission of high-bandwidth signals via low bandwidth electrical and optoelectrical equipment. The presented signal slicing technique is highly scalable in terms of bandwidth which is determined by the number of slices used. In this paper performance of scalable...

Proof of Stake Blockchain: Performance and Scalability for Groupware Communications

DEFF Research Database (Denmark)

Spasovski, Jason; Eklund, Peter

2017-01-01

A blockchain is a distributed transaction ledger, a disruptive technology that creates new possibilities for digital ecosystems. The blockchain ecosystem maintains an immutable transaction record to support many types of digital services. This paper compares the performance and scalability of a web......-based groupware communication application using both non-blockchain and blockchain technologies. Scalability is measured where message load is synthesized over two typical communication topologies. The first is 1 to n network -- a typical client-server or star-topology with a central vertex (server) receiving all...... messages from the remaining n - 1 vertices (clients). The second is a more naturally occurring scale-free network topology, where multiple communication hubs are distributed throughout the network. System performance is tested with both blockchain and non-blockchain solutions using multiple cloud computing...

SCALABLE TIME SERIES CHANGE DETECTION FOR BIOMASS MONITORING USING GAUSSIAN PROCESS

Data.gov (United States)

National Aeronautics and Space Administration — SCALABLE TIME SERIES CHANGE DETECTION FOR BIOMASS MONITORING USING GAUSSIAN PROCESS VARUN CHANDOLA AND RANGA RAJU VATSAVAI Abstract. Biomass monitoring,...

Big data integration: scalability and sustainability

KAUST Repository

Zhang, Zhang

2016-01-26

Integration of various types of omics data is critically indispensable for addressing most important and complex biological questions. In the era of big data, however, data integration becomes increasingly tedious, time-consuming and expensive, posing a significant obstacle to fully exploit the wealth of big biological data. Here we propose a scalable and sustainable architecture that integrates big omics data through community-contributed modules. Community modules are contributed and maintained by different committed groups and each module corresponds to a specific data type, deals with data collection, processing and visualization, and delivers data on-demand via web services. Based on this community-based architecture, we build Information Commons for Rice (IC4R; http://ic4r.org), a rice knowledgebase that integrates a variety of rice omics data from multiple community modules, including genome-wide expression profiles derived entirely from RNA-Seq data, resequencing-based genomic variations obtained from re-sequencing data of thousands of rice varieties, plant homologous genes covering multiple diverse plant species, post-translational modifications, rice-related literatures, and community annotations. Taken together, such architecture achieves integration of different types of data from multiple community-contributed modules and accordingly features scalable, sustainable and collaborative integration of big data as well as low costs for database update and maintenance, thus helpful for building IC4R into a comprehensive knowledgebase covering all aspects of rice data and beneficial for both basic and translational researches.

ENDEAVOUR: A Scalable SDN Architecture for Real-World IXPs

KAUST Repository

Antichi, Gianni

2017-10-25

Innovation in interdomain routing has remained stagnant for over a decade. Recently, IXPs have emerged as economically-advantageous interconnection points for reducing path latencies and exchanging ever increasing traffic volumes among, possibly, hundreds of networks. Given their far-reaching implications on interdomain routing, IXPs are the ideal place to foster network innovation and extend the benefits of SDN to the interdomain level. In this paper, we present, evaluate, and demonstrate ENDEAVOUR, an SDN platform for IXPs. ENDEAVOUR can be deployed on a multi-hop IXP fabric, supports a large number of use cases, and is highly-scalable while avoiding broadcast storms. Our evaluation with real data from one of the largest IXPs, demonstrates the benefits and scalability of our solution: ENDEAVOUR requires around 70% fewer rules than alternative SDN solutions thanks to our rule partitioning mechanism. In addition, by providing an open source solution, we invite everyone from the community to experiment (and improve) our implementation as well as adapt it to new use cases.

Programming Scala Scalability = Functional Programming + Objects

CERN Document Server

Wampler, Dean

2009-01-01

Learn how to be more productive with Scala, a new multi-paradigm language for the Java Virtual Machine (JVM) that integrates features of both object-oriented and functional programming. With this book, you'll discover why Scala is ideal for highly scalable, component-based applications that support concurrency and distribution. Programming Scala clearly explains the advantages of Scala as a JVM language. You'll learn how to leverage the wealth of Java class libraries to meet the practical needs of enterprise and Internet projects more easily. Packed with code examples, this book provides us

Grassmann Averages for Scalable Robust PCA

DEFF Research Database (Denmark)

Hauberg, Søren; Feragen, Aasa; Black, Michael J.

2014-01-01

As the collection of large datasets becomes increasingly automated, the occurrence of outliers will increase—“big data” implies “big outliers”. While principal component analysis (PCA) is often used to reduce the size of data, and scalable solutions exist, it is well-known that outliers can...... to vectors (subspaces) or elements of vectors; we focus on the latter and use a trimmed average. The resulting Trimmed Grassmann Average (TGA) is particularly appropriate for computer vision because it is robust to pixel outliers. The algorithm has low computational complexity and minimal memory requirements...

Domain decomposition method of stochastic PDEs: a two-level scalable preconditioner

International Nuclear Information System (INIS)

Subber, Waad; Sarkar, Abhijit

2012-01-01

For uncertainty quantification in many practical engineering problems, the stochastic finite element method (SFEM) may be computationally challenging. In SFEM, the size of the algebraic linear system grows rapidly with the spatial mesh resolution and the order of the stochastic dimension. In this paper, we describe a non-overlapping domain decomposition method, namely the iterative substructuring method to tackle the large-scale linear system arising in the SFEM. The SFEM is based on domain decomposition in the geometric space and a polynomial chaos expansion in the probabilistic space. In particular, a two-level scalable preconditioner is proposed for the iterative solver of the interface problem for the stochastic systems. The preconditioner is equipped with a coarse problem which globally connects the subdomains both in the geometric and probabilistic spaces via their corner nodes. This coarse problem propagates the information quickly across the subdomains leading to a scalable preconditioner. For numerical illustrations, a two-dimensional stochastic elliptic partial differential equation (SPDE) with spatially varying non-Gaussian random coefficients is considered. The numerical scalability of the the preconditioner is investigated with respect to the mesh size, subdomain size, fixed problem size per subdomain and order of polynomial chaos expansion. The numerical experiments are performed on a Linux cluster using MPI and PETSc parallel libraries.

NASA Thesaurus

Data.gov (United States)

National Aeronautics and Space Administration — The NASA Thesaurus contains the authorized NASA subject terms used to index and retrieve materials in the NASA Technical Reports Server (NTRS) and the NTRS...

Embedded DCT and wavelet methods for fine granular scalable video: analysis and comparison

Science.gov (United States)

van der Schaar-Mitrea, Mihaela; Chen, Yingwei; Radha, Hayder

2000-04-01

Video transmission over bandwidth-varying networks is becoming increasingly important due to emerging applications such as streaming of video over the Internet. The fundamental obstacle in designing such systems resides in the varying characteristics of the Internet (i.e. bandwidth variations and packet-loss patterns). In MPEG-4, a new SNR scalability scheme, called Fine-Granular-Scalability (FGS), is currently under standardization, which is able to adapt in real-time (i.e. at transmission time) to Internet bandwidth variations. The FGS framework consists of a non-scalable motion-predicted base-layer and an intra-coded fine-granular scalable enhancement layer. For example, the base layer can be coded using a DCT-based MPEG-4 compliant, highly efficient video compression scheme. Subsequently, the difference between the original and decoded base-layer is computed, and the resulting FGS-residual signal is intra-frame coded with an embedded scalable coder. In order to achieve high coding efficiency when compressing the FGS enhancement layer, it is crucial to analyze the nature and characteristics of residual signals common to the SNR scalability framework (including FGS). In this paper, we present a thorough analysis of SNR residual signals by evaluating its statistical properties, compaction efficiency and frequency characteristics. The signal analysis revealed that the energy compaction of the DCT and wavelet transforms is limited and the frequency characteristic of SNR residual signals decay rather slowly. Moreover, the blockiness artifacts of the low bit-rate coded base-layer result in artificial high frequencies in the residual signal. Subsequently, a variety of wavelet and embedded DCT coding techniques applicable to the FGS framework are evaluated and their results are interpreted based on the identified signal properties. As expected from the theoretical signal analysis, the rate-distortion performances of the embedded wavelet and DCT-based coders are very

Scalability and efficiency of genetic algorithms for geometrical applications

NARCIS (Netherlands)

Dijk, van S.F.; Thierens, D.; Berg, de M.; Schoenauer, M.

2000-01-01

We study the scalability and efficiency of a GA that we developed earlier to solve the practical cartographic problem of labeling a map with point features. We argue that the special characteristics of our GA make that it fits in well with theoretical models predicting the optimal population size

Estimates of the Sampling Distribution of Scalability Coefficient H

Science.gov (United States)

Van Onna, Marieke J. H.

2004-01-01

Coefficient "H" is used as an index of scalability in nonparametric item response theory (NIRT). It indicates the degree to which a set of items rank orders examinees. Theoretical sampling distributions, however, have only been derived asymptotically and only under restrictive conditions. Bootstrap methods offer an alternative possibility to…

LoRa Scalability: A Simulation Model Based on Interference Measurements.

Science.gov (United States)

Haxhibeqiri, Jetmir; Van den Abeele, Floris; Moerman, Ingrid; Hoebeke, Jeroen

2017-05-23

LoRa is a long-range, low power, low bit rate and single-hop wireless communication technology. It is intended to be used in Internet of Things (IoT) applications involving battery-powered devices with low throughput requirements. A LoRaWAN network consists of multiple end nodes that communicate with one or more gateways. These gateways act like a transparent bridge towards a common network server. The amount of end devices and their throughput requirements will have an impact on the performance of the LoRaWAN network. This study investigates the scalability in terms of the number of end devices per gateway of single-gateway LoRaWAN deployments. First, we determine the intra-technology interference behavior with two physical end nodes, by checking the impact of an interfering node on a transmitting node. Measurements show that even under concurrent transmission, one of the packets can be received under certain conditions. Based on these measurements, we create a simulation model for assessing the scalability of a single gateway LoRaWAN network. We show that when the number of nodes increases up to 1000 per gateway, the losses will be up to 32%. In such a case, pure Aloha will have around 90% losses. However, when the duty cycle of the application layer becomes lower than the allowed radio duty cycle of 1%, losses will be even lower. We also show network scalability simulation results for some IoT use cases based on real data.

Event metadata records as a testbed for scalable data mining

International Nuclear Information System (INIS)

Gemmeren, P van; Malon, D

2010-01-01

At a data rate of 200 hertz, event metadata records ('TAGs,' in ATLAS parlance) provide fertile grounds for development and evaluation of tools for scalable data mining. It is easy, of course, to apply HEP-specific selection or classification rules to event records and to label such an exercise 'data mining,' but our interest is different. Advanced statistical methods and tools such as classification, association rule mining, and cluster analysis are common outside the high energy physics community. These tools can prove useful, not for discovery physics, but for learning about our data, our detector, and our software. A fixed and relatively simple schema makes TAG export to other storage technologies such as HDF5 straightforward. This simplifies the task of exploiting very-large-scale parallel platforms such as Argonne National Laboratory's BlueGene/P, currently the largest supercomputer in the world for open science, in the development of scalable tools for data mining. Using a domain-neutral scientific data format may also enable us to take advantage of existing data mining components from other communities. There is, further, a substantial literature on the topic of one-pass algorithms and stream mining techniques, and such tools may be inserted naturally at various points in the event data processing and distribution chain. This paper describes early experience with event metadata records from ATLAS simulation and commissioning as a testbed for scalable data mining tool development and evaluation.

Scalable Light Module for Low-Cost, High-Efficiency Light- Emitting Diode Luminaires

Energy Technology Data Exchange (ETDEWEB)

Tarsa, Eric [Cree, Inc., Goleta, CA (United States)

2015-08-31

During this two-year program Cree developed a scalable, modular optical architecture for low-cost, high-efficacy light emitting diode (LED) luminaires. Stated simply, the goal of this architecture was to efficiently and cost-effectively convey light from LEDs (point sources) to broad luminaire surfaces (area sources). By simultaneously developing warm-white LED components and low-cost, scalable optical elements, a high system optical efficiency resulted. To meet program goals, Cree evaluated novel approaches to improve LED component efficacy at high color quality while not sacrificing LED optical efficiency relative to conventional packages. Meanwhile, efficiently coupling light from LEDs into modular optical elements, followed by optimally distributing and extracting this light, were challenges that were addressed via novel optical design coupled with frequent experimental evaluations. Minimizing luminaire bill of materials and assembly costs were two guiding principles for all design work, in the effort to achieve luminaires with significantly lower normalized cost ($/klm) than existing LED fixtures. Chief project accomplishments included the achievement of >150 lm/W warm-white LEDs having primary optics compatible with low-cost modular optical elements. In addition, a prototype Light Module optical efficiency of over 90% was measured, demonstrating the potential of this scalable architecture for ultra-high-efficacy LED luminaires. Since the project ended, Cree has continued to evaluate optical element fabrication and assembly methods in an effort to rapidly transfer this scalable, cost-effective technology to Cree production development groups. The Light Module concept is likely to make a strong contribution to the development of new cost-effective, high-efficacy luminaries, thereby accelerating widespread adoption of energy-saving SSL in the U.S.

Scalable force directed graph layout algorithms using fast multipole methods

KAUST Repository

Yunis, Enas Abdulrahman; Yokota, Rio; Ahmadia, Aron

2012-01-01

We present an extension to ExaFMM, a Fast Multipole Method library, as a generalized approach for fast and scalable execution of the Force-Directed Graph Layout algorithm. The Force-Directed Graph Layout algorithm is a physics-based approach

ESVD: An Integrated Energy Scalable Framework for Low-Power Video Decoding Systems

Directory of Open Access Journals (Sweden)

Wen Ji

2010-01-01

Full Text Available Video applications using mobile wireless devices are a challenging task due to the limited capacity of batteries. The higher complex functionality of video decoding needs high resource requirements. Thus, power efficient control has become more critical design with devices integrating complex video processing techniques. Previous works on power efficient control in video decoding systems often aim at the low complexity design and not explicitly consider the scalable impact of subfunctions in decoding process, and seldom consider the relationship with the features of compressed video date. This paper is dedicated to developing an energy-scalable video decoding (ESVD strategy for energy-limited mobile terminals. First, ESVE can dynamically adapt the variable energy resources due to the device aware technique. Second, ESVD combines the decoder control with decoded data, through classifying the data into different partition profiles according to its characteristics. Third, it introduces utility theoretical analysis during the resource allocation process, so as to maximize the resource utilization. Finally, it adapts the energy resource as different energy budget and generates the scalable video decoding output under energy-limited systems. Experimental results demonstrate the efficiency of the proposed approach.

Ultracold molecules: vehicles to scalable quantum information processing

International Nuclear Information System (INIS)

Brickman Soderberg, Kathy-Anne; Gemelke, Nathan; Chin Cheng

2009-01-01

In this paper, we describe a novel scheme to implement scalable quantum information processing using Li-Cs molecular states to entangle 6 Li and 133 Cs ultracold atoms held in independent optical lattices. The 6 Li atoms will act as quantum bits to store information and 133 Cs atoms will serve as messenger bits that aid in quantum gate operations and mediate entanglement between distant qubit atoms. Each atomic species is held in a separate optical lattice and the atoms can be overlapped by translating the lattices with respect to each other. When the messenger and qubit atoms are overlapped, targeted single-spin operations and entangling operations can be performed by coupling the atomic states to a molecular state with radio-frequency pulses. By controlling the frequency and duration of the radio-frequency pulses, entanglement can be either created or swapped between a qubit messenger pair. We estimate operation fidelities for entangling two distant qubits and discuss scalability of this scheme and constraints on the optical lattice lasers. Finally we demonstrate experimental control of the optical potentials sufficient to translate atoms in the lattice.

Silicon nanophotonics for scalable quantum coherent feedback networks

International Nuclear Information System (INIS)

Sarovar, Mohan; Brif, Constantin; Soh, Daniel B.S.; Cox, Jonathan; DeRose, Christopher T.; Camacho, Ryan; Davids, Paul

2016-01-01

The emergence of coherent quantum feedback control (CQFC) as a new paradigm for precise manipulation of dynamics of complex quantum systems has led to the development of efficient theoretical modeling and simulation tools and opened avenues for new practical implementations. This work explores the applicability of the integrated silicon photonics platform for implementing scalable CQFC networks. If proven successful, on-chip implementations of these networks would provide scalable and efficient nanophotonic components for autonomous quantum information processing devices and ultra-low-power optical processing systems at telecommunications wavelengths. We analyze the strengths of the silicon photonics platform for CQFC applications and identify the key challenges to both the theoretical formalism and experimental implementations. In particular, we determine specific extensions to the theoretical CQFC framework (which was originally developed with bulk-optics implementations in mind), required to make it fully applicable to modeling of linear and nonlinear integrated optics networks. We also report the results of a preliminary experiment that studied the performance of an in situ controllable silicon nanophotonic network of two coupled cavities and analyze the properties of this device using the CQFC formalism. (orig.)

Silicon nanophotonics for scalable quantum coherent feedback networks

Energy Technology Data Exchange (ETDEWEB)

Sarovar, Mohan; Brif, Constantin [Sandia National Laboratories, Livermore, CA (United States); Soh, Daniel B.S. [Sandia National Laboratories, Livermore, CA (United States); Stanford University, Edward L. Ginzton Laboratory, Stanford, CA (United States); Cox, Jonathan; DeRose, Christopher T.; Camacho, Ryan; Davids, Paul [Sandia National Laboratories, Albuquerque, NM (United States)

2016-12-15

The emergence of coherent quantum feedback control (CQFC) as a new paradigm for precise manipulation of dynamics of complex quantum systems has led to the development of efficient theoretical modeling and simulation tools and opened avenues for new practical implementations. This work explores the applicability of the integrated silicon photonics platform for implementing scalable CQFC networks. If proven successful, on-chip implementations of these networks would provide scalable and efficient nanophotonic components for autonomous quantum information processing devices and ultra-low-power optical processing systems at telecommunications wavelengths. We analyze the strengths of the silicon photonics platform for CQFC applications and identify the key challenges to both the theoretical formalism and experimental implementations. In particular, we determine specific extensions to the theoretical CQFC framework (which was originally developed with bulk-optics implementations in mind), required to make it fully applicable to modeling of linear and nonlinear integrated optics networks. We also report the results of a preliminary experiment that studied the performance of an in situ controllable silicon nanophotonic network of two coupled cavities and analyze the properties of this device using the CQFC formalism. (orig.)

New Region-Scalable Discriminant and Fitting Energy Functional for Driving Geometric Active Contours in Medical Image Segmentation

Directory of Open Access Journals (Sweden)

Xuchu Wang

2014-01-01

that uses region-scalable discriminant and fitting energy functional for handling the intensity inhomogeneity and weak boundary problems in medical image segmentation. The region-scalable discriminant and fitting energy functional is defined to capture the image intensity characteristics in local and global regions for driving the evolution of active contour. The discriminant term in the model aims at separating background and foreground in scalable regions while the fitting term tends to fit the intensity in these regions. This model is then transformed into a variational level set formulation with a level set regularization term for accurate computation. The new model utilizes intensity information in the local and global regions as much as possible; so it not only handles better intensity inhomogeneity, but also allows more robustness to noise and more flexible initialization in comparison to the original global region and regional-scalable based models. Experimental results for synthetic and real medical image segmentation show the advantages of the proposed method in terms of accuracy and robustness.

Scalable Tensor Factorizations with Missing Data

DEFF Research Database (Denmark)

Acar, Evrim; Dunlavy, Daniel M.; Kolda, Tamara G.

2010-01-01

of missing data, many important data sets will be discarded or improperly analyzed. Therefore, we need a robust and scalable approach for factorizing multi-way arrays (i.e., tensors) in the presence of missing data. We focus on one of the most well-known tensor factorizations, CANDECOMP/PARAFAC (CP...... is shown to successfully factor tensors with noise and up to 70% missing data. Moreover, our approach is significantly faster than the leading alternative and scales to larger problems. To show the real-world usefulness of CP-WOPT, we illustrate its applicability on a novel EEG (electroencephalogram...

Tip-Based Nanofabrication for Scalable Manufacturing

Directory of Open Access Journals (Sweden)

Huan Hu

2017-03-01

Full Text Available Tip-based nanofabrication (TBN is a family of emerging nanofabrication techniques that use a nanometer scale tip to fabricate nanostructures. In this review, we first introduce the history of the TBN and the technology development. We then briefly review various TBN techniques that use different physical or chemical mechanisms to fabricate features and discuss some of the state-of-the-art techniques. Subsequently, we focus on those TBN methods that have demonstrated potential to scale up the manufacturing throughput. Finally, we discuss several research directions that are essential for making TBN a scalable nano-manufacturing technology.

Tip-Based Nanofabrication for Scalable Manufacturing

International Nuclear Information System (INIS)

Hu, Huan; Somnath, Suhas

2017-01-01

Tip-based nanofabrication (TBN) is a family of emerging nanofabrication techniques that use a nanometer scale tip to fabricate nanostructures. Here in this review, we first introduce the history of the TBN and the technology development. We then briefly review various TBN techniques that use different physical or chemical mechanisms to fabricate features and discuss some of the state-of-the-art techniques. Subsequently, we focus on those TBN methods that have demonstrated potential to scale up the manufacturing throughput. Finally, we discuss several research directions that are essential for making TBN a scalable nano-manufacturing technology.

Semantic Models for Scalable Search in the Internet of Things

Directory of Open Access Journals (Sweden)

Dennis Pfisterer

2013-03-01

Full Text Available The Internet of Things is anticipated to connect billions of embedded devices equipped with sensors to perceive their surroundings. Thereby, the state of the real world will be available online and in real-time and can be combined with other data and services in the Internet to realize novel applications such as Smart Cities, Smart Grids, or Smart Healthcare. This requires an open representation of sensor data and scalable search over data from diverse sources including sensors. In this paper we show how the Semantic Web technologies RDF (an open semantic data format and SPARQL (a query language for RDF-encoded data can be used to address those challenges. In particular, we describe how prediction models can be employed for scalable sensor search, how these prediction models can be encoded as RDF, and how the models can be queried by means of SPARQL.

NASA Astrophysics Technology Needs

Science.gov (United States)

Stahl, H. Philip

2012-01-01

July 2010, NASA Office of Chief Technologist (OCT) initiated an activity to create and maintain a NASA integrated roadmap for 15 key technology areas which recommend an overall technology investment strategy and prioritize NASA?s technology programs to meet NASA?s strategic goals. Science Instruments, Observatories and Sensor Systems(SIOSS) roadmap addresses technology needs to achieve NASA?s highest priority objectives -- not only for the Science Mission Directorate (SMD), but for all of NASA.

LoRa Scalability: A Simulation Model Based on Interference Measurements

Directory of Open Access Journals (Sweden)

Jetmir Haxhibeqiri

2017-05-01

Full Text Available LoRa is a long-range, low power, low bit rate and single-hop wireless communication technology. It is intended to be used in Internet of Things (IoT applications involving battery-powered devices with low throughput requirements. A LoRaWAN network consists of multiple end nodes that communicate with one or more gateways. These gateways act like a transparent bridge towards a common network server. The amount of end devices and their throughput requirements will have an impact on the performance of the LoRaWAN network. This study investigates the scalability in terms of the number of end devices per gateway of single-gateway LoRaWAN deployments. First, we determine the intra-technology interference behavior with two physical end nodes, by checking the impact of an interfering node on a transmitting node. Measurements show that even under concurrent transmission, one of the packets can be received under certain conditions. Based on these measurements, we create a simulation model for assessing the scalability of a single gateway LoRaWAN network. We show that when the number of nodes increases up to 1000 per gateway, the losses will be up to 32%. In such a case, pure Aloha will have around 90% losses. However, when the duty cycle of the application layer becomes lower than the allowed radio duty cycle of 1%, losses will be even lower. We also show network scalability simulation results for some IoT use cases based on real data.

Scalable quality assurance for large SNOMED CT hierarchies using subject-based subtaxonomies.

Science.gov (United States)

Ochs, Christopher; Geller, James; Perl, Yehoshua; Chen, Yan; Xu, Junchuan; Min, Hua; Case, James T; Wei, Zhi

2015-05-01

Standards terminologies may be large and complex, making their quality assurance challenging. Some terminology quality assurance (TQA) methodologies are based on abstraction networks (AbNs), compact terminology summaries. We have tested AbNs and the performance of related TQA methodologies on small terminology hierarchies. However, some standards terminologies, for example, SNOMED, are composed of very large hierarchies. Scaling AbN TQA techniques to such hierarchies poses a significant challenge. We present a scalable subject-based approach for AbN TQA. An innovative technique is presented for scaling TQA by creating a new kind of subject-based AbN called a subtaxonomy for large hierarchies. New hypotheses about concentrations of erroneous concepts within the AbN are introduced to guide scalable TQA. We test the TQA methodology for a subject-based subtaxonomy for the Bleeding subhierarchy in SNOMED's large Clinical finding hierarchy. To test the error concentration hypotheses, three domain experts reviewed a sample of 300 concepts. A consensus-based evaluation identified 87 erroneous concepts. The subtaxonomy-based TQA methodology was shown to uncover statistically significantly more erroneous concepts when compared to a control sample. The scalability of TQA methodologies is a challenge for large standards systems like SNOMED. We demonstrated innovative subject-based TQA techniques by identifying groups of concepts with a higher likelihood of having errors within the subtaxonomy. Scalability is achieved by reviewing a large hierarchy by subject. An innovative methodology for scaling the derivation of AbNs and a TQA methodology was shown to perform successfully for the largest hierarchy of SNOMED. © The Author 2014. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

SRC: FenixOS - A Research Operating System Focused on High Scalability and Reliability

DEFF Research Database (Denmark)

Passas, Stavros; Karlsson, Sven

2011-01-01

Computer systems keep increasing in size. Systems scale in the number of processing units, memories and peripheral devices. This creates many and diverse architectural trade-offs that the existing operating systems are not able to address. We are designing and implementing, FenixOS, a new operating...... of the operating system....... system that aims to improve the state of the art in scalability and reliability. We achieve scalability through limiting data sharing when possible, and through extensive use of lock-free data structures. Reliability is addressed with a careful re-design of the programming interface and structure...

A Scalable Data Access Layer to Manage Structured Heterogeneous Biomedical Data.

Directory of Open Access Journals (Sweden)

Giovanni Delussu

Full Text Available This work presents a scalable data access layer, called PyEHR, designed to support the implementation of data management systems for secondary use of structured heterogeneous biomedical and clinical data. PyEHR adopts the openEHR's formalisms to guarantee the decoupling of data descriptions from implementation details and exploits structure indexing to accelerate searches. Data persistence is guaranteed by a driver layer with a common driver interface. Interfaces for two NoSQL Database Management Systems are already implemented: MongoDB and Elasticsearch. We evaluated the scalability of PyEHR experimentally through two types of tests, called "Constant Load" and "Constant Number of Records", with queries of increasing complexity on synthetic datasets of ten million records each, containing very complex openEHR archetype structures, distributed on up to ten computing nodes.

A Scalable Data Access Layer to Manage Structured Heterogeneous Biomedical Data

Science.gov (United States)

Lianas, Luca; Frexia, Francesca; Zanetti, Gianluigi

2016-01-01

This work presents a scalable data access layer, called PyEHR, designed to support the implementation of data management systems for secondary use of structured heterogeneous biomedical and clinical data. PyEHR adopts the openEHR’s formalisms to guarantee the decoupling of data descriptions from implementation details and exploits structure indexing to accelerate searches. Data persistence is guaranteed by a driver layer with a common driver interface. Interfaces for two NoSQL Database Management Systems are already implemented: MongoDB and Elasticsearch. We evaluated the scalability of PyEHR experimentally through two types of tests, called “Constant Load” and “Constant Number of Records”, with queries of increasing complexity on synthetic datasets of ten million records each, containing very complex openEHR archetype structures, distributed on up to ten computing nodes. PMID:27936191

A Scalable Data Access Layer to Manage Structured Heterogeneous Biomedical Data.

Science.gov (United States)

Delussu, Giovanni; Lianas, Luca; Frexia, Francesca; Zanetti, Gianluigi

2016-01-01

This work presents a scalable data access layer, called PyEHR, designed to support the implementation of data management systems for secondary use of structured heterogeneous biomedical and clinical data. PyEHR adopts the openEHR's formalisms to guarantee the decoupling of data descriptions from implementation details and exploits structure indexing to accelerate searches. Data persistence is guaranteed by a driver layer with a common driver interface. Interfaces for two NoSQL Database Management Systems are already implemented: MongoDB and Elasticsearch. We evaluated the scalability of PyEHR experimentally through two types of tests, called "Constant Load" and "Constant Number of Records", with queries of increasing complexity on synthetic datasets of ten million records each, containing very complex openEHR archetype structures, distributed on up to ten computing nodes.

Containment Domains: A Scalable, Efficient and Flexible Resilience Scheme for Exascale Systems

Directory of Open Access Journals (Sweden)

Jinsuk Chung

2013-01-01

Full Text Available This paper describes and evaluates a scalable and efficient resilience scheme based on the concept of containment domains. Containment domains are a programming construct that enable applications to express resilience needs and to interact with the system to tune and specialize error detection, state preservation and restoration, and recovery schemes. Containment domains have weak transactional semantics and are nested to take advantage of the machine and application hierarchies and to enable hierarchical state preservation, restoration and recovery. We evaluate the scalability and efficiency of containment domains using generalized trace-driven simulation and analytical analysis and show that containment domains are superior to both checkpoint restart and redundant execution approaches.

Scalable Metadata Management for a Large Multi-Source Seismic Data Repository

Energy Technology Data Exchange (ETDEWEB)

Gaylord, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dodge, D. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Magana-Zook, S. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Barno, J. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Knapp, D. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thomas, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sullivan, D. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ruppert, S. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mellors, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-05-26

In this work, we implemented the key metadata management components of a scalable seismic data ingestion framework to address limitations in our existing system, and to position it for anticipated growth in volume and complexity.

Emerging Cyber Infrastructure for NASA's Large-Scale Climate Data Analytics

Science.gov (United States)

Duffy, D.; Spear, C.; Bowen, M. K.; Thompson, J. H.; Hu, F.; Yang, C. P.; Pierce, D.

2016-12-01

The resolution of NASA climate and weather simulations have grown dramatically over the past few years with the highest-fidelity models reaching down to 1.5 KM global resolutions. With each doubling of the resolution, the resulting data sets grow by a factor of eight in size. As the climate and weather models push the envelope even further, a new infrastructure to store data and provide large-scale data analytics is necessary. The NASA Center for Climate Simulation (NCCS) has deployed the Data Analytics Storage Service (DASS) that combines scalable storage with the ability to perform in-situ analytics. Within this system, large, commonly used data sets are stored in a POSIX file system (write once/read many); examples of data stored include Landsat, MERRA2, observing system simulation experiments, and high-resolution downscaled reanalysis. The total size of this repository is on the order of 15 petabytes of storage. In addition to the POSIX file system, the NCCS has deployed file system connectors to enable emerging analytics built on top of the Hadoop File System (HDFS) to run on the same storage servers within the DASS. Coupled with a custom spatiotemporal indexing approach, users can now run emerging analytical operations built on MapReduce and Spark on the same data files stored within the POSIX file system without having to make additional copies. This presentation will discuss the architecture of this system and present benchmark performance measurements from traditional TeraSort and Wordcount to large-scale climate analytical operations on NetCDF data.

A Numerical Study of Scalable Cardiac Electro-Mechanical Solvers on HPC Architectures

Directory of Open Access Journals (Sweden)

Piero Colli Franzone

2018-04-01

Full Text Available We introduce and study some scalable domain decomposition preconditioners for cardiac electro-mechanical 3D simulations on parallel HPC (High Performance Computing architectures. The electro-mechanical model of the cardiac tissue is composed of four coupled sub-models: (1 the static finite elasticity equations for the transversely isotropic deformation of the cardiac tissue; (2 the active tension model describing the dynamics of the intracellular calcium, cross-bridge binding and myofilament tension; (3 the anisotropic Bidomain model describing the evolution of the intra- and extra-cellular potentials in the deforming cardiac tissue; and (4 the ionic membrane model describing the dynamics of ionic currents, gating variables, ionic concentrations and stretch-activated channels. This strongly coupled electro-mechanical model is discretized in time with a splitting semi-implicit technique and in space with isoparametric finite elements. The resulting scalable parallel solver is based on Multilevel Additive Schwarz preconditioners for the solution of the Bidomain system and on BDDC preconditioned Newton-Krylov solvers for the non-linear finite elasticity system. The results of several 3D parallel simulations show the scalability of both linear and non-linear solvers and their application to the study of both physiological excitation-contraction cardiac dynamics and re-entrant waves in the presence of different mechano-electrical feedbacks.

Hardware Implementation of Lossless Adaptive and Scalable Hyperspectral Data Compression for Space

Science.gov (United States)

Aranki, Nazeeh; Keymeulen, Didier; Bakhshi, Alireza; Klimesh, Matthew

2009-01-01

On-board lossless hyperspectral data compression reduces data volume in order to meet NASA and DoD limited downlink capabilities. The technique also improves signature extraction, object recognition and feature classification capabilities by providing exact reconstructed data on constrained downlink resources. At JPL a novel, adaptive and predictive technique for lossless compression of hyperspectral data was recently developed. This technique uses an adaptive filtering method and achieves a combination of low complexity and compression effectiveness that far exceeds state-of-the-art techniques currently in use. The JPL-developed 'Fast Lossless' algorithm requires no training data or other specific information about the nature of the spectral bands for a fixed instrument dynamic range. It is of low computational complexity and thus well-suited for implementation in hardware. A modified form of the algorithm that is better suited for data from pushbroom instruments is generally appropriate for flight implementation. A scalable field programmable gate array (FPGA) hardware implementation was developed. The FPGA implementation achieves a throughput performance of 58 Msamples/sec, which can be increased to over 100 Msamples/sec in a parallel implementation that uses twice the hardware resources This paper describes the hardware implementation of the 'Modified Fast Lossless' compression algorithm on an FPGA. The FPGA implementation targets the current state-of-the-art FPGAs (Xilinx Virtex IV and V families) and compresses one sample every clock cycle to provide a fast and practical real-time solution for space applications.

Using self-similarity compensation for improving inter-layer prediction in scalable 3D holoscopic video coding

Science.gov (United States)

Conti, Caroline; Nunes, Paulo; Ducla Soares, Luís.

2013-09-01

Holoscopic imaging, also known as integral imaging, has been recently attracting the attention of the research community, as a promising glassless 3D technology due to its ability to create a more realistic depth illusion than the current stereoscopic or multiview solutions. However, in order to gradually introduce this technology into the consumer market and to efficiently deliver 3D holoscopic content to end-users, backward compatibility with legacy displays is essential. Consequently, to enable 3D holoscopic content to be delivered and presented on legacy displays, a display scalable 3D holoscopic coding approach is required. Hence, this paper presents a display scalable architecture for 3D holoscopic video coding with a three-layer approach, where each layer represents a different level of display scalability: Layer 0 - a single 2D view; Layer 1 - 3D stereo or multiview; and Layer 2 - the full 3D holoscopic content. In this context, a prediction method is proposed, which combines inter-layer prediction, aiming to exploit the existing redundancy between the multiview and the 3D holoscopic layers, with self-similarity compensated prediction (previously proposed by the authors for non-scalable 3D holoscopic video coding), aiming to exploit the spatial redundancy inherent to the 3D holoscopic enhancement layer. Experimental results show that the proposed combined prediction can improve significantly the rate-distortion performance of scalable 3D holoscopic video coding with respect to the authors' previously proposed solutions, where only inter-layer or only self-similarity prediction is used.

NASA strategic plan

Science.gov (United States)

1994-01-01

The NASA Strategic Plan is a living document. It provides far-reaching goals and objectives to create stability for NASA's efforts. The Plan presents NASA's top-level strategy: it articulates what NASA does and for whom; it differentiates between ends and means; it states where NASA is going and what NASA intends to do to get there. This Plan is not a budget document, nor does it present priorities for current or future programs. Rather, it establishes a framework for shaping NASA's activities and developing a balanced set of priorities across the Agency. Such priorities will then be reflected in the NASA budget. The document includes vision, mission, and goals; external environment; conceptual framework; strategic enterprises (Mission to Planet Earth, aeronautics, human exploration and development of space, scientific research, space technology, and synergy); strategic functions (transportation to space, space communications, human resources, and physical resources); values and operating principles; implementing strategy; and senior management team concurrence.

Scalable fast multipole methods for vortex element methods

KAUST Repository

Hu, Qi

2012-11-01

We use a particle-based method to simulate incompressible flows, where the Fast Multipole Method (FMM) is used to accelerate the calculation of particle interactions. The most time-consuming kernelsâ\\'the Biot-Savart equation and stretching term of the vorticity equationâ\\'are mathematically reformulated so that only two Laplace scalar potentials are used instead of six, while automatically ensuring divergence-free far-field computation. Based on this formulation, and on our previous work for a scalar heterogeneous FMM algorithm, we develop a new FMM-based vortex method capable of simulating general flows including turbulence on heterogeneous architectures, which distributes the work between multi-core CPUs and GPUs to best utilize the hardware resources and achieve excellent scalability. The algorithm also uses new data structures which can dynamically manage inter-node communication and load balance efficiently but with only a small parallel construction overhead. This algorithm can scale to large-sized clusters showing both strong and weak scalability. Careful error and timing trade-off analysis are also performed for the cutoff functions induced by the vortex particle method. Our implementation can perform one time step of the velocity+stretching for one billion particles on 32 nodes in 55.9 seconds, which yields 49.12 Tflop/s. © 2012 IEEE.

Temporal Scalability of Dynamic Volume Data using Mesh Compensated Wavelet Lifting.

Science.gov (United States)

Schnurrer, Wolfgang; Pallast, Niklas; Richter, Thomas; Kaup, Andre

2017-10-12

Due to their high resolution, dynamic medical 2D+t and 3D+t volumes from computed tomography (CT) and magnetic resonance tomography (MR) reach a size which makes them very unhandy for teleradiologic applications. A lossless scalable representation offers the advantage of a down-scaled version which can be used for orientation or previewing, while the remaining information for reconstructing the full resolution is transmitted on demand. The wavelet transform offers the desired scalability. A very high quality of the lowpass sub-band is crucial in order to use it as a down-scaled representation. We propose an approach based on compensated wavelet lifting for obtaining a scalable representation of dynamic CT and MR volumes with very high quality. The mesh compensation is feasible to model the displacement in dynamic volumes which is mainly given by expansion and contraction of tissue over time. To achieve this, we propose an optimized estimation of the mesh compensation parameters to optimally fit for dynamic volumes. Within the lifting structure, the inversion of the motion compensation is crucial in the update step. We propose to take this inversion directly into account during the estimation step and can improve the quality of the lowpass sub-band by 0.63 dB and 0.43 dB on average for our tested dynamic CT and MR volumes at the cost of an increase of the rate by 2.4% and 1.2% on average.

Sustainability and scalability of a volunteer-based primary care intervention (Health TAPESTRY): a mixed-methods analysis.

Science.gov (United States)

Kastner, Monika; Sayal, Radha; Oliver, Doug; Straus, Sharon E; Dolovich, Lisa

2017-08-01

Chronic diseases are a significant public health concern, particularly in older adults. To address the delivery of health care services to optimally meet the needs of older adults with multiple chronic diseases, Health TAPESTRY (Teams Advancing Patient Experience: Strengthening Quality) uses a novel approach that involves patient home visits by trained volunteers to collect and transmit relevant health information using e-health technology to inform appropriate care from an inter-professional healthcare team. Health TAPESTRY was implemented, pilot tested, and evaluated in a randomized controlled trial (analysis underway). Knowledge translation (KT) interventions such as Health TAPESTRY should involve an investigation of their sustainability and scalability determinants to inform further implementation. However, this is seldom considered in research or considered early enough, so the objectives of this study were to assess the sustainability and scalability potential of Health TAPESTRY from the perspective of the team who developed and pilot-tested it. Our objectives were addressed using a sequential mixed-methods approach involving the administration of a validated, sustainability survey developed by the National Health Service (NHS) to all members of the Health TAPESTRY team who were actively involved in the development, implementation and pilot evaluation of the intervention (Phase 1: n = 38). Mean sustainability scores were calculated to identify the best potential for improvement across sustainability factors. Phase 2 was a qualitative study of interviews with purposively selected Health TAPESTRY team members to gain a more in-depth understanding of the factors that influence the sustainability and scalability Health TAPESTRY. Two independent reviewers coded transcribed interviews and completed a multi-step thematic analysis. Outcomes were participant perceptions of the determinants influencing the sustainability and scalability of Health TAPESTRY. Twenty

Computational scalability of large size image dissemination

Science.gov (United States)

Kooper, Rob; Bajcsy, Peter

2011-01-01

We have investigated the computational scalability of image pyramid building needed for dissemination of very large image data. The sources of large images include high resolution microscopes and telescopes, remote sensing and airborne imaging, and high resolution scanners. The term 'large' is understood from a user perspective which means either larger than a display size or larger than a memory/disk to hold the image data. The application drivers for our work are digitization projects such as the Lincoln Papers project (each image scan is about 100-150MB or about 5000x8000 pixels with the total number to be around 200,000) and the UIUC library scanning project for historical maps from 17th and 18th century (smaller number but larger images). The goal of our work is understand computational scalability of the web-based dissemination using image pyramids for these large image scans, as well as the preservation aspects of the data. We report our computational benchmarks for (a) building image pyramids to be disseminated using the Microsoft Seadragon library, (b) a computation execution approach using hyper-threading to generate image pyramids and to utilize the underlying hardware, and (c) an image pyramid preservation approach using various hard drive configurations of Redundant Array of Independent Disks (RAID) drives for input/output operations. The benchmarks are obtained with a map (334.61 MB, JPEG format, 17591x15014 pixels). The discussion combines the speed and preservation objectives.

Blind Cooperative Routing for Scalable and Energy-Efficient Internet of Things

KAUST Repository

Bader, Ahmed

2016-02-26

Multihop networking is promoted in this paper for energy-efficient and highly-scalable Internet of Things (IoT). Recognizing concerns related to the scalability of classical multihop routing and medium access techniques, the use of blind cooperation in conjunction with multihop communications is advocated herewith. Blind cooperation however is actually shown to be inefficient unless power control is applied. Inefficiency in this paper is projected in terms of the transport rate normalized to energy consumption. To that end, an uncoordinated power control mechanism is proposed whereby each device in a blind cooperative cluster randomly adjusts its transmit power level. An upper bound is derived for the mean transmit power that must be observed at each device. Finally, the uncoordinated power control mechanism is demonstrated to consistently outperform the simple point-to-point routing case. © 2015 IEEE.

VPLS: an effective technology for building scalable transparent LAN services

Science.gov (United States)

Dong, Ximing; Yu, Shaohua

2005-02-01

Virtual Private LAN Service (VPLS) is generating considerable interest with enterprises and service providers as it offers multipoint transparent LAN service (TLS) over MPLS networks. This paper describes an effective technology - VPLS, which links virtual switch instances (VSIs) through MPLS to form an emulated Ethernet switch and build Scalable Transparent Lan Services. It first focuses on the architecture of VPLS with Ethernet bridging technique at the edge and MPLS at the core, then it tries to elucidate the data forwarding mechanism within VPLS domain, including learning and aging MAC addresses on a per LSP basis, flooding of unknown frames and replication for unknown, multicast, and broadcast frames. The loop-avoidance mechanism, known as split horizon forwarding, is also analyzed. Another important aspect of VPLS service is its basic operation, including autodiscovery and signaling, is discussed. From the perspective of efficiency and scalability the paper compares two important signaling mechanism, BGP and LDP, which are used to set up a PW between the PEs and bind the PWs to a particular VSI. With the extension of VPLS and the increase of full mesh of PWs between PE devices (n*(n-1)/2 PWs in all, a n2 complete problem), VPLS instance could have a large number of remote PE associations, resulting in an inefficient use of network bandwidth and system resources as the ingress PE has to replicate each frame and append MPLS labels for remote PE. So the latter part of this paper focuses on the scalability issue: the Hierarchical VPLS. Within the architecture of HVPLS, this paper addresses two ways to cope with a possibly large number of MAC addresses, which make VPLS operate more efficiently.

Internal NASA Study: NASAs Protoflight Research Initiative

Science.gov (United States)

Coan, Mary R.; Hirshorn, Steven R.; Moreland, Robert

2015-01-01

The NASA Protoflight Research Initiative is an internal NASA study conducted within the Office of the Chief Engineer to better understand the use of Protoflight within NASA. Extensive literature reviews and interviews with key NASA members with experience in both robotic and human spaceflight missions has resulted in three main conclusions and two observations. The first conclusion is that NASA's Protoflight method is not considered to be "prescriptive." The current policies and guidance allows each Program/Project to tailor the Protoflight approach to better meet their needs, goals and objectives. Second, Risk Management plays a key role in implementation of the Protoflight approach. Any deviations from full qualification will be based on the level of acceptable risk with guidance found in NPR 8705.4. Finally, over the past decade (2004 - 2014) only 6% of NASA's Protoflight missions and 6% of NASA's Full qualification missions experienced a publicly disclosed mission failure. In other words, the data indicates that the Protoflight approach, in and of it itself, does not increase the mission risk of in-flight failure. The first observation is that it would be beneficial to document the decision making process on the implementation and use of Protoflight. The second observation is that If a Project/Program chooses to use the Protoflight approach with relevant heritage, it is extremely important that the Program/Project Manager ensures that the current project's requirements falls within the heritage design, component, instrument and/or subsystem's requirements for both the planned and operational use, and that the documentation of the relevant heritage is comprehensive, sufficient and the decision well documented. To further benefit/inform this study, a recommendation to perform a deep dive into 30 missions with accessible data on their testing/verification methodology and decision process to research the differences between Protoflight and Full Qualification

The NASA Severe Thunderstorm Observations and Regional Modeling (NASA STORM) Project

Science.gov (United States)

Schultz, Christopher J.; Gatlin, Patrick N.; Lang, Timothy J.; Srikishen, Jayanthi; Case, Jonathan L.; Molthan, Andrew L.; Zavodsky, Bradley T.; Bailey, Jeffrey; Blakeslee, Richard J.; Jedlovec, Gary J.

2016-01-01

The NASA Severe Storm Thunderstorm Observations and Regional Modeling(NASA STORM) project enhanced NASA’s severe weather research capabilities, building upon existing Earth Science expertise at NASA Marshall Space Flight Center (MSFC). During this project, MSFC extended NASA’s ground-based lightning detection capacity to include a readily deployable lightning mapping array (LMA). NASA STORM also enabled NASA’s Short-term Prediction and Research Transition (SPoRT) to add convection allowing ensemble modeling to its portfolio of regional numerical weather prediction (NWP) capabilities. As a part of NASA STORM, MSFC developed new open-source capabilities for analyzing and displaying weather radar observations integrated from both research and operational networks. These accomplishments enabled by NASA STORM are a step towards enhancing NASA’s capabilities for studying severe weather and positions them for any future NASA related severe storm field campaigns.

Status of NASA's Advanced Radioisotope Power Conversion Technology Research and Development

Science.gov (United States)

Wong, Wayne A.; Anderson, David J.; Tuttle, Karen L.; Tew, Roy C.

2006-01-01

NASA s Advanced Radioisotope Power Systems (RPS) development program is funding the advancement of next generation power conversion technologies that will enable future missions that have requirements that can not be met by either the ubiquitous photovoltaic systems or by current Radioisotope Power Systems (RPS). Requirements of advanced radioisotope power systems include high efficiency and high specific power (watts/kilogram) in order to meet mission requirements with less radioisotope fuel and lower mass. Other Advanced RPS development goals include long-life, reliability, and scalability so that these systems can meet requirements for a variety of future space applications including continual operation surface missions, outer-planetary missions, and solar probe. This paper provides an update on the Radioisotope Power Conversion Technology Project which awarded ten Phase I contracts for research and development of a variety of power conversion technologies consisting of Brayton, Stirling, thermoelectrics, and thermophotovoltaics. Three of the contracts continue during the current Phase II in the areas of thermoelectric and Stirling power conversion. The accomplishments to date of the contractors, project plans, and status will be summarized.

Scalable Adaptive Graphics Environment (SAGE) Software for the Visualization of Large Data Sets on a Video Wall

Science.gov (United States)

Jedlovec, Gary; Srikishen, Jayanthi; Edwards, Rita; Cross, David; Welch, Jon; Smith, Matt

2013-01-01

The use of collaborative scientific visualization systems for the analysis, visualization, and sharing of "big data" available from new high resolution remote sensing satellite sensors or four-dimensional numerical model simulations is propelling the wider adoption of ultra-resolution tiled display walls interconnected by high speed networks. These systems require a globally connected and well-integrated operating environment that provides persistent visualization and collaboration services. This abstract and subsequent presentation describes a new collaborative visualization system installed for NASA's Shortterm Prediction Research and Transition (SPoRT) program at Marshall Space Flight Center and its use for Earth science applications. The system consists of a 3 x 4 array of 1920 x 1080 pixel thin bezel video monitors mounted on a wall in a scientific collaboration lab. The monitors are physically and virtually integrated into a 14' x 7' for video display. The display of scientific data on the video wall is controlled by a single Alienware Aurora PC with a 2nd Generation Intel Core 4.1 GHz processor, 32 GB memory, and an AMD Fire Pro W600 video card with 6 mini display port connections. Six mini display-to-dual DVI cables are used to connect the 12 individual video monitors. The open source Scalable Adaptive Graphics Environment (SAGE) windowing and media control framework, running on top of the Ubuntu 12 Linux operating system, allows several users to simultaneously control the display and storage of high resolution still and moving graphics in a variety of formats, on tiled display walls of any size. The Ubuntu operating system supports the open source Scalable Adaptive Graphics Environment (SAGE) software which provides a common environment, or framework, enabling its users to access, display and share a variety of data-intensive information. This information can be digital-cinema animations, high-resolution images, high-definition video

Scalable Adaptive Graphics Environment (SAGE) Software for the Visualization of Large Data Sets on a Video Wall

Science.gov (United States)

Jedlovec, G.; Srikishen, J.; Edwards, R.; Cross, D.; Welch, J. D.; Smith, M. R.

2013-12-01

The use of collaborative scientific visualization systems for the analysis, visualization, and sharing of 'big data' available from new high resolution remote sensing satellite sensors or four-dimensional numerical model simulations is propelling the wider adoption of ultra-resolution tiled display walls interconnected by high speed networks. These systems require a globally connected and well-integrated operating environment that provides persistent visualization and collaboration services. This abstract and subsequent presentation describes a new collaborative visualization system installed for NASA's Short-term Prediction Research and Transition (SPoRT) program at Marshall Space Flight Center and its use for Earth science applications. The system consists of a 3 x 4 array of 1920 x 1080 pixel thin bezel video monitors mounted on a wall in a scientific collaboration lab. The monitors are physically and virtually integrated into a 14' x 7' for video display. The display of scientific data on the video wall is controlled by a single Alienware Aurora PC with a 2nd Generation Intel Core 4.1 GHz processor, 32 GB memory, and an AMD Fire Pro W600 video card with 6 mini display port connections. Six mini display-to-dual DVI cables are used to connect the 12 individual video monitors. The open source Scalable Adaptive Graphics Environment (SAGE) windowing and media control framework, running on top of the Ubuntu 12 Linux operating system, allows several users to simultaneously control the display and storage of high resolution still and moving graphics in a variety of formats, on tiled display walls of any size. The Ubuntu operating system supports the open source Scalable Adaptive Graphics Environment (SAGE) software which provides a common environment, or framework, enabling its users to access, display and share a variety of data-intensive information. This information can be digital-cinema animations, high-resolution images, high-definition video

Scalable graphene production: perspectives and challenges of plasma applications

Science.gov (United States)

Levchenko, Igor; Ostrikov, Kostya (Ken); Zheng, Jie; Li, Xingguo; Keidar, Michael; B. K. Teo, Kenneth

2016-05-01

Graphene, a newly discovered and extensively investigated material, has many unique and extraordinary properties which promise major technological advances in fields ranging from electronics to mechanical engineering and food production. Unfortunately, complex techniques and high production costs hinder commonplace applications. Scaling of existing graphene production techniques to the industrial level without compromising its properties is a current challenge. This article focuses on the perspectives and challenges of scalability, equipment, and technological perspectives of the plasma-based techniques which offer many unique possibilities for the synthesis of graphene and graphene-containing products. The plasma-based processes are amenable for scaling and could also be useful to enhance the controllability of the conventional chemical vapour deposition method and some other techniques, and to ensure a good quality of the produced graphene. We examine the unique features of the plasma-enhanced graphene production approaches, including the techniques based on inductively-coupled and arc discharges, in the context of their potential scaling to mass production following the generic scaling approaches applicable to the existing processes and systems. This work analyses a large amount of the recent literature on graphene production by various techniques and summarizes the results in a tabular form to provide a simple and convenient comparison of several available techniques. Our analysis reveals a significant potential of scalability for plasma-based technologies, based on the scaling-related process characteristics. Among other processes, a greater yield of 1 g × h-1 m-2 was reached for the arc discharge technology, whereas the other plasma-based techniques show process yields comparable to the neutral-gas based methods. Selected plasma-based techniques show lower energy consumption than in thermal CVD processes, and the ability to produce graphene flakes of various

Scalable graphene production: perspectives and challenges of plasma applications.

Science.gov (United States)

Levchenko, Igor; Ostrikov, Kostya Ken; Zheng, Jie; Li, Xingguo; Keidar, Michael; B K Teo, Kenneth

2016-05-19

Graphene, a newly discovered and extensively investigated material, has many unique and extraordinary properties which promise major technological advances in fields ranging from electronics to mechanical engineering and food production. Unfortunately, complex techniques and high production costs hinder commonplace applications. Scaling of existing graphene production techniques to the industrial level without compromising its properties is a current challenge. This article focuses on the perspectives and challenges of scalability, equipment, and technological perspectives of the plasma-based techniques which offer many unique possibilities for the synthesis of graphene and graphene-containing products. The plasma-based processes are amenable for scaling and could also be useful to enhance the controllability of the conventional chemical vapour deposition method and some other techniques, and to ensure a good quality of the produced graphene. We examine the unique features of the plasma-enhanced graphene production approaches, including the techniques based on inductively-coupled and arc discharges, in the context of their potential scaling to mass production following the generic scaling approaches applicable to the existing processes and systems. This work analyses a large amount of the recent literature on graphene production by various techniques and summarizes the results in a tabular form to provide a simple and convenient comparison of several available techniques. Our analysis reveals a significant potential of scalability for plasma-based technologies, based on the scaling-related process characteristics. Among other processes, a greater yield of 1 g × h(-1) m(-2) was reached for the arc discharge technology, whereas the other plasma-based techniques show process yields comparable to the neutral-gas based methods. Selected plasma-based techniques show lower energy consumption than in thermal CVD processes, and the ability to produce graphene flakes of

Scalable and massively parallel Monte Carlo photon transport simulations for heterogeneous computing platforms.

Science.gov (United States)

Yu, Leiming; Nina-Paravecino, Fanny; Kaeli, David; Fang, Qianqian

2018-01-01

We present a highly scalable Monte Carlo (MC) three-dimensional photon transport simulation platform designed for heterogeneous computing systems. Through the development of a massively parallel MC algorithm using the Open Computing Language framework, this research extends our existing graphics processing unit (GPU)-accelerated MC technique to a highly scalable vendor-independent heterogeneous computing environment, achieving significantly improved performance and software portability. A number of parallel computing techniques are investigated to achieve portable performance over a wide range of computing hardware. Furthermore, multiple thread-level and device-level load-balancing strategies are developed to obtain efficient simulations using multiple central processing units and GPUs. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Advanced technologies for scalable ATLAS conditions database access on the grid

International Nuclear Information System (INIS)

Basset, R; Canali, L; Girone, M; Hawkings, R; Valassi, A; Viegas, F; Dimitrov, G; Nevski, P; Vaniachine, A; Walker, R; Wong, A

2010-01-01

During massive data reprocessing operations an ATLAS Conditions Database application must support concurrent access from numerous ATLAS data processing jobs running on the Grid. By simulating realistic work-flow, ATLAS database scalability tests provided feedback for Conditions Db software optimization and allowed precise determination of required distributed database resources. In distributed data processing one must take into account the chaotic nature of Grid computing characterized by peak loads, which can be much higher than average access rates. To validate database performance at peak loads, we tested database scalability at very high concurrent jobs rates. This has been achieved through coordinated database stress tests performed in series of ATLAS reprocessing exercises at the Tier-1 sites. The goal of database stress tests is to detect scalability limits of the hardware deployed at the Tier-1 sites, so that the server overload conditions can be safely avoided in a production environment. Our analysis of server performance under stress tests indicates that Conditions Db data access is limited by the disk I/O throughput. An unacceptable side-effect of the disk I/O saturation is a degradation of the WLCG 3D Services that update Conditions Db data at all ten ATLAS Tier-1 sites using the technology of Oracle Streams. To avoid such bottlenecks we prototyped and tested a novel approach for database peak load avoidance in Grid computing. Our approach is based upon the proven idea of pilot job submission on the Grid: instead of the actual query, an ATLAS utility library sends to the database server a pilot query first.

Scalable graphene aptasensors for drug quantification

Science.gov (United States)

Vishnubhotla, Ramya; Ping, Jinglei; Gao, Zhaoli; Lee, Abigail; Saouaf, Olivia; Vrudhula, Amey; Johnson, A. T. Charlie

2017-11-01

Simpler and more rapid approaches for therapeutic drug-level monitoring are highly desirable to enable use at the point-of-care. We have developed an all-electronic approach for detection of the HIV drug tenofovir based on scalable fabrication of arrays of graphene field-effect transistors (GFETs) functionalized with a commercially available DNA aptamer. The shift in the Dirac voltage of the GFETs varied systematically with the concentration of tenofovir in deionized water, with a detection limit less than 1 ng/mL. Tests against a set of negative controls confirmed the specificity of the sensor response. This approach offers the potential for further development into a rapid and convenient point-of-care tool with clinically relevant performance.

Scalable quantum search using trapped ions

International Nuclear Information System (INIS)

Ivanov, S. S.; Ivanov, P. A.; Linington, I. E.; Vitanov, N. V.

2010-01-01

We propose a scalable implementation of Grover's quantum search algorithm in a trapped-ion quantum information processor. The system is initialized in an entangled Dicke state by using adiabatic techniques. The inversion-about-average and oracle operators take the form of single off-resonant laser pulses. This is made possible by utilizing the physical symmetries of the trapped-ion linear crystal. The physical realization of the algorithm represents a dramatic simplification: each logical iteration (oracle and inversion about average) requires only two physical interaction steps, in contrast to the large number of concatenated gates required by previous approaches. This not only facilitates the implementation but also increases the overall fidelity of the algorithm.

Spatiotemporal Stochastic Modeling of IoT Enabled Cellular Networks: Scalability and Stability Analysis

KAUST Repository

Gharbieh, Mohammad; Elsawy, Hesham; Bader, Ahmed; Alouini, Mohamed-Slim

2017-01-01

The Internet of Things (IoT) is large-scale by nature, which is manifested by the massive number of connected devices as well as their vast spatial existence. Cellular networks, which provide ubiquitous, reliable, and efficient wireless access, will play fundamental rule in delivering the first-mile access for the data tsunami to be generated by the IoT. However, cellular networks may have scalability problems to provide uplink connectivity to massive numbers of connected things. To characterize the scalability of cellular uplink in the context of IoT networks, this paper develops a traffic-aware spatiotemporal mathematical model for IoT devices supported by cellular uplink connectivity. The developed model is based on stochastic geometry and queueing theory to account for the traffic requirement per IoT device, the different transmission strategies, and the mutual interference between the IoT devices. To this end, the developed model is utilized to characterize the extent to which cellular networks can accommodate IoT traffic as well as to assess and compare three different transmission strategies that incorporate a combination of transmission persistency, backoff, and power-ramping. The analysis and the results clearly illustrate the scalability problem imposed by IoT on cellular network and offer insights into effective scenarios for each transmission strategy.

Spatiotemporal Stochastic Modeling of IoT Enabled Cellular Networks: Scalability and Stability Analysis

KAUST Repository

Gharbieh, Mohammad

2017-05-02

The Internet of Things (IoT) is large-scale by nature, which is manifested by the massive number of connected devices as well as their vast spatial existence. Cellular networks, which provide ubiquitous, reliable, and efficient wireless access, will play fundamental rule in delivering the first-mile access for the data tsunami to be generated by the IoT. However, cellular networks may have scalability problems to provide uplink connectivity to massive numbers of connected things. To characterize the scalability of cellular uplink in the context of IoT networks, this paper develops a traffic-aware spatiotemporal mathematical model for IoT devices supported by cellular uplink connectivity. The developed model is based on stochastic geometry and queueing theory to account for the traffic requirement per IoT device, the different transmission strategies, and the mutual interference between the IoT devices. To this end, the developed model is utilized to characterize the extent to which cellular networks can accommodate IoT traffic as well as to assess and compare three different transmission strategies that incorporate a combination of transmission persistency, backoff, and power-ramping. The analysis and the results clearly illustrate the scalability problem imposed by IoT on cellular network and offer insights into effective scenarios for each transmission strategy.

Programming time-multiplexed reconfigurable hardware using a scalable neuromorphic compiler.

Science.gov (United States)

Minkovich, Kirill; Srinivasa, Narayan; Cruz-Albrecht, Jose M; Cho, Youngkwan; Nogin, Aleksey

2012-06-01

Scalability and connectivity are two key challenges in designing neuromorphic hardware that can match biological levels. In this paper, we describe a neuromorphic system architecture design that addresses an approach to meet these challenges using traditional complementary metal-oxide-semiconductor (CMOS) hardware. A key requirement in realizing such neural architectures in hardware is the ability to automatically configure the hardware to emulate any neural architecture or model. The focus for this paper is to describe the details of such a programmable front-end. This programmable front-end is composed of a neuromorphic compiler and a digital memory, and is designed based on the concept of synaptic time-multiplexing (STM). The neuromorphic compiler automatically translates any given neural architecture to hardware switch states and these states are stored in digital memory to enable desired neural architectures. STM enables our proposed architecture to address scalability and connectivity using traditional CMOS hardware. We describe the details of the proposed design and the programmable front-end, and provide examples to illustrate its capabilities. We also provide perspectives for future extensions and potential applications.

Disseminating NASA-based science through NASA's Universe of Learning: Girls STEAM Ahead

Science.gov (United States)

Marcucci, E.; Meinke, B. K.; Smith, D. A.; Ryer, H.; Slivinski, C.; Kenney, J.; Arcand, K.; Cominsky, L.

2017-12-01

The Girls STEAM Ahead with NASA (GSAWN) initiative partners the NASA's Universe of Learning (UoL) resources with public libraries to provide NASA-themed activities for girls and their families. The program expands upon the legacy program, NASA Science4Girls and Their Families, in celebration of National Women's History Month. Program resources include hands-on activities for engaging girls, such as coding experiences and use of remote telescopes, complementary exhibits, and professional development for library partner staff. The science-institute-embedded partners in NASA's UoL are uniquely poised to foster collaboration between scientists with content expertise and educators with pedagogy expertise. The thematic topics related to NASA Astrophysics enable audiences to experience the full range of NASA scientific and technical disciplines and the different career skills each requires. For example, an activity may focus on understanding exoplanets, methods of their detection, and characteristics that can be determined remotely. The events focus on engaging underserved and underrepresented audiences in Science, Technology, Engineering, and Mathematics (STEM) via use of research-based best practices, collaborations with libraries, partnerships with local and national organizations (e.g. National Girls Collaborative Project or NGCP), and remote engagement of audiences. NASA's UoL collaborated with another NASA STEM Activation partner, NASA@ My Library, to announce GSAWN to their extensive STAR_Net network of libraries. This partnership between NASA SMD-funded Science learning and literacy teams has included NASA@ My Library hosting a professional development webinar featuring a GSAWN activity, a newsletter and blog post about the program, and plans for future exhibit development. This presentation will provide an overview of the program's progress to engage girls and their families through the development and dissemination of NASA-based science programming.

GPU-FS-kNN: a software tool for fast and scalable kNN computation using GPUs.

Directory of Open Access Journals (Sweden)

Ahmed Shamsul Arefin

Full Text Available BACKGROUND: The analysis of biological networks has become a major challenge due to the recent development of high-throughput techniques that are rapidly producing very large data sets. The exploding volumes of biological data are craving for extreme computational power and special computing facilities (i.e. super-computers. An inexpensive solution, such as General Purpose computation based on Graphics Processing Units (GPGPU, can be adapted to tackle this challenge, but the limitation of the device internal memory can pose a new problem of scalability. An efficient data and computational parallelism with partitioning is required to provide a fast and scalable solution to this problem. RESULTS: We propose an efficient parallel formulation of the k-Nearest Neighbour (kNN search problem, which is a popular method for classifying objects in several fields of research, such as pattern recognition, machine learning and bioinformatics. Being very simple and straightforward, the performance of the kNN search degrades dramatically for large data sets, since the task is computationally intensive. The proposed approach is not only fast but also scalable to large-scale instances. Based on our approach, we implemented a software tool GPU-FS-kNN (GPU-based Fast and Scalable k-Nearest Neighbour for CUDA enabled GPUs. The basic approach is simple and adaptable to other available GPU architectures. We observed speed-ups of 50-60 times compared with CPU implementation on a well-known breast microarray study and its associated data sets. CONCLUSION: Our GPU-based Fast and Scalable k-Nearest Neighbour search technique (GPU-FS-kNN provides a significant performance improvement for nearest neighbour computation in large-scale networks. Source code and the software tool is available under GNU Public License (GPL at https://sourceforge.net/p/gpufsknn/.

A Scalable Communication Architecture for Advanced Metering Infrastructure

OpenAIRE

Ngo Hoang , Giang; Liquori , Luigi; Nguyen Chan , Hung

2013-01-01

Advanced Metering Infrastructure (AMI), seen as foundation for overall grid modernization, is an integration of many technologies that provides an intelligent connection between consumers and system operators [ami 2008]. One of the biggest challenge that AMI faces is to scalable collect and manage a huge amount of data from a large number of customers. In our paper, we address this challenge by introducing a mixed peer-to-peer (P2P) and client-server communication architecture for AMI in whic...

Neutron generators with size scalability, ease of fabrication and multiple ion source functionalities

Science.gov (United States)

Elizondo-Decanini, Juan M

2014-11-18

A neutron generator is provided with a flat, rectilinear geometry and surface mounted metallizations. This construction provides scalability and ease of fabrication, and permits multiple ion source functionalities.

The NASA Astrophysics Program

Science.gov (United States)

Zebulum, Ricardo S.

2011-01-01

NASA's scientists are enjoying unprecedented access to astronomy data from space, both from missions launched and operated only by NASA, as well as missions led by other space agencies to which NASA contributed instruments or technology. This paper describes the NASA astrophysics program for the next decade, including NASA's response to the ASTRO2010 Decadal Survey.

Scalable and Anonymous Group Communication with MTor

Directory of Open Access Journals (Sweden)

Lin Dong

2016-04-01

Full Text Available This paper presents MTor, a low-latency anonymous group communication system. We construct MTor as an extension to Tor, allowing the construction of multi-source multicast trees on top of the existing Tor infrastructure. MTor does not depend on an external service to broker the group communication, and avoids central points of failure and trust. MTor’s substantial bandwidth savings and graceful scalability enable new classes of anonymous applications that are currently too bandwidth-intensive to be viable through traditional unicast Tor communication-e.g., group file transfer, collaborative editing, streaming video, and real-time audio conferencing.

NASA systems engineering handbook

Science.gov (United States)

Shishko, Robert; Aster, Robert; Chamberlain, Robert G.; McDuffee, Patrick; Pieniazek, Les; Rowell, Tom; Bain, Beth; Cox, Renee I.; Mooz, Harold; Polaski, Lou

1995-06-01

This handbook brings the fundamental concepts and techniques of systems engineering to NASA personnel in a way that recognizes the nature of NASA systems and environment. It is intended to accompany formal NASA training courses on systems engineering and project management when appropriate, and is designed to be a top-level overview. The concepts were drawn from NASA field center handbooks, NMI's/NHB's, the work of the NASA-wide Systems Engineering Working Group and the Systems Engineering Process Improvement Task team, several non-NASA textbooks and guides, and material from independent systems engineering courses taught to NASA personnel. Five core chapters cover systems engineering fundamentals, the NASA Project Cycle, management issues in systems engineering, systems analysis and modeling, and specialty engineering integration. It is not intended as a directive.

Scalable Multifunction RF Systems: Combined vs. Separate Transmit and Receive Arrays

NARCIS (Netherlands)

Huizing, A.G.

2008-01-01

A scalable multifunction RF (SMRF) system allows the RF functionality (radar, electronic warfare and communications) to be easily extended and the RF performance to be scaled to the requirements of different missions and platforms. This paper presents the results of a trade-off study with respect to

Wideband vs. Multiband Trade-offs for a Scalable Multifunction RF system

NARCIS (Netherlands)

Huizing, A.G.

2005-01-01

This paper presents a concept for a scalable multifunction RF (SMRF) system that allows the RF functionality (radar, electronic warfare and communications) to be easily extended and the RF performance to be scaled to the requirements of different missions and platforms. A trade-off analysis is

Optimized bit extraction using distortion modeling in the scalable extension of H.264/AVC.

Science.gov (United States)

Maani, Ehsan; Katsaggelos, Aggelos K

2009-09-01

The newly adopted scalable extension of H.264/AVC video coding standard (SVC) demonstrates significant improvements in coding efficiency in addition to an increased degree of supported scalability relative to the scalable profiles of prior video coding standards. Due to the complicated hierarchical prediction structure of the SVC and the concept of key pictures, content-aware rate adaptation of SVC bit streams to intermediate bit rates is a nontrivial task. The concept of quality layers has been introduced in the design of the SVC to allow for fast content-aware prioritized rate adaptation. However, existing quality layer assignment methods are suboptimal and do not consider all network abstraction layer (NAL) units from different layers for the optimization. In this paper, we first propose a technique to accurately and efficiently estimate the quality degradation resulting from discarding an arbitrary number of NAL units from multiple layers of a bitstream by properly taking drift into account. Then, we utilize this distortion estimation technique to assign quality layers to NAL units for a more efficient extraction. Experimental results show that a significant gain can be achieved by the proposed scheme.

Scalable Generation of Universal Platelets from Human Induced Pluripotent Stem Cells

Directory of Open Access Journals (Sweden)

Qiang Feng

2014-11-01

Full Text Available Human induced pluripotent stem cells (iPSCs provide a potentially replenishable source for the production of transfusable platelets. Here, we describe a method to generate megakaryocytes (MKs and functional platelets from iPSCs in a scalable manner under serum/feeder-free conditions. The method also permits the cryopreservation of MK progenitors, enabling a rapid “surge” capacity when large numbers of platelets are needed. Ultrastructural/morphological analyses show no major differences between iPSC platelets and human blood platelets. iPSC platelets form aggregates, lamellipodia, and filopodia after activation and circulate in macrophage-depleted animals and incorporate into developing mouse thrombi in a manner identical to human platelets. By knocking out the β2-microglobulin gene, we have generated platelets that are negative for the major histocompatibility antigens. The scalable generation of HLA-ABC-negative platelets from a renewable cell source represents an important step toward generating universal platelets for transfusion as well as a potential strategy for the management of platelet refractoriness.

Scalable electrophysiology in intact small animals with nanoscale suspended electrode arrays

Science.gov (United States)

Gonzales, Daniel L.; Badhiwala, Krishna N.; Vercosa, Daniel G.; Avants, Benjamin W.; Liu, Zheng; Zhong, Weiwei; Robinson, Jacob T.

2017-07-01

Electrical measurements from large populations of animals would help reveal fundamental properties of the nervous system and neurological diseases. Small invertebrates are ideal for these large-scale studies; however, patch-clamp electrophysiology in microscopic animals typically requires invasive dissections and is low-throughput. To overcome these limitations, we present nano-SPEARs: suspended electrodes integrated into a scalable microfluidic device. Using this technology, we have made the first extracellular recordings of body-wall muscle electrophysiology inside an intact roundworm, Caenorhabditis elegans. We can also use nano-SPEARs to record from multiple animals in parallel and even from other species, such as Hydra littoralis. Furthermore, we use nano-SPEARs to establish the first electrophysiological phenotypes for C. elegans models for amyotrophic lateral sclerosis and Parkinson's disease, and show a partial rescue of the Parkinson's phenotype through drug treatment. These results demonstrate that nano-SPEARs provide the core technology for microchips that enable scalable, in vivo studies of neurobiology and neurological diseases.

High-Lift Propeller System Configuration Selection for NASA's SCEPTOR Distributed Electric Propulsion Flight Demonstrator

Science.gov (United States)

Patterson, Michael D.; Derlaga, Joseph M.; Borer, Nicholas K.

2016-01-01

Although the primary function of propellers is typically to produce thrust, aircraft equipped with distributed electric propulsion (DEP) may utilize propellers whose main purpose is to act as a form of high-lift device. These \\high-lift propellers" can be placed upstream of wing such that, when the higher-velocity ow in the propellers' slipstreams interacts with the wing, the lift is increased. This technique is a main design feature of a new NASA advanced design project called Scalable Convergent Electric Propulsion Technology Operations Research (SCEPTOR). The goal of the SCEPTOR project is design, build, and y a DEP aircraft to demonstrate that such an aircraft can be much more ecient than conventional designs. This paper provides details into the high-lift propeller system con guration selection for the SCEPTOR ight demonstrator. The methods used in the high-lift propeller system conceptual design and the tradeo s considered in selecting the number of propellers are discussed.

Particle Communication and Domain Neighbor Coupling: Scalable Domain Decomposed Algorithms for Monte Carlo Particle Transport

Energy Technology Data Exchange (ETDEWEB)

O' Brien, M. J.; Brantley, P. S.

2015-01-20

In order to run Monte Carlo particle transport calculations on new supercomputers with hundreds of thousands or millions of processors, care must be taken to implement scalable algorithms. This means that the algorithms must continue to perform well as the processor count increases. In this paper, we examine the scalability of:(1) globally resolving the particle locations on the correct processor, (2) deciding that particle streaming communication has finished, and (3) efficiently coupling neighbor domains together with different replication levels. We have run domain decomposed Monte Carlo particle transport on up to 2²¹ = 2,097,152 MPI processes on the IBM BG/Q Sequoia supercomputer and observed scalable results that agree with our theoretical predictions. These calculations were carefully constructed to have the same amount of work on every processor, i.e. the calculation is already load balanced. We also examine load imbalanced calculations where each domain’s replication level is proportional to its particle workload. In this case we show how to efficiently couple together adjacent domains to maintain within workgroup load balance and minimize memory usage.

Scalable video on demand adaptive Internet-based distribution

CERN Document Server

Zink, Michael

2013-01-01

In recent years, the proliferation of available video content and the popularity of the Internet have encouraged service providers to develop new ways of distributing content to clients. Increasing video scaling ratios and advanced digital signal processing techniques have led to Internet Video-on-Demand applications, but these currently lack efficiency and quality. Scalable Video on Demand: Adaptive Internet-based Distribution examines how current video compression and streaming can be used to deliver high-quality applications over the Internet. In addition to analysing the problems

Parallelism and Scalability in an Image Processing Application

DEFF Research Database (Denmark)

Rasmussen, Morten Sleth; Stuart, Matthias Bo; Karlsson, Sven

2008-01-01

parallel programs. This paper investigates parallelism and scalability of an embedded image processing application. The major challenges faced when parallelizing the application were to extract enough parallelism from the application and to reduce load imbalance. The application has limited immediately......The recent trends in processor architecture show that parallel processing is moving into new areas of computing in the form of many-core desktop processors and multi-processor system-on-chip. This means that parallel processing is required in application areas that traditionally have not used...

Parallelism and Scalability in an Image Processing Application

DEFF Research Database (Denmark)

Rasmussen, Morten Sleth; Stuart, Matthias Bo; Karlsson, Sven

2009-01-01

parallel programs. This paper investigates parallelism and scalability of an embedded image processing application. The major challenges faced when parallelizing the application were to extract enough parallelism from the application and to reduce load imbalance. The application has limited immediately......The recent trends in processor architecture show that parallel processing is moving into new areas of computing in the form of many-core desktop processors and multi-processor system-on-chips. This means that parallel processing is required in application areas that traditionally have not used...

Scalable microcarrier-based manufacturing of mesenchymal stem/stromal cells.

Science.gov (United States)

de Soure, António M; Fernandes-Platzgummer, Ana; da Silva, Cláudia L; Cabral, Joaquim M S

2016-10-20

Due to their unique features, mesenchymal stem/stromal cells (MSC) have been exploited in clinical settings as therapeutic candidates for the treatment of a variety of diseases. However, the success in obtaining clinically-relevant MSC numbers for cell-based therapies is dependent on efficient isolation and ex vivo expansion protocols, able to comply with good manufacturing practices (GMP). In this context, the 2-dimensional static culture systems typically used for the expansion of these cells present several limitations that may lead to reduced cell numbers and compromise cell functions. Furthermore, many studies in the literature report the expansion of MSC using fetal bovine serum (FBS)-supplemented medium, which has been critically rated by regulatory agencies. Alternative platforms for the scalable manufacturing of MSC have been developed, namely using microcarriers in bioreactors, with also a considerable number of studies now reporting the production of MSC using xenogeneic/serum-free medium formulations. In this review we provide a comprehensive overview on the scalable manufacturing of human mesenchymal stem/stromal cells, depicting the various steps involved in the process from cell isolation to ex vivo expansion, using different cell tissue sources and culture medium formulations and exploiting bioprocess engineering tools namely microcarrier technology and bioreactors. Copyright © 2016 Elsevier B.V. All rights reserved.

A highly scalable peptide-based assay system for proteomics.

Directory of Open Access Journals (Sweden)

Igor A Kozlov

Full Text Available We report a scalable and cost-effective technology for generating and screening high-complexity customizable peptide sets. The peptides are made as peptide-cDNA fusions by in vitro transcription/translation from pools of DNA templates generated by microarray-based synthesis. This approach enables large custom sets of peptides to be designed in silico, manufactured cost-effectively in parallel, and assayed efficiently in a multiplexed fashion. The utility of our peptide-cDNA fusion pools was demonstrated in two activity-based assays designed to discover protease and kinase substrates. In the protease assay, cleaved peptide substrates were separated from uncleaved and identified by digital sequencing of their cognate cDNAs. We screened the 3,011 amino acid HCV proteome for susceptibility to cleavage by the HCV NS3/4A protease and identified all 3 known trans cleavage sites with high specificity. In the kinase assay, peptide substrates phosphorylated by tyrosine kinases were captured and identified by sequencing of their cDNAs. We screened a pool of 3,243 peptides against Abl kinase and showed that phosphorylation events detected were specific and consistent with the known substrate preferences of Abl kinase. Our approach is scalable and adaptable to other protein-based assays.

Scalable Nernst thermoelectric power using a coiled galfenol wire

Science.gov (United States)

Yang, Zihao; Codecido, Emilio A.; Marquez, Jason; Zheng, Yuanhua; Heremans, Joseph P.; Myers, Roberto C.

2017-09-01

The Nernst thermopower usually is considered far too weak in most metals for waste heat recovery. However, its transverse orientation gives it an advantage over the Seebeck effect on non-flat surfaces. Here, we experimentally demonstrate the scalable generation of a Nernst voltage in an air-cooled metal wire coiled around a hot cylinder. In this geometry, a radial temperature gradient generates an azimuthal electric field in the coil. A Galfenol (Fe0.85Ga0.15) wire is wrapped around a cartridge heater, and the voltage drop across the wire is measured as a function of axial magnetic field. As expected, the Nernst voltage scales linearly with the length of the wire. Based on heat conduction and fluid dynamic equations, finite-element method is used to calculate the temperature gradient across the Galfenol wire and determine the Nernst coefficient. A giant Nernst coefficient of -2.6 μV/KT at room temperature is estimated, in agreement with measurements on bulk Galfenol. We expect that the giant Nernst effect in Galfenol arises from its magnetostriction, presumably through enhanced magnon-phonon coupling. Our results demonstrate the feasibility of a transverse thermoelectric generator capable of scalable output power from non-flat heat sources.

Scalable Nernst thermoelectric power using a coiled galfenol wire

Directory of Open Access Journals (Sweden)

Zihao Yang

2017-09-01

Full Text Available The Nernst thermopower usually is considered far too weak in most metals for waste heat recovery. However, its transverse orientation gives it an advantage over the Seebeck effect on non-flat surfaces. Here, we experimentally demonstrate the scalable generation of a Nernst voltage in an air-cooled metal wire coiled around a hot cylinder. In this geometry, a radial temperature gradient generates an azimuthal electric field in the coil. A Galfenol (Fe0.85Ga0.15 wire is wrapped around a cartridge heater, and the voltage drop across the wire is measured as a function of axial magnetic field. As expected, the Nernst voltage scales linearly with the length of the wire. Based on heat conduction and fluid dynamic equations, finite-element method is used to calculate the temperature gradient across the Galfenol wire and determine the Nernst coefficient. A giant Nernst coefficient of -2.6 μV/KT at room temperature is estimated, in agreement with measurements on bulk Galfenol. We expect that the giant Nernst effect in Galfenol arises from its magnetostriction, presumably through enhanced magnon-phonon coupling. Our results demonstrate the feasibility of a transverse thermoelectric generator capable of scalable output power from non-flat heat sources.

Continuous flow photocyclization of stilbenes – scalable synthesis of functionalized phenanthrenes and helicenes

Directory of Open Access Journals (Sweden)

Quentin Lefebvre

2013-09-01

Full Text Available A continuous flow oxidative photocyclization of stilbene derivatives has been developed which allows the scalable synthesis of backbone functionalized phenanthrenes and helicenes of various sizes in good yields.

Scalable Multi-group Key Management for Advanced Metering Infrastructure

OpenAIRE

Benmalek , Mourad; Challal , Yacine; Bouabdallah , Abdelmadjid

2015-01-01

International audience; Advanced Metering Infrastructure (AMI) is composed of systems and networks to incorporate changes for modernizing the electricity grid, reduce peak loads, and meet energy efficiency targets. AMI is a privileged target for security attacks with potentially great damage against infrastructures and privacy. For this reason, Key Management has been identified as one of the most challenging topics in AMI development. In this paper, we propose a new Scalable multi-group key ...

Towards Scalable Strain Gauge-Based Joint Torque Sensors

Science.gov (United States)

D’Imperio, Mariapaola; Cannella, Ferdinando; Caldwell, Darwin G.; Cuschieri, Alfred

2017-01-01

During recent decades, strain gauge-based joint torque sensors have been commonly used to provide high-fidelity torque measurements in robotics. Although measurement of joint torque/force is often required in engineering research and development, the gluing and wiring of strain gauges used as torque sensors pose difficulties during integration within the restricted space available in small joints. The problem is compounded by the need for a scalable geometric design to measure joint torque. In this communication, we describe a novel design of a strain gauge-based mono-axial torque sensor referred to as square-cut torque sensor (SCTS), the significant features of which are high degree of linearity, symmetry, and high scalability in terms of both size and measuring range. Most importantly, SCTS provides easy access for gluing and wiring of the strain gauges on sensor surface despite the limited available space. We demonstrated that the SCTS was better in terms of symmetry (clockwise and counterclockwise rotation) and more linear. These capabilities have been shown through finite element modeling (ANSYS) confirmed by observed data obtained by load testing experiments. The high performance of SCTS was confirmed by studies involving changes in size, material and/or wings width and thickness. Finally, we demonstrated that the SCTS can be successfully implementation inside the hip joints of miniaturized hydraulically actuated quadruped robot-MiniHyQ. This communication is based on work presented at the 18th International Conference on Climbing and Walking Robots (CLAWAR). PMID:28820446

Scalable parallel prefix solvers for discrete ordinates transport

International Nuclear Information System (INIS)

Pautz, S.; Pandya, T.; Adams, M.

2009-01-01

The well-known 'sweep' algorithm for inverting the streaming-plus-collision term in first-order deterministic radiation transport calculations has some desirable numerical properties. However, it suffers from parallel scaling issues caused by a lack of concurrency. The maximum degree of concurrency, and thus the maximum parallelism, grows more slowly than the problem size for sweeps-based solvers. We investigate a new class of parallel algorithms that involves recasting the streaming-plus-collision problem in prefix form and solving via cyclic reduction. This method, although computationally more expensive at low levels of parallelism than the sweep algorithm, offers better theoretical scalability properties. Previous work has demonstrated this approach for one-dimensional calculations; we show how to extend it to multidimensional calculations. Notably, for multiple dimensions it appears that this approach is limited to long-characteristics discretizations; other discretizations cannot be cast in prefix form. We implement two variants of the algorithm within the radlib/SCEPTRE transport code library at Sandia National Laboratories and show results on two different massively parallel systems. Both the 'forward' and 'symmetric' solvers behave similarly, scaling well to larger degrees of parallelism then sweeps-based solvers. We do observe some issues at the highest levels of parallelism (relative to the system size) and discuss possible causes. We conclude that this approach shows good potential for future parallel systems, but the parallel scalability will depend heavily on the architecture of the communication networks of these systems. (authors)

Vocal activity as a low cost and scalable index of seabird colony size.

Science.gov (United States)

Borker, Abraham L; McKown, Matthew W; Ackerman, Joshua T; Eagles-Smith, Collin A; Tershy, Bernie R; Croll, Donald A

2014-08-01

Although wildlife conservation actions have increased globally in number and complexity, the lack of scalable, cost-effective monitoring methods limits adaptive management and the evaluation of conservation efficacy. Automated sensors and computer-aided analyses provide a scalable and increasingly cost-effective tool for conservation monitoring. A key assumption of automated acoustic monitoring of birds is that measures of acoustic activity at colony sites are correlated with the relative abundance of nesting birds. We tested this assumption for nesting Forster's terns (Sterna forsteri) in San Francisco Bay for 2 breeding seasons. Sensors recorded ambient sound at 7 colonies that had 15-111 nests in 2009 and 2010. Colonies were spaced at least 250 m apart and ranged from 36 to 2,571 m(2) . We used spectrogram cross-correlation to automate the detection of tern calls from recordings. We calculated mean seasonal call rate and compared it with mean active nest count at each colony. Acoustic activity explained 71% of the variation in nest abundance between breeding sites and 88% of the change in colony size between years. These results validate a primary assumption of acoustic indices; that is, for terns, acoustic activity is correlated to relative abundance, a fundamental step toward designing rigorous and scalable acoustic monitoring programs to measure the effectiveness of conservation actions for colonial birds and other acoustically active wildlife. © 2014 Society for Conservation Biology.

Design for Scalability: A Case Study of the River City Curriculum

Science.gov (United States)

Clarke, Jody; Dede, Chris

2009-01-01

One-size-fits-all educational innovations do not work because they ignore contextual factors that determine an intervention's efficacy in a particular local situation. This paper presents a framework on how to design educational innovations for scalability through enhancing their adaptability for effective usage in a wide variety of settings. The…

Interactive segmentation: a scalable superpixel-based method

Science.gov (United States)

Mathieu, Bérengère; Crouzil, Alain; Puel, Jean-Baptiste

2017-11-01

This paper addresses the problem of interactive multiclass segmentation of images. We propose a fast and efficient new interactive segmentation method called superpixel α fusion (SαF). From a few strokes drawn by a user over an image, this method extracts relevant semantic objects. To get a fast calculation and an accurate segmentation, SαF uses superpixel oversegmentation and support vector machine classification. We compare SαF with competing algorithms by evaluating its performances on reference benchmarks. We also suggest four new datasets to evaluate the scalability of interactive segmentation methods, using images from some thousand to several million pixels. We conclude with two applications of SαF.

geoKepler Workflow Module for Computationally Scalable and Reproducible Geoprocessing and Modeling

Science.gov (United States)

Cowart, C.; Block, J.; Crawl, D.; Graham, J.; Gupta, A.; Nguyen, M.; de Callafon, R.; Smarr, L.; Altintas, I.

2015-12-01

The NSF-funded WIFIRE project has developed an open-source, online geospatial workflow platform for unifying geoprocessing tools and models for for fire and other geospatially dependent modeling applications. It is a product of WIFIRE's objective to build an end-to-end cyberinfrastructure for real-time and data-driven simulation, prediction and visualization of wildfire behavior. geoKepler includes a set of reusable GIS components, or actors, for the Kepler Scientific Workflow System (https://kepler-project.org). Actors exist for reading and writing GIS data in formats such as Shapefile, GeoJSON, KML, and using OGC web services such as WFS. The actors also allow for calling geoprocessing tools in other packages such as GDAL and GRASS. Kepler integrates functions from multiple platforms and file formats into one framework, thus enabling optimal GIS interoperability, model coupling, and scalability. Products of the GIS actors can be fed directly to models such as FARSITE and WRF. Kepler's ability to schedule and scale processes using Hadoop and Spark also makes geoprocessing ultimately extensible and computationally scalable. The reusable workflows in geoKepler can be made to run automatically when alerted by real-time environmental conditions. Here, we show breakthroughs in the speed of creating complex data for hazard assessments with this platform. We also demonstrate geoKepler workflows that use Data Assimilation to ingest real-time weather data into wildfire simulations, and for data mining techniques to gain insight into environmental conditions affecting fire behavior. Existing machine learning tools and libraries such as R and MLlib are being leveraged for this purpose in Kepler, as well as Kepler's Distributed Data Parallel (DDP) capability to provide a framework for scalable processing. geoKepler workflows can be executed via an iPython notebook as a part of a Jupyter hub at UC San Diego for sharing and reporting of the scientific analysis and results from

NASA's Earth Science Gateway: A Platform for Interoperable Services in Support of the GEOSS Architecture

Science.gov (United States)

Alameh, N.; Bambacus, M.; Cole, M.

2006-12-01

Nasa's Earth Science as well as interdisciplinary research and applications activities require access to earth observations, analytical models and specialized tools and services, from diverse distributed sources. Interoperability and open standards for geospatial data access and processing greatly facilitate such access among the information and processing compo¬nents related to space¬craft, airborne, and in situ sensors; predictive models; and decision support tools. To support this mission, NASA's Geosciences Interoperability Office (GIO) has been developing the Earth Science Gateway (ESG; online at http://esg.gsfc.nasa.gov) by adapting and deploying a standards-based commercial product. Thanks to extensive use of open standards, ESG can tap into a wide array of online data services, serve a variety of audiences and purposes, and adapt to technology and business changes. Most importantly, the use of open standards allow ESG to function as a platform within a larger context of distributed geoscience processing, such as the Global Earth Observing System of Systems (GEOSS). ESG shares the goals of GEOSS to ensure that observations and products shared by users will be accessible, comparable, and understandable by relying on common standards and adaptation to user needs. By maximizing interoperability, modularity, extensibility and scalability, ESG's architecture fully supports the stated goals of GEOSS. As such, ESG's role extends beyond that of a gateway to NASA science data to become a shared platform that can be leveraged by GEOSS via: A modular and extensible architecture Consensus and community-based standards (e.g. ISO and OGC standards) A variety of clients and visualization techniques, including WorldWind and Google Earth A variety of services (including catalogs) with standard interfaces Data integration and interoperability Mechanisms for user involvement and collaboration Mechanisms for supporting interdisciplinary and domain-specific applications ESG

Scalability of a Low-Cost Multi-Teraflop Linux Cluster for High-End Classical Atomistic and Quantum Mechanical Simulations

Science.gov (United States)

Kikuchi, Hideaki; Kalia, Rajiv K.; Nakano, Aiichiro; Vashishta, Priya; Shimojo, Fuyuki; Saini, Subhash

2003-01-01

Scalability of a low-cost, Intel Xeon-based, multi-Teraflop Linux cluster is tested for two high-end scientific applications: Classical atomistic simulation based on the molecular dynamics method and quantum mechanical calculation based on the density functional theory. These scalable parallel applications use space-time multiresolution algorithms and feature computational-space decomposition, wavelet-based adaptive load balancing, and spacefilling-curve-based data compression for scalable I/O. Comparative performance tests are performed on a 1,024-processor Linux cluster and a conventional higher-end parallel supercomputer, 1,184-processor IBM SP4. The results show that the performance of the Linux cluster is comparable to that of the SP4. We also study various effects, such as the sharing of memory and L2 cache among processors, on the performance.

NASA reports

Science.gov (United States)

Obrien, John E.; Fisk, Lennard A.; Aldrich, Arnold A.; Utsman, Thomas E.; Griffin, Michael D.; Cohen, Aaron

1992-01-01

Activities and National Aeronautics and Space Administration (NASA) programs, both ongoing and planned, are described by NASA administrative personnel from the offices of Space Science and Applications, Space Systems Development, Space Flight, Exploration, and from the Johnson Space Center. NASA's multi-year strategic plan, called Vision 21, is also discussed. It proposes to use the unique perspective of space to better understand Earth. Among the NASA programs mentioned are the Magellan to Venus and Galileo to Jupiter spacecraft, the Cosmic Background Explorer, Pegsat (the first Pegasus payload), Hubble, the Joint U.S./German ROSAT X-ray Mission, Ulysses to Jupiter and over the sun, the Astro-Spacelab Mission, and the Gamma Ray Observatory. Copies of viewgraphs that illustrate some of these missions, and others, are provided. Also discussed were life science research plans, economic factors as they relate to space missions, and the outlook for international cooperation.

On eliminating synchronous communication in molecular simulations to improve scalability

Science.gov (United States)

Straatsma, T. P.; Chavarría-Miranda, Daniel G.

2013-12-01

Molecular dynamics simulation, as a complementary tool to experimentation, has become an important methodology for the understanding and design of molecular systems as it provides access to properties that are difficult, impossible or prohibitively expensive to obtain experimentally. Many of the available software packages have been parallelized to take advantage of modern massively concurrent processing resources. The challenge in achieving parallel efficiency is commonly attributed to the fact that molecular dynamics algorithms are communication intensive. This paper illustrates how an appropriately chosen data distribution and asynchronous one-sided communication approach can be used to effectively deal with the data movement within the Global Arrays/ARMCI programming model framework. A new put_notify capability is presented here, allowing the implementation of the molecular dynamics algorithm without any explicit global or local synchronization or global data reduction operations. In addition, this push-data model is shown to very effectively allow hiding data communication behind computation. Rather than data movement or explicit global reductions, the implicit synchronization of the algorithm becomes the primary challenge for scalability. Without any explicit synchronous operations, the scalability of molecular simulations is shown to depend only on the ability to evenly balance computational load.

Development of a scalable suspension culture for cardiac differentiation from human pluripotent stem cells

Directory of Open Access Journals (Sweden)

Vincent C. Chen

2015-09-01

Full Text Available To meet the need of a large quantity of hPSC-derived cardiomyocytes (CM for pre-clinical and clinical studies, a robust and scalable differentiation system for CM production is essential. With a human pluripotent stem cells (hPSC aggregate suspension culture system we established previously, we developed a matrix-free, scalable, and GMP-compliant process for directing hPSC differentiation to CM in suspension culture by modulating Wnt pathways with small molecules. By optimizing critical process parameters including: cell aggregate size, small molecule concentrations, induction timing, and agitation rate, we were able to consistently differentiate hPSCs to >90% CM purity with an average yield of 1.5 to 2 × 109 CM/L at scales up to 1 L spinner flasks. CM generated from the suspension culture displayed typical genetic, morphological, and electrophysiological cardiac cell characteristics. This suspension culture system allows seamless transition from hPSC expansion to CM differentiation in a continuous suspension culture. It not only provides a cost and labor effective scalable process for large scale CM production, but also provides a bioreactor prototype for automation of cell manufacturing, which will accelerate the advance of hPSC research towards therapeutic applications.

NASA's Global Imagery Browse Services - Technologies for Visualizing Earth Science Data

Science.gov (United States)

Cechini, M. F.; Boller, R. A.; Baynes, K.; Schmaltz, J. E.; Thompson, C. K.; Roberts, J. T.; Rodriguez, J.; Wong, M. M.; King, B. A.; King, J.; De Luca, A. P.; Pressley, N. N.

2017-12-01

For more than 20 years, the NASA Earth Observing System (EOS) has collected earth science data for thousands of scientific parameters now totaling nearly 15 Petabytes of data. In 2013, NASA's Global Imagery Browse Services (GIBS) formed its vision to "transform how end users interact and discover [EOS] data through visualizations." This vision included leveraging scientific and community best practices and standards to provide a scalable, compliant, and authoritative source for EOS earth science data visualizations. Since that time, GIBS has grown quickly and now services millions of daily requests for over 500 imagery layers representing hundreds of earth science parameters to a broad community of users. For many of these parameters, visualizations are available within hours of acquisition from the satellite. For others, visualizations are available for the entire mission of the satellite. The GIBS system is built upon the OnEarth and MRF open source software projects, which are provided by the GIBS team. This software facilitates standards-based access for compliance with existing GIS tools. The GIBS imagery layers are predominantly rasterized images represented in two-dimensional coordinate systems, though multiple projections are supported. The OnEarth software also supports the GIBS ingest pipeline to facilitate low latency updates to new or updated visualizations. This presentation will focus on the following topics: Overview of GIBS visualizations and user community Current benefits and limitations of the OnEarth and MRF software projects and related standards GIBS access methods and their in/compatibilities with existing GIS libraries and applications Considerations for visualization accuracy and understandability Future plans for more advanced visualization concepts including Vertical Profiles and Vector-Based Representations Future plans for Amazon Web Service support and deployments

Economical and scalable synthesis of 6-amino-2-cyanobenzothiazole

Directory of Open Access Journals (Sweden)

Jacob R. Hauser

2016-09-01

Full Text Available 2-Cyanobenzothiazoles (CBTs are useful building blocks for: 1 luciferin derivatives for bioluminescent imaging; and 2 handles for bioorthogonal ligations. A particularly versatile CBT is 6-amino-2-cyanobenzothiazole (ACBT, which has an amine handle for straight-forward derivatisation. Here we present an economical and scalable synthesis of ACBT based on a cyanation catalysed by 1,4-diazabicyclo[2.2.2]octane (DABCO, and discuss its advantages for scale-up over previously reported routes.

Architectural Techniques to Enable Reliable and Scalable Memory Systems

OpenAIRE

Nair, Prashant J.

2017-01-01

High capacity and scalable memory systems play a vital role in enabling our desktops, smartphones, and pervasive technologies like Internet of Things (IoT). Unfortunately, memory systems are becoming increasingly prone to faults. This is because we rely on technology scaling to improve memory density, and at small feature sizes, memory cells tend to break easily. Today, memory reliability is seen as the key impediment towards using high-density devices, adopting new technologies, and even bui...

Efficient Delivery of Scalable Video Using a Streaming Class Model

Directory of Open Access Journals (Sweden)

Jason J. Quinlan

2018-03-01

Full Text Available When we couple the rise in video streaming with the growing number of portable devices (smart phones, tablets, laptops, we see an ever-increasing demand for high-definition video online while on the move. Wireless networks are inherently characterised by restricted shared bandwidth and relatively high error loss rates, thus presenting a challenge for the efficient delivery of high quality video. Additionally, mobile devices can support/demand a range of video resolutions and qualities. This demand for mobile streaming highlights the need for adaptive video streaming schemes that can adjust to available bandwidth and heterogeneity, and can provide a graceful changes in video quality, all while respecting viewing satisfaction. In this context, the use of well-known scalable/layered media streaming techniques, commonly known as scalable video coding (SVC, is an attractive solution. SVC encodes a number of video quality levels within a single media stream. This has been shown to be an especially effective and efficient solution, but it fares badly in the presence of datagram losses. While multiple description coding (MDC can reduce the effects of packet loss on scalable video delivery, the increased delivery cost is counterproductive for constrained networks. This situation is accentuated in cases where only the lower quality level is required. In this paper, we assess these issues and propose a new approach called Streaming Classes (SC through which we can define a key set of quality levels, each of which can be delivered in a self-contained manner. This facilitates efficient delivery, yielding reduced transmission byte-cost for devices requiring lower quality, relative to MDC and Adaptive Layer Distribution (ALD (42% and 76% respective reduction for layer 2, while also maintaining high levels of consistent quality. We also illustrate how selective packetisation technique can further reduce the effects of packet loss on viewable quality by

Towards scalable quantum communication and computation: Novel approaches and realizations

Science.gov (United States)

Jiang, Liang

Quantum information science involves exploration of fundamental laws of quantum mechanics for information processing tasks. This thesis presents several new approaches towards scalable quantum information processing. First, we consider a hybrid approach to scalable quantum computation, based on an optically connected network of few-qubit quantum registers. Specifically, we develop a novel scheme for scalable quantum computation that is robust against various imperfections. To justify that nitrogen-vacancy (NV) color centers in diamond can be a promising realization of the few-qubit quantum register, we show how to isolate a few proximal nuclear spins from the rest of the environment and use them for the quantum register. We also demonstrate experimentally that the nuclear spin coherence is only weakly perturbed under optical illumination, which allows us to implement quantum logical operations that use the nuclear spins to assist the repetitive-readout of the electronic spin. Using this technique, we demonstrate more than two-fold improvement in signal-to-noise ratio. Apart from direct application to enhance the sensitivity of the NV-based nano-magnetometer, this experiment represents an important step towards the realization of robust quantum information processors using electronic and nuclear spin qubits. We then study realizations of quantum repeaters for long distance quantum communication. Specifically, we develop an efficient scheme for quantum repeaters based on atomic ensembles. We use dynamic programming to optimize various quantum repeater protocols. In addition, we propose a new protocol of quantum repeater with encoding, which efficiently uses local resources (about 100 qubits) to identify and correct errors, to achieve fast one-way quantum communication over long distances. Finally, we explore quantum systems with topological order. Such systems can exhibit remarkable phenomena such as quasiparticles with anyonic statistics and have been proposed as

Parallel scalability of Hartree-Fock calculations

Science.gov (United States)

Chow, Edmond; Liu, Xing; Smelyanskiy, Mikhail; Hammond, Jeff R.

2015-03-01

Quantum chemistry is increasingly performed using large cluster computers consisting of multiple interconnected nodes. For a fixed molecular problem, the efficiency of a calculation usually decreases as more nodes are used, due to the cost of communication between the nodes. This paper empirically investigates the parallel scalability of Hartree-Fock calculations. The construction of the Fock matrix and the density matrix calculation are analyzed separately. For the former, we use a parallelization of Fock matrix construction based on a static partitioning of work followed by a work stealing phase. For the latter, we use density matrix purification from the linear scaling methods literature, but without using sparsity. When using large numbers of nodes for moderately sized problems, density matrix computations are network-bandwidth bound, making purification methods potentially faster than eigendecomposition methods.

ParaText : scalable solutions for processing and searching very large document collections : final LDRD report.

Energy Technology Data Exchange (ETDEWEB)

Crossno, Patricia Joyce; Dunlavy, Daniel M.; Stanton, Eric T.; Shead, Timothy M.

2010-09-01

This report is a summary of the accomplishments of the 'Scalable Solutions for Processing and Searching Very Large Document Collections' LDRD, which ran from FY08 through FY10. Our goal was to investigate scalable text analysis; specifically, methods for information retrieval and visualization that could scale to extremely large document collections. Towards that end, we designed, implemented, and demonstrated a scalable framework for text analysis - ParaText - as a major project deliverable. Further, we demonstrated the benefits of using visual analysis in text analysis algorithm development, improved performance of heterogeneous ensemble models in data classification problems, and the advantages of information theoretic methods in user analysis and interpretation in cross language information retrieval. The project involved 5 members of the technical staff and 3 summer interns (including one who worked two summers). It resulted in a total of 14 publications, 3 new software libraries (2 open source and 1 internal to Sandia), several new end-user software applications, and over 20 presentations. Several follow-on projects have already begun or will start in FY11, with additional projects currently in proposal.

The development of a scalable parallel 3-D CFD algorithm for turbomachinery. M.S. Thesis Final Report

Science.gov (United States)

Luke, Edward Allen

1993-01-01

Two algorithms capable of computing a transonic 3-D inviscid flow field about rotating machines are considered for parallel implementation. During the study of these algorithms, a significant new method of measuring the performance of parallel algorithms is developed. The theory that supports this new method creates an empirical definition of scalable parallel algorithms that is used to produce quantifiable evidence that a scalable parallel application was developed. The implementation of the parallel application and an automated domain decomposition tool are also discussed.

A Scalable Framework to Detect Personal Health Mentions on Twitter.

Science.gov (United States)

Yin, Zhijun; Fabbri, Daniel; Rosenbloom, S Trent; Malin, Bradley

2015-06-05

Biomedical research has traditionally been conducted via surveys and the analysis of medical records. However, these resources are limited in their content, such that non-traditional domains (eg, online forums and social media) have an opportunity to supplement the view of an individual's health. The objective of this study was to develop a scalable framework to detect personal health status mentions on Twitter and assess the extent to which such information is disclosed. We collected more than 250 million tweets via the Twitter streaming API over a 2-month period in 2014. The corpus was filtered down to approximately 250,000 tweets, stratified across 34 high-impact health issues, based on guidance from the Medical Expenditure Panel Survey. We created a labeled corpus of several thousand tweets via a survey, administered over Amazon Mechanical Turk, that documents when terms correspond to mentions of personal health issues or an alternative (eg, a metaphor). We engineered a scalable classifier for personal health mentions via feature selection and assessed its potential over the health issues. We further investigated the utility of the tweets by determining the extent to which Twitter users disclose personal health status. Our investigation yielded several notable findings. First, we find that tweets from a small subset of the health issues can train a scalable classifier to detect health mentions. Specifically, training on 2000 tweets from four health issues (cancer, depression, hypertension, and leukemia) yielded a classifier with precision of 0.77 on all 34 health issues. Second, Twitter users disclosed personal health status for all health issues. Notably, personal health status was disclosed over 50% of the time for 11 out of 34 (33%) investigated health issues. Third, the disclosure rate was dependent on the health issue in a statistically significant manner (P<.001). For instance, more than 80% of the tweets about migraines (83/100) and allergies (85

Scalable Nonlinear Compact Schemes

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Debojyoti [Argonne National Lab. (ANL), Argonne, IL (United States); Constantinescu, Emil M. [Univ. of Chicago, IL (United States); Brown, Jed [Univ. of Colorado, Boulder, CO (United States)

2014-04-01

In this work, we focus on compact schemes resulting in tridiagonal systems of equations, specifically the fifth-order CRWENO scheme. We propose a scalable implementation of the nonlinear compact schemes by implementing a parallel tridiagonal solver based on the partitioning/substructuring approach. We use an iterative solver for the reduced system of equations; however, we solve this system to machine zero accuracy to ensure that no parallelization errors are introduced. It is possible to achieve machine-zero convergence with few iterations because of the diagonal dominance of the system. The number of iterations is specified a priori instead of a norm-based exit criterion, and collective communications are avoided. The overall algorithm thus involves only point-to-point communication between neighboring processors. Our implementation of the tridiagonal solver differs from and avoids the drawbacks of past efforts in the following ways: it introduces no parallelization-related approximations (multiprocessor solutions are exactly identical to uniprocessor ones), it involves minimal communication, the mathematical complexity is similar to that of the Thomas algorithm on a single processor, and it does not require any communication and computation scheduling.

Scalable manufacturing of biomimetic moldable hydrogels for industrial applications

Science.gov (United States)

Yu, Anthony C.; Chen, Haoxuan; Chan, Doreen; Agmon, Gillie; Stapleton, Lyndsay M.; Sevit, Alex M.; Tibbitt, Mark W.; Acosta, Jesse D.; Zhang, Tony; Franzia, Paul W.; Langer, Robert; Appel, Eric A.

2016-12-01

Hydrogels are a class of soft material that is exploited in many, often completely disparate, industrial applications, on account of their unique and tunable properties. Advances in soft material design are yielding next-generation moldable hydrogels that address engineering criteria in several industrial settings such as complex viscosity modifiers, hydraulic or injection fluids, and sprayable carriers. Industrial implementation of these viscoelastic materials requires extreme volumes of material, upwards of several hundred million gallons per year. Here, we demonstrate a paradigm for the scalable fabrication of self-assembled moldable hydrogels using rationally engineered, biomimetic polymer-nanoparticle interactions. Cellulose derivatives are linked together by selective adsorption to silica nanoparticles via dynamic and multivalent interactions. We show that the self-assembly process for gel formation is easily scaled in a linear fashion from 0.5 mL to over 15 L without alteration of the mechanical properties of the resultant materials. The facile and scalable preparation of these materials leveraging self-assembly of inexpensive, renewable, and environmentally benign starting materials, coupled with the tunability of their properties, make them amenable to a range of industrial applications. In particular, we demonstrate their utility as injectable materials for pipeline maintenance and product recovery in industrial food manufacturing as well as their use as sprayable carriers for robust application of fire retardants in preventing wildland fires.

Performance-scalable volumetric data classification for online industrial inspection

Science.gov (United States)

Abraham, Aby J.; Sadki, Mustapha; Lea, R. M.

2002-03-01

Non-intrusive inspection and non-destructive testing of manufactured objects with complex internal structures typically requires the enhancement, analysis and visualization of high-resolution volumetric data. Given the increasing availability of fast 3D scanning technology (e.g. cone-beam CT), enabling on-line detection and accurate discrimination of components or sub-structures, the inherent complexity of classification algorithms inevitably leads to throughput bottlenecks. Indeed, whereas typical inspection throughput requirements range from 1 to 1000 volumes per hour, depending on density and resolution, current computational capability is one to two orders-of-magnitude less. Accordingly, speeding up classification algorithms requires both reduction of algorithm complexity and acceleration of computer performance. A shape-based classification algorithm, offering algorithm complexity reduction, by using ellipses as generic descriptors of solids-of-revolution, and supporting performance-scalability, by exploiting the inherent parallelism of volumetric data, is presented. A two-stage variant of the classical Hough transform is used for ellipse detection and correlation of the detected ellipses facilitates position-, scale- and orientation-invariant component classification. Performance-scalability is achieved cost-effectively by accelerating a PC host with one or more COTS (Commercial-Off-The-Shelf) PCI multiprocessor cards. Experimental results are reported to demonstrate the feasibility and cost-effectiveness of the data-parallel classification algorithm for on-line industrial inspection applications.

Fourier transform based scalable image quality measure.

Science.gov (United States)

Narwaria, Manish; Lin, Weisi; McLoughlin, Ian; Emmanuel, Sabu; Chia, Liang-Tien

2012-08-01

We present a new image quality assessment (IQA) algorithm based on the phase and magnitude of the 2D (twodimensional) Discrete Fourier Transform (DFT). The basic idea is to compare the phase and magnitude of the reference and distorted images to compute the quality score. However, it is well known that the Human Visual Systems (HVSs) sensitivity to different frequency components is not the same. We accommodate this fact via a simple yet effective strategy of nonuniform binning of the frequency components. This process also leads to reduced space representation of the image thereby enabling the reduced-reference (RR) prospects of the proposed scheme. We employ linear regression to integrate the effects of the changes in phase and magnitude. In this way, the required weights are determined via proper training and hence more convincing and effective. Lastly, using the fact that phase usually conveys more information than magnitude, we use only the phase for RR quality assessment. This provides the crucial advantage of further reduction in the required amount of reference image information. The proposed method is therefore further scalable for RR scenarios. We report extensive experimental results using a total of 9 publicly available databases: 7 image (with a total of 3832 distorted images with diverse distortions) and 2 video databases (totally 228 distorted videos). These show that the proposed method is overall better than several of the existing fullreference (FR) algorithms and two RR algorithms. Additionally, there is a graceful degradation in prediction performance as the amount of reference image information is reduced thereby confirming its scalability prospects. To enable comparisons and future study, a Matlab implementation of the proposed algorithm is available at http://www.ntu.edu.sg/home/wslin/reduced_phase.rar.

The Political Economy of E-Learning Educational Development Strategies, Standardisation and Scalability

Science.gov (United States)

Kenney, Jacqueline; Hermens, Antoine; Clarke, Thomas

2004-01-01

The development of e-learning by government through policy, funding allocations, research-based collaborative projects and alliances has increased recently in both developed and under-developed nations. The paper notes that government, industry and corporate users are increasingly focusing on standardisation issues and the scalability of…

Enabling Highly-Scalable Remote Memory Access Programming with MPI-3 One Sided

Directory of Open Access Journals (Sweden)

Robert Gerstenberger

2014-01-01

Full Text Available Modern interconnects offer remote direct memory access (RDMA features. Yet, most applications rely on explicit message passing for communications albeit their unwanted overheads. The MPI-3.0 standard defines a programming interface for exploiting RDMA networks directly, however, it's scalability and practicability has to be demonstrated in practice. In this work, we develop scalable bufferless protocols that implement the MPI-3.0 specification. Our protocols support scaling to millions of cores with negligible memory consumption while providing highest performance and minimal overheads. To arm programmers, we provide a spectrum of performance models for all critical functions and demonstrate the usability of our library and models with several application studies with up to half a million processes. We show that our design is comparable to, or better than UPC and Fortran Coarrays in terms of latency, bandwidth and message rate. We also demonstrate application performance improvements with comparable programming complexity.

A graph algebra for scalable visual analytics.

Science.gov (United States)

Shaverdian, Anna A; Zhou, Hao; Michailidis, George; Jagadish, Hosagrahar V

2012-01-01

Visual analytics (VA), which combines analytical techniques with advanced visualization features, is fast becoming a standard tool for extracting information from graph data. Researchers have developed many tools for this purpose, suggesting a need for formal methods to guide these tools' creation. Increased data demands on computing requires redesigning VA tools to consider performance and reliability in the context of analysis of exascale datasets. Furthermore, visual analysts need a way to document their analyses for reuse and results justification. A VA graph framework encapsulated in a graph algebra helps address these needs. Its atomic operators include selection and aggregation. The framework employs a visual operator and supports dynamic attributes of data to enable scalable visual exploration of data.

A Scalable Heuristic for Viral Marketing Under the Tipping Model

Science.gov (United States)

2013-09-01

Flixster is a social media website that allows users to share reviews and other information about cinema . [35] It was extracted in Dec. 2010. – FourSquare...work of Reichman were developed independently . We also note that Reichman performs no experimental evaluation of the algorithm. A Scalable Heuristic...other dif- fusion models, such as the independent cascade model [21] and evolutionary graph theory [25] as well as probabilistic variants of the

Robust and scalable optical one-way quantum computation

International Nuclear Information System (INIS)

Wang Hefeng; Yang Chuiping; Nori, Franco

2010-01-01

We propose an efficient approach for deterministically generating scalable cluster states with photons. This approach involves unitary transformations performed on atoms coupled to optical cavities. Its operation cost scales linearly with the number of qubits in the cluster state, and photon qubits are encoded such that single-qubit operations can be easily implemented by using linear optics. Robust optical one-way quantum computation can be performed since cluster states can be stored in atoms and then transferred to photons that can be easily operated and measured. Therefore, this proposal could help in performing robust large-scale optical one-way quantum computation.

A Scalable Architecture of a Structured LDPC Decoder

Science.gov (United States)

Lee, Jason Kwok-San; Lee, Benjamin; Thorpe, Jeremy; Andrews, Kenneth; Dolinar, Sam; Hamkins, Jon

2004-01-01

We present a scalable decoding architecture for a certain class of structured LDPC codes. The codes are designed using a small (n,r) protograph that is replicated Z times to produce a decoding graph for a (Z x n, Z x r) code. Using this architecture, we have implemented a decoder for a (4096,2048) LDPC code on a Xilinx Virtex-II 2000 FPGA, and achieved decoding speeds of 31 Mbps with 10 fixed iterations. The implemented message-passing algorithm uses an optimized 3-bit non-uniform quantizer that operates with 0.2dB implementation loss relative to a floating point decoder.

Scalable error correction in distributed ion trap computers

International Nuclear Information System (INIS)

Oi, Daniel K. L.; Devitt, Simon J.; Hollenberg, Lloyd C. L.

2006-01-01

A major challenge for quantum computation in ion trap systems is scalable integration of error correction and fault tolerance. We analyze a distributed architecture with rapid high-fidelity local control within nodes and entangled links between nodes alleviating long-distance transport. We demonstrate fault-tolerant operator measurements which are used for error correction and nonlocal gates. This scheme is readily applied to linear ion traps which cannot be scaled up beyond a few ions per individual trap but which have access to a probabilistic entanglement mechanism. A proof-of-concept system is presented which is within the reach of current experiment

Scalable Brain Network Construction on White Matter Fibers.

Science.gov (United States)

Chung, Moo K; Adluru, Nagesh; Dalton, Kim M; Alexander, Andrew L; Davidson, Richard J

2011-02-12

DTI offers a unique opportunity to characterize the structural connectivity of the human brain non-invasively by tracing white matter fiber tracts. Whole brain tractography studies routinely generate up to half million tracts per brain, which serves as edges in an extremely large 3D graph with up to half million edges. Currently there is no agreed-upon method for constructing the brain structural network graphs out of large number of white matter tracts. In this paper, we present a scalable iterative framework called the ε-neighbor method for building a network graph and apply it to testing abnormal connectivity in autism.

Scalable and Resilient Middleware to Handle Information Exchange during Environment Crisis

Science.gov (United States)

Tao, R.; Poslad, S.; Moßgraber, J.; Middleton, S.; Hammitzsch, M.

2012-04-01

The EU FP7 TRIDEC project focuses on enabling real-time, intelligent, information management of collaborative, complex, critical decision processes for earth management. A key challenge is to promote a communication infrastructure to facilitate interoperable environment information services during environment events and crises such as tsunamis and drilling, during which increasing volumes and dimensionality of disparate information sources, including sensor-based and human-based ones, can result, and need to be managed. Such a system needs to support: scalable, distributed messaging; asynchronous messaging; open messaging to handling changing clients such as new and retired automated system and human information sources becoming online or offline; flexible data filtering, and heterogeneous access networks (e.g., GSM, WLAN and LAN). In addition, the system needs to be resilient to handle the ICT system failures, e.g. failure, degradation and overloads, during environment events. There are several system middleware choices for TRIDEC based upon a Service-oriented-architecture (SOA), Event-driven-Architecture (EDA), Cloud Computing, and Enterprise Service Bus (ESB). In an SOA, everything is a service (e.g. data access, processing and exchange); clients can request on demand or subscribe to services registered by providers; more often interaction is synchronous. In an EDA system, events that represent significant changes in state can be processed simply, or as streams or more complexly. Cloud computing is a virtualization, interoperable and elastic resource allocation model. An ESB, a fundamental component for enterprise messaging, supports synchronous and asynchronous message exchange models and has inbuilt resilience against ICT failure. Our middleware proposal is an ESB based hybrid architecture model: an SOA extension supports more synchronous workflows; EDA assists the ESB to handle more complex event processing; Cloud computing can be used to increase and

NASA Airborne Astronomy Ambassadors (AAA) Professional Development and NASA Connections

Science.gov (United States)

Backman, D. E.; Clark, C.; Harman, P. K.

2017-12-01

NASA's Airborne Astronomy Ambassadors (AAA) program is a three-part professional development (PD) experience for high school physics, astronomy, and earth science teachers. AAA PD consists of: (1) blended learning via webinars, asynchronous content learning, and in-person workshops, (2) a STEM immersion experience at NASA Armstrong's B703 science research aircraft facility in Palmdale, California, and (3) ongoing opportunities for connection with NASA astrophysics and planetary science Subject Matter Experts (SMEs). AAA implementation in 2016-18 involves partnerships between the SETI Institute and seven school districts in northern and southern California. AAAs in the current cohort were selected by the school districts based on criteria developed by AAA program staff working with WestEd evaluation consultants. The selected teachers were then randomly assigned by WestEd to a Group A or B to support controlled testing of student learning. Group A completed their PD during January - August 2017, then participated in NASA SOFIA science flights during fall 2017. Group B will act as a control during the 2017-18 school year, then will complete their professional development and SOFIA flights during 2018. A two-week AAA electromagnetic spectrum and multi-wavelength astronomy curriculum aligned with the Science Framework for California Public Schools and Next Generation Science Standards was developed by program staff for classroom delivery. The curriculum (as well as the AAA's pre-flight PD) capitalizes on NASA content by using "science snapshot" case studies regarding astronomy research conducted by SOFIA. AAAs also interact with NASA SMEs during flight weeks and will translate that interaction into classroom content. The AAA program will make controlled measurements of student gains in standards-based learning plus changes in student attitudes towards STEM, and observe & record the AAAs' implementation of curricular changes. Funded by NASA: NNX16AC51

Scalability Modeling for Optimal Provisioning of Data Centers in Telenor: A better balance between under- and over-provisioning

OpenAIRE

Rygg, Knut Helge

2012-01-01

The scalability of an information system describes the relationship between system ca-pacity and system size. This report studies the scalability of Microsoft Lync Server 2010 in order to provide guidelines for provisioning hardware resources. Optimal pro-visioning is required to reduce both deployment and operational costs, while keeping an acceptable service quality.All Lync servers in the test setup are virtualizedusingVMware ESXi 5.0 and the system runs on a Cisco Unified Computing System...

Through the Eyes of NASA: NASA's 2017 Eclipse Education Progam

Science.gov (United States)

Mayo, L.

2017-12-01

Over the last three years, NASA has been developing plans to bring the August 21st total solar eclipse to the nation, "as only NASA can", leveraging its considerable space assets, technology, scientists, and its unmatched commitment to science education. The eclipse, long anticipated by many groups, represents the largest Big Event education program that NASA has ever undertaken. It is the latest in a long string of successful Big Event international celebrations going back two decades including both transits of Venus, three solar eclipses, solar maximum, and mission events such as the MSL/Curiosity landing on Mars, and the launch of the Lunar Reconnaissance Orbiter (LRO) to name a few. This talk will detail NASA's program development methods, strategic partnerships, and strategies for using this celestial event to engage the nation and improve overall science literacy.

A scalable variational inequality approach for flow through porous media models with pressure-dependent viscosity

Science.gov (United States)

Mapakshi, N. K.; Chang, J.; Nakshatrala, K. B.

2018-04-01

Mathematical models for flow through porous media typically enjoy the so-called maximum principles, which place bounds on the pressure field. It is highly desirable to preserve these bounds on the pressure field in predictive numerical simulations, that is, one needs to satisfy discrete maximum principles (DMP). Unfortunately, many of the existing formulations for flow through porous media models do not satisfy DMP. This paper presents a robust, scalable numerical formulation based on variational inequalities (VI), to model non-linear flows through heterogeneous, anisotropic porous media without violating DMP. VI is an optimization technique that places bounds on the numerical solutions of partial differential equations. To crystallize the ideas, a modification to Darcy equations by taking into account pressure-dependent viscosity will be discretized using the lowest-order Raviart-Thomas (RT0) and Variational Multi-scale (VMS) finite element formulations. It will be shown that these formulations violate DMP, and, in fact, these violations increase with an increase in anisotropy. It will be shown that the proposed VI-based formulation provides a viable route to enforce DMP. Moreover, it will be shown that the proposed formulation is scalable, and can work with any numerical discretization and weak form. A series of numerical benchmark problems are solved to demonstrate the effects of heterogeneity, anisotropy and non-linearity on DMP violations under the two chosen formulations (RT0 and VMS), and that of non-linearity on solver convergence for the proposed VI-based formulation. Parallel scalability on modern computational platforms will be illustrated through strong-scaling studies, which will prove the efficiency of the proposed formulation in a parallel setting. Algorithmic scalability as the problem size is scaled up will be demonstrated through novel static-scaling studies. The performed static-scaling studies can serve as a guide for users to be able to select

NASA Earthdata Forums: An Interactive Venue for Discussions of NASA Data and Earth Science

Science.gov (United States)

Hearty, Thomas J., III; Acker, James; Meyer, Dave; Northup, Emily A.; Bagwell, Ross E.

2017-01-01

We demonstrate how students and teachers can register to use the NASA Earthdata Forums. The NASA Earthdata forums provide a venue where registered users can pose questions regarding NASA Earth science data in a moderated forum, and have their questions answered by data experts and scientific subject matter experts connected with NASA Earth science missions and projects. Since the forums are also available for research scientists to pose questions and discuss pertinent topics, the NASA Earthdata Forums provide a unique opportunity for students and teachers to gain insight from expert scientists and enhance their knowledge of the many different ways that NASA Earth observations can be used in research and applications.

Differentiation of Human Pluripotent Stem Cells into Functional Endothelial Cells in Scalable Suspension Culture

Directory of Open Access Journals (Sweden)

Ruth Olmer

2018-05-01

Full Text Available Summary: Endothelial cells (ECs are involved in a variety of cellular responses. As multifunctional components of vascular structures, endothelial (progenitor cells have been utilized in cellular therapies and are required as an important cellular component of engineered tissue constructs and in vitro disease models. Although primary ECs from different sources are readily isolated and expanded, cell quantity and quality in terms of functionality and karyotype stability is limited. ECs derived from human induced pluripotent stem cells (hiPSCs represent an alternative and potentially superior cell source, but traditional culture approaches and 2D differentiation protocols hardly allow for production of large cell numbers. Aiming at the production of ECs, we have developed a robust approach for efficient endothelial differentiation of hiPSCs in scalable suspension culture. The established protocol results in relevant numbers of ECs for regenerative approaches and industrial applications that show in vitro proliferation capacity and a high degree of chromosomal stability. : In this article, U. Martin and colleagues show the generation of hiPSC endothelial cells in scalable cultures in up to 100 mL culture volume. The generated ECs show in vitro proliferation capacity and a high degree of chromosomal stability after in vitro expansion. The established protocol allows to generate hiPSC-derived ECs in relevant numbers for regenerative approaches. Keywords: hiPSC differentiation, endothelial cells, scalable culture

Scalable conditional induction variables (CIV) analysis

DEFF Research Database (Denmark)

Oancea, Cosmin Eugen; Rauchwerger, Lawrence

2015-01-01

parallelizing compiler and evaluated its impact on five Fortran benchmarks. We have found that that there are many important loops using CIV subscripts and that our analysis can lead to their scalable parallelization. This in turn has led to the parallelization of the benchmark programs they appear in.......Subscripts using induction variables that cannot be expressed as a formula in terms of the enclosing-loop indices appear in the low-level implementation of common programming abstractions such as filter, or stack operations and pose significant challenges to automatic parallelization. Because...... the complexity of such induction variables is often due to their conditional evaluation across the iteration space of loops we name them Conditional Induction Variables (CIV). This paper presents a flow-sensitive technique that summarizes both such CIV-based and affine subscripts to program level, using the same...

The Node Monitoring Component of a Scalable Systems Software Environment

Energy Technology Data Exchange (ETDEWEB)

Miller, Samuel James [Iowa State Univ., Ames, IA (United States)

2006-01-01

This research describes Fountain, a suite of programs used to monitor the resources of a cluster. A cluster is a collection of individual computers that are connected via a high speed communication network. They are traditionally used by users who desire more resources, such as processing power and memory, than any single computer can provide. A common drawback to effectively utilizing such a large-scale system is the management infrastructure, which often does not often scale well as the system grows. Large-scale parallel systems provide new research challenges in the area of systems software, the programs or tools that manage the system from boot-up to running a parallel job. The approach presented in this thesis utilizes a collection of separate components that communicate with each other to achieve a common goal. While systems software comprises a broad array of components, this thesis focuses on the design choices for a node monitoring component. We will describe Fountain, an implementation of the Scalable Systems Software (SSS) node monitor specification. It is targeted at aggregate node monitoring for clusters, focusing on both scalability and fault tolerance as its design goals. It leverages widely used technologies such as XML and HTTP to present an interface to other components in the SSS environment.

NASA EEE Parts and NASA Electronic Parts and Packaging (NEPP) Program Update 2018

Science.gov (United States)

Label, Kenneth A.; Sampson, Michael J.; Pellish, Jonathan A.; Majewicz, Peter J.

2018-01-01

NASA Electronic Parts and Packaging (NEPP) Program and NASA Electronic Parts Assurance Group (NEPAG) are NASAs point-of-contacts for reliability and radiation tolerance of EEE parts and their packages. This presentation includes an FY18 program overview.

NASA Parts Selection List (NPSL) WWW Site http://nepp.nasa.gov/npsl

Science.gov (United States)

Brusse, Jay

2000-01-01

The NASA Parts Selection List (NPSL) is an on-line resource for electronic parts selection tailored for use by spaceflight projects. The NPSL provides a list of commonly used electronic parts that have a history of satisfactory use in spaceflight applications. The objective of this www site is to provide NASA projects, contractors, university experimenters, et al with an easy to use resource that provides a baseline of electronic parts from which designers are encouraged to select. The NPSL is an ongoing resource produced by Code 562 in support of the NASA HQ funded NASA Electronic Parts and Packaging (NEPP) Program. The NPSL is produced as an electronic format deliverable made available via the referenced www site administered by Code 562. The NPSL does not provide information pertaining to patented or proprietary information. All of the information contained in the NPSL is available through various other public domain resources such as US Military procurement specifications for electronic parts, NASA GSFC's Preferred Parts List (PPL-21), and NASA's Standard Parts List (MIL-STD975).

NASA Accountability Report

Science.gov (United States)

1997-01-01

NASA is piloting fiscal year (FY) 1997 Accountability Reports, which streamline and upgrade reporting to Congress and the public. The document presents statements by the NASA administrator, and the Chief Financial Officer, followed by an overview of NASA's organizational structure and the planning and budgeting process. The performance of NASA in four strategic enterprises is reviewed: (1) Space Science, (2) Mission to Planet Earth, (3) Human Exploration and Development of Space, and (4) Aeronautics and Space Transportation Technology. Those areas which support the strategic enterprises are also reviewed in a section called Crosscutting Processes. For each of the four enterprises, there is discussion about the long term goals, the short term objectives and the accomplishments during FY 1997. The Crosscutting Processes section reviews issues and accomplishments relating to human resources, procurement, information technology, physical resources, financial management, small and disadvantaged businesses, and policy and plans. Following the discussion about the individual areas is Management's Discussion and Analysis, about NASA's financial statements. This is followed by a report by an independent commercial auditor and the financial statements.

Fast and Scalable Computation of the Forward and Inverse Discrete Periodic Radon Transform.

Science.gov (United States)

Carranza, Cesar; Llamocca, Daniel; Pattichis, Marios

2016-01-01

The discrete periodic radon transform (DPRT) has extensively been used in applications that involve image reconstructions from projections. Beyond classic applications, the DPRT can also be used to compute fast convolutions that avoids the use of floating-point arithmetic associated with the use of the fast Fourier transform. Unfortunately, the use of the DPRT has been limited by the need to compute a large number of additions and the need for a large number of memory accesses. This paper introduces a fast and scalable approach for computing the forward and inverse DPRT that is based on the use of: a parallel array of fixed-point adder trees; circular shift registers to remove the need for accessing external memory components when selecting the input data for the adder trees; an image block-based approach to DPRT computation that can fit the proposed architecture to available resources; and fast transpositions that are computed in one or a few clock cycles that do not depend on the size of the input image. As a result, for an N × N image (N prime), the proposed approach can compute up to N(2) additions per clock cycle. Compared with the previous approaches, the scalable approach provides the fastest known implementations for different amounts of computational resources. For example, for a 251×251 image, for approximately 25% fewer flip-flops than required for a systolic implementation, we have that the scalable DPRT is computed 36 times faster. For the fastest case, we introduce optimized just 2N + ⌈log(2) N⌉ + 1 and 2N + 3 ⌈log(2) N⌉ + B + 2 cycles, architectures that can compute the DPRT and its inverse in respectively, where B is the number of bits used to represent each input pixel. On the other hand, the scalable DPRT approach requires more 1-b additions than for the systolic implementation and provides a tradeoff between speed and additional 1-b additions. All of the proposed DPRT architectures were implemented in VHSIC Hardware Description Language

NASA Technology Plan 1998

Science.gov (United States)

1998-01-01

This NASA Strategic Plan describes an ambitious, exciting vision for the Agency across all its Strategic Enterprises that addresses a series of fundamental questions of science and research. This vision is so challenging that it literally depends on the success of an aggressive, cutting-edge advanced technology development program. The objective of this plan is to describe the NASA-wide technology program in a manner that provides not only the content of ongoing and planned activities, but also the rationale and justification for these activities in the context of NASA's future needs. The scope of this plan is Agencywide, and it includes technology investments to support all major space and aeronautics program areas, but particular emphasis is placed on longer term strategic technology efforts that will have broad impact across the spectrum of NASA activities and perhaps beyond. Our goal is to broaden the understanding of NASA technology programs and to encourage greater participation from outside the Agency. By relating technology goals to anticipated mission needs, we hope to stimulate additional innovative approaches to technology challenges and promote more cooperative programs with partners outside NASA who share common goals. We also believe that this will increase the transfer of NASA-sponsored technology into nonaerospace applications, resulting in an even greater return on the investment in NASA.

Epitaxial Growth of Two-Dimensional Layered Transition-Metal Dichalcogenides: Growth Mechanism, Controllability, and Scalability

KAUST Repository

Li, Henan; Li, Ying; Aljarb, Areej; Shi, Yumeng; Li, Lain-Jong

2017-01-01

to generate high-quality TMDC layers with scalable size, controllable thickness, and excellent electronic properties suitable for both technological applications and fundamental sciences. The capability to precisely engineer 2D materials by chemical approaches

NASA Information Technology Implementation Plan

Science.gov (United States)

2000-01-01

NASA's Information Technology (IT) resources and IT support continue to be a growing and integral part of all NASA missions. Furthermore, the growing IT support requirements are becoming more complex and diverse. The following are a few examples of the growing complexity and diversity of NASA's IT environment. NASA is conducting basic IT research in the Intelligent Synthesis Environment (ISE) and Intelligent Systems (IS) Initiatives. IT security, infrastructure protection, and privacy of data are requiring more and more management attention and an increasing share of the NASA IT budget. Outsourcing of IT support is becoming a key element of NASA's IT strategy as exemplified by Outsourcing Desktop Initiative for NASA (ODIN) and the outsourcing of NASA Integrated Services Network (NISN) support. Finally, technology refresh is helping to provide improved support at lower cost. Recently the NASA Automated Data Processing (ADP) Consolidation Center (NACC) upgraded its bipolar technology computer systems with Complementary Metal Oxide Semiconductor (CMOS) technology systems. This NACC upgrade substantially reduced the hardware maintenance and software licensing costs, significantly increased system speed and capacity, and reduced customer processing costs by 11 percent.

Towards Scalable Entangled Photon Sources with Self-Assembled InAs /GaAs Quantum Dots

Science.gov (United States)

Wang, Jianping; Gong, Ming; Guo, G.-C.; He, Lixin

2015-08-01

The biexciton cascade process in self-assembled quantum dots (QDs) provides an ideal system for realizing deterministic entangled photon-pair sources, which are essential to quantum information science. The entangled photon pairs have recently been generated in experiments after eliminating the fine-structure splitting (FSS) of excitons using a number of different methods. Thus far, however, QD-based sources of entangled photons have not been scalable because the wavelengths of QDs differ from dot to dot. Here, we propose a wavelength-tunable entangled photon emitter mounted on a three-dimensional stressor, in which the FSS and exciton energy can be tuned independently, thereby enabling photon entanglement between dissimilar QDs. We confirm these results via atomistic pseudopotential calculations. This provides a first step towards future realization of scalable entangled photon generators for quantum information applications.

Palacios and Kitten : high performance operating systems for scalable virtualized and native supercomputing.

Energy Technology Data Exchange (ETDEWEB)

Widener, Patrick (University of New Mexico); Jaconette, Steven (Northwestern University); Bridges, Patrick G. (University of New Mexico); Xia, Lei (Northwestern University); Dinda, Peter (Northwestern University); Cui, Zheng.; Lange, John (Northwestern University); Hudson, Trammell B.; Levenhagen, Michael J.; Pedretti, Kevin Thomas Tauke; Brightwell, Ronald Brian

2009-09-01

Palacios and Kitten are new open source tools that enable applications, whether ported or not, to achieve scalable high performance on large machines. They provide a thin layer over the hardware to support both full-featured virtualized environments and native code bases. Kitten is an OS under development at Sandia that implements a lightweight kernel architecture to provide predictable behavior and increased flexibility on large machines, while also providing Linux binary compatibility. Palacios is a VMM that is under development at Northwestern University and the University of New Mexico. Palacios, which can be embedded into Kitten and other OSes, supports existing, unmodified applications and operating systems by using virtualization that leverages hardware technologies. We describe the design and implementation of both Kitten and Palacios. Our benchmarks show that they provide near native, scalable performance. Palacios and Kitten provide an incremental path to using supercomputer resources that is not performance-compromised.

NASA's Big Data Task Force

Science.gov (United States)

Holmes, C. P.; Kinter, J. L.; Beebe, R. F.; Feigelson, E.; Hurlburt, N. E.; Mentzel, C.; Smith, G.; Tino, C.; Walker, R. J.

2017-12-01

Two years ago NASA established the Ad Hoc Big Data Task Force (BDTF - https://science.nasa.gov/science-committee/subcommittees/big-data-task-force), an advisory working group with the NASA Advisory Council system. The scope of the Task Force included all NASA Big Data programs, projects, missions, and activities. The Task Force focused on such topics as exploring the existing and planned evolution of NASA's science data cyber-infrastructure that supports broad access to data repositories for NASA Science Mission Directorate missions; best practices within NASA, other Federal agencies, private industry and research institutions; and Federal initiatives related to big data and data access. The BDTF has completed its two-year term and produced several recommendations plus four white papers for NASA's Science Mission Directorate. This presentation will discuss the activities and results of the TF including summaries of key points from its focused study topics. The paper serves as an introduction to the papers following in this ESSI session.

Space-Filling Supercapacitor Carpets: Highly scalable fractal architecture for energy storage

Science.gov (United States)

Tiliakos, Athanasios; Trefilov, Alexandra M. I.; Tanasǎ, Eugenia; Balan, Adriana; Stamatin, Ioan

2018-04-01

Revamping ground-breaking ideas from fractal geometry, we propose an alternative micro-supercapacitor configuration realized by laser-induced graphene (LIG) foams produced via laser pyrolysis of inexpensive commercial polymers. The Space-Filling Supercapacitor Carpet (SFSC) architecture introduces the concept of nested electrodes based on the pre-fractal Peano space-filling curve, arranged in a symmetrical equilateral setup that incorporates multiple parallel capacitor cells sharing common electrodes for maximum efficiency and optimal length-to-area distribution. We elucidate on the theoretical foundations of the SFSC architecture, and we introduce innovations (high-resolution vector-mode printing) in the LIG method that allow for the realization of flexible and scalable devices based on low iterations of the Peano algorithm. SFSCs exhibit distributed capacitance properties, leading to capacitance, energy, and power ratings proportional to the number of nested electrodes (up to 4.3 mF, 0.4 μWh, and 0.2 mW for the largest tested model of low iteration using aqueous electrolytes), with competitively high energy and power densities. This can pave the road for full scalability in energy storage, reaching beyond the scale of micro-supercapacitors for incorporating into larger and more demanding applications.

The scalable coherent interface, IEEE P1596

International Nuclear Information System (INIS)

Gustavson, D.B.

1990-01-01

IEEE P1596, the scalable coherent interface (formerly known as SuperBus) is based on experience gained while developing Fastbus (ANSI/IEEE 960--1986, IEC 935), Futurebus (IEEE P896.x) and other modern 32-bit buses. SCI goals include a minimum bandwidth of 1 GByte/sec per processor in multiprocessor systems with thousands of processors; efficient support of a coherent distributed-cache image of distributed shared memory; support for repeaters which interface to existing or future buses; and support for inexpensive small rings as well as for general switched interconnections like Banyan, Omega, or crossbar networks. This paper presents a summary of current directions, reports the status of the work in progress, and suggests some applications in data acquisition and physics

A lightweight scalable agarose-gel-synthesized thermoelectric composite

Science.gov (United States)

Kim, Jin Ho; Fernandes, Gustavo E.; Lee, Do-Joong; Hirst, Elizabeth S.; Osgood, Richard M., III; Xu, Jimmy

2018-03-01

Electronic devices are now advancing beyond classical, rigid systems and moving into lighweight flexible regimes, enabling new applications such as body-wearables and ‘e-textiles’. To support this new electronic platform, composite materials that are highly conductive yet scalable, flexible, and wearable are needed. Materials with high electrical conductivity often have poor thermoelectric properties because their thermal transport is made greater by the same factors as their electronic conductivity. We demonstrate, in proof-of-principle experiments, that a novel binary composite can disrupt thermal (phononic) transport, while maintaining high electrical conductivity, thus yielding promising thermoelectric properties. Highly conductive Multi-Wall Carbon Nanotube (MWCNT) composites are combined with a low-band gap semiconductor, PbS. The work functions of the two materials are closely matched, minimizing the electrical contact resistance within the composite. Disparities in the speed of sound in MWCNTs and PbS help to inhibit phonon propagation, and boundary layer scattering at interfaces between these two materials lead to large Seebeck coefficient (> 150 μV/K) (Mott N F and Davis E A 1971 Electronic Processes in Non-crystalline Materials (Oxford: Clarendon), p 47) and a power factor as high as 10 μW/(K2 m). The overall fabrication process is not only scalable but also conformal and compatible with large-area flexible hosts including metal sheets, films, coatings, possibly arrays of fibers, textiles and fabrics. We explain the behavior of this novel thermoelectric material platform in terms of differing length scales for electrical conductivity and phononic heat transfer, and explore new material configurations for potentially lightweight and flexible thermoelectric devices that could be networked in a textile.

fastBMA: scalable network inference and transitive reduction.

Science.gov (United States)

Hung, Ling-Hong; Shi, Kaiyuan; Wu, Migao; Young, William Chad; Raftery, Adrian E; Yeung, Ka Yee

2017-10-01

Inferring genetic networks from genome-wide expression data is extremely demanding computationally. We have developed fastBMA, a distributed, parallel, and scalable implementation of Bayesian model averaging (BMA) for this purpose. fastBMA also includes a computationally efficient module for eliminating redundant indirect edges in the network by mapping the transitive reduction to an easily solved shortest-path problem. We evaluated the performance of fastBMA on synthetic data and experimental genome-wide time series yeast and human datasets. When using a single CPU core, fastBMA is up to 100 times faster than the next fastest method, LASSO, with increased accuracy. It is a memory-efficient, parallel, and distributed application that scales to human genome-wide expression data. A 10 000-gene regulation network can be obtained in a matter of hours using a 32-core cloud cluster (2 nodes of 16 cores). fastBMA is a significant improvement over its predecessor ScanBMA. It is more accurate and orders of magnitude faster than other fast network inference methods such as the 1 based on LASSO. The improved scalability allows it to calculate networks from genome scale data in a reasonable time frame. The transitive reduction method can improve accuracy in denser networks. fastBMA is available as code (M.I.T. license) from GitHub (https://github.com/lhhunghimself/fastBMA), as part of the updated networkBMA Bioconductor package (https://www.bioconductor.org/packages/release/bioc/html/networkBMA.html) and as ready-to-deploy Docker images (https://hub.docker.com/r/biodepot/fastbma/). © The Authors 2017. Published by Oxford University Press.

Conscientiousness at the workplace: Applying mixture IRT to investigate scalability and predictive validity

NARCIS (Netherlands)

Egberink, I.J.L.; Meijer, R.R.; Veldkamp, Bernard P.

2010-01-01

Mixture item response theory (IRT) models have been used to assess multidimensionality of the construct being measured and to detect different response styles for different groups. In this study a mixture version of the graded response model was applied to investigate scalability and predictive

Conscientiousness in the workplace : Applying mixture IRT to investigate scalability and predictive validity

NARCIS (Netherlands)

Egberink, I.J.L.; Meijer, R.R.; Veldkamp, B.P.

Mixture item response theory (IRT) models have been used to assess multidimensionality of the construct being measured and to detect different response styles for different groups. In this study a mixture version of the graded response model was applied to investigate scalability and predictive

A scalable lock-free hash table with open addressing

DEFF Research Database (Denmark)

Nielsen, Jesper Puge; Karlsson, Sven

2016-01-01

and concurrent operations without any locks. In this paper, we present a new fully lock-free open addressed hash table with a simpler design than prior published work. We split hash table insertions into two atomic phases: first inserting a value ignoring other concurrent operations, then in the second phase......Concurrent data structures synchronized with locks do not scale well with the number of threads. As more scalable alternatives, concurrent data structures and algorithms based on widely available, however advanced, atomic operations have been proposed. These data structures allow for correct...

pcircle - A Suite of Scalable Parallel File System Tools

Energy Technology Data Exchange (ETDEWEB)

2015-10-01

Most of the software related to file system are written for conventional local file system, they are serialized and can't take advantage of the benefit of a large scale parallel file system. "pcircle" software builds on top of ubiquitous MPI in cluster computing environment and "work-stealing" pattern to provide a scalable, high-performance suite of file system tools. In particular - it implemented parallel data copy and parallel data checksumming, with advanced features such as async progress report, checkpoint and restart, as well as integrity checking.

A scalable parallel algorithm for multiple objective linear programs

Science.gov (United States)

Wiecek, Malgorzata M.; Zhang, Hong

1994-01-01

This paper presents an ADBASE-based parallel algorithm for solving multiple objective linear programs (MOLP's). Job balance, speedup and scalability are of primary interest in evaluating efficiency of the new algorithm. Implementation results on Intel iPSC/2 and Paragon multiprocessors show that the algorithm significantly speeds up the process of solving MOLP's, which is understood as generating all or some efficient extreme points and unbounded efficient edges. The algorithm gives specially good results for large and very large problems. Motivation and justification for solving such large MOLP's are also included.

Scalable Electrophysiology in Intact Small Animals with Nanoscale Suspended Electrode Arrays

OpenAIRE

Gonzales, Daniel L.; Badhiwala, Krishna N.; Vercosa, Daniel G.; Avants, Ben W.; Liu, Zheng; Zhong, Weiwei; Robinson, Jacob T.

2017-01-01

Electrical measurements from large populations of animals would help reveal fundamental properties of the nervous system and neurological diseases. Small invertebrates are ideal for these large-scale studies; however, patch-clamp electrophysiology in microscopic animals typically requires low-throughput and invasive dissections. To overcome these limitations, we present nano-SPEARs: suspended electrodes integrated into a scalable microfluidic device. Using this technology, we have made the fi...

Scalable Video Streaming Adaptive to Time-Varying IEEE 802.11 MAC Parameters

Science.gov (United States)

Lee, Kyung-Jun; Suh, Doug-Young; Park, Gwang-Hoon; Huh, Jae-Doo

This letter proposes a QoS control method for video streaming service over wireless networks. Based on statistical analysis, the time-varying MAC parameters highly related to channel condition are selected to predict available bitrate. Adaptive bitrate control of scalably-encoded video guarantees continuity in streaming service even if the channel condition changes abruptly.

A versatile scalable PET processing system

International Nuclear Information System (INIS)

Dong, H.; Weisenberger, A.; McKisson, J.; Wenze, Xi; Cuevas, C.; Wilson, J.; Zukerman, L.

2011-01-01

Positron Emission Tomography (PET) historically has major clinical and preclinical applications in cancerous oncology, neurology, and cardiovascular diseases. Recently, in a new direction, an application specific PET system is being developed at Thomas Jefferson National Accelerator Facility (Jefferson Lab) in collaboration with Duke University, University of Maryland at Baltimore (UMAB), and West Virginia University (WVU) targeted for plant eco-physiology research. The new plant imaging PET system is versatile and scalable such that it could adapt to several plant imaging needs - imaging many important plant organs including leaves, roots, and stems. The mechanical arrangement of the detectors is designed to accommodate the unpredictable and random distribution in space of the plant organs without requiring the plant be disturbed. Prototyping such a system requires a new data acquisition system (DAQ) and data processing system which are adaptable to the requirements of these unique and versatile detectors.

iSIGHT-FD scalability test report.

Energy Technology Data Exchange (ETDEWEB)

Clay, Robert L.; Shneider, Max S.

2008-07-01

The engineering analysis community at Sandia National Laboratories uses a number of internal and commercial software codes and tools, including mesh generators, preprocessors, mesh manipulators, simulation codes, post-processors, and visualization packages. We define an analysis workflow as the execution of an ordered, logical sequence of these tools. Various forms of analysis (and in particular, methodologies that use multiple function evaluations or samples) involve executing parameterized variations of these workflows. As part of the DART project, we are evaluating various commercial workflow management systems, including iSIGHT-FD from Engineous. This report documents the results of a scalability test that was driven by DAKOTA and conducted on a parallel computer (Thunderbird). The purpose of this experiment was to examine the suitability and performance of iSIGHT-FD for large-scale, parameterized analysis workflows. As the results indicate, we found iSIGHT-FD to be suitable for this type of application.

The Concept of Business Model Scalability

DEFF Research Database (Denmark)

Nielsen, Christian; Lund, Morten

2015-01-01

The power of business models lies in their ability to visualize and clarify how firms’ may configure their value creation processes. Among the key aspects of business model thinking are a focus on what the customer values, how this value is best delivered to the customer and how strategic partners...... are leveraged in this value creation, delivery and realization exercise. Central to the mainstream understanding of business models is the value proposition towards the customer and the hypothesis generated is that if the firm delivers to the customer what he/she requires, then there is a good foundation...... for a long-term profitable business. However, the message conveyed in this article is that while providing a good value proposition may help the firm ‘get by’, the really successful businesses of today are those able to reach the sweet-spot of business model scalability. This article introduces and discusses...

Scalable Arbitrated Quantum Signature of Classical Messages with Multi-Signers

International Nuclear Information System (INIS)

Yang Yuguang; Wang Yuan; Teng Yiwei; Chai Haiping; Wen Qiaoyan

2010-01-01

Unconditionally secure signature is an important part of quantum cryptography. Usually, a signature scheme only provides an environment for a single signer. Nevertheless, in real applications, many signers may collaboratively send a message to the verifier and convince the verifier that the message is actually transmitted by them. In this paper, we give a scalable arbitrated signature protocol of classical messages with multi-signers. Its security is analyzed and proved to be secure even with a compromised arbitrator. (general)

Non-damaging and scalable carbon nanotube synthesis on carbon fibres

OpenAIRE

De Luca, H; Anthony, DB; Qian, H; Greenhalgh, E; Bismarck, A; Shaffer, M

2016-01-01

The growth of carbon nanotubes (CNTs) on carbon fibres (CFs) to produce a hierarchical fibre with two differing reinforcement length scales, in this instance nanometre and micrometre respectively, is considered a route to improve current state-of-the-art fibre reinforced composites [1]. The scalable production of carbon nanotube-grafted-carbon fibres (CNT-g-CFs) has been limited due to high temperatures, the use of flammable gases and the requirement of inert conditions for CNT synthesis, whi...

A scalable and continuous-upgradable optical wireless and wired convergent access network.

Science.gov (United States)

Sung, J Y; Cheng, K T; Chow, C W; Yeh, C H; Pan, C-L

2014-06-02

In this work, a scalable and continuous upgradable convergent optical access network is proposed. By using a multi-wavelength coherent comb source and a programmable waveshaper at the central office (CO), optical millimeter-wave (mm-wave) signals of different frequencies (from baseband to > 100 GHz) can be generated. Hence, it provides a scalable and continuous upgradable solution for end-user who needs 60 GHz wireless services now and > 100 GHz wireless services in the future. During the upgrade, user only needs to upgrade their optical networking unit (ONU). A programmable waveshaper is used to select the suitable optical tones with wavelength separation equals to the desired mm-wave frequency; while the CO remains intact. The centralized characteristics of the proposed system can easily add any new service and end-user. The centralized control of the wavelength makes the system more stable. Wired data rate of 17.45 Gb/s and w-band wireless data rate up to 3.36 Gb/s were demonstrated after transmission over 40 km of single-mode fiber (SMF).

Scalability of Several Asynchronous Many-Task Models for In Situ Statistical Analysis.

Energy Technology Data Exchange (ETDEWEB)

Pebay, Philippe Pierre [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Bennett, Janine Camille [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Kolla, Hemanth [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Borghesi, Giulio [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

2017-05-01

This report is a sequel to [PB16], in which we provided a first progress report on research and development towards a scalable, asynchronous many-task, in situ statistical analysis engine using the Legion runtime system. This earlier work included a prototype implementation of a proposed solution, using a proxy mini-application as a surrogate for a full-scale scientific simulation code. The first scalability studies were conducted with the above on modestly-sized experimental clusters. In contrast, in the current work we have integrated our in situ analysis engines with a full-size scientific application (S3D, using the Legion-SPMD model), and have conducted nu- merical tests on the largest computational platform currently available for DOE science ap- plications. We also provide details regarding the design and development of a light-weight asynchronous collectives library. We describe how this library is utilized within our SPMD- Legion S3D workflow, and compare the data aggregation technique deployed herein to the approach taken within our previous work.

Scalable Stream Processing with Quality of Service for Smart City Crowdsensing Applications

Directory of Open Access Journals (Sweden)

Paolo Bellavista

2013-12-01

Full Text Available Crowdsensing is emerging as a powerful paradigm capable of leveraging the collective, though imprecise, monitoring capabilities of common people carrying smartphones or other personal devices, which can effectively become real-time mobile sensors, collecting information about the physical places they live in. This unprecedented amount of information, considered collectively, offers new valuable opportunities to understand more thoroughly the environment in which we live and, more importantly, gives the chance to use this deeper knowledge to act and improve, in a virtuous loop, the environment itself. However, managing this process is a hard technical challenge, spanning several socio-technical issues: here, we focus on the related quality, reliability, and scalability trade-offs by proposing an architecture for crowdsensing platforms that dynamically self-configure and self-adapt depending on application-specific quality requirements. In the context of this general architecture, the paper will specifically focus on the Quasit distributed stream processing middleware, and show how Quasit can be used to process and analyze crowdsensing-generated data flows with differentiated quality requirements in a highly scalable and reliable way.

Volumetric Medical Image Coding: An Object-based, Lossy-to-lossless and Fully Scalable Approach

Science.gov (United States)

Danyali, Habibiollah; Mertins, Alfred

2011-01-01

In this article, an object-based, highly scalable, lossy-to-lossless 3D wavelet coding approach for volumetric medical image data (e.g., magnetic resonance (MR) and computed tomography (CT)) is proposed. The new method, called 3DOBHS-SPIHT, is based on the well-known set partitioning in the hierarchical trees (SPIHT) algorithm and supports both quality and resolution scalability. The 3D input data is grouped into groups of slices (GOS) and each GOS is encoded and decoded as a separate unit. The symmetric tree definition of the original 3DSPIHT is improved by introducing a new asymmetric tree structure. While preserving the compression efficiency, the new tree structure allows for a small size of each GOS, which not only reduces memory consumption during the encoding and decoding processes, but also facilitates more efficient random access to certain segments of slices. To achieve more compression efficiency, the algorithm only encodes the main object of interest in each 3D data set, which can have any arbitrary shape, and ignores the unnecessary background. The experimental results on some MR data sets show the good performance of the 3DOBHS-SPIHT algorithm for multi-resolution lossy-to-lossless coding. The compression efficiency, full scalability, and object-based features of the proposed approach, beside its lossy-to-lossless coding support, make it a very attractive candidate for volumetric medical image information archiving and transmission applications. PMID:22606653

Analysis of scalability of high-performance 3D image processing platform for virtual colonoscopy.

Science.gov (United States)

Yoshida, Hiroyuki; Wu, Yin; Cai, Wenli

2014-03-19

One of the key challenges in three-dimensional (3D) medical imaging is to enable the fast turn-around time, which is often required for interactive or real-time response. This inevitably requires not only high computational power but also high memory bandwidth due to the massive amount of data that need to be processed. For this purpose, we previously developed a software platform for high-performance 3D medical image processing, called HPC 3D-MIP platform, which employs increasingly available and affordable commodity computing systems such as the multicore, cluster, and cloud computing systems. To achieve scalable high-performance computing, the platform employed size-adaptive, distributable block volumes as a core data structure for efficient parallelization of a wide range of 3D-MIP algorithms, supported task scheduling for efficient load distribution and balancing, and consisted of a layered parallel software libraries that allow image processing applications to share the common functionalities. We evaluated the performance of the HPC 3D-MIP platform by applying it to computationally intensive processes in virtual colonoscopy. Experimental results showed a 12-fold performance improvement on a workstation with 12-core CPUs over the original sequential implementation of the processes, indicating the efficiency of the platform. Analysis of performance scalability based on the Amdahl's law for symmetric multicore chips showed the potential of a high performance scalability of the HPC 3D-MIP platform when a larger number of cores is available.

Hydra: a scalable proteomic search engine which utilizes the Hadoop distributed computing framework.

Science.gov (United States)

Lewis, Steven; Csordas, Attila; Killcoyne, Sarah; Hermjakob, Henning; Hoopmann, Michael R; Moritz, Robert L; Deutsch, Eric W; Boyle, John

2012-12-05

For shotgun mass spectrometry based proteomics the most computationally expensive step is in matching the spectra against an increasingly large database of sequences and their post-translational modifications with known masses. Each mass spectrometer can generate data at an astonishingly high rate, and the scope of what is searched for is continually increasing. Therefore solutions for improving our ability to perform these searches are needed. We present a sequence database search engine that is specifically designed to run efficiently on the Hadoop MapReduce distributed computing framework. The search engine implements the K-score algorithm, generating comparable output for the same input files as the original implementation. The scalability of the system is shown, and the architecture required for the development of such distributed processing is discussed. The software is scalable in its ability to handle a large peptide database, numerous modifications and large numbers of spectra. Performance scales with the number of processors in the cluster, allowing throughput to expand with the available resources.

PanDA Beyond ATLAS : A Scalable Workload Management System For Data Intensive Science

CERN Document Server

Borodin, M; The ATLAS collaboration; Jha, S; Golubkov, D; Klimentov, A; Maeno, T; Nilsson, P; Oleynik, D; Panitkin, S; Petrosyan, A; Schovancova, J; Vaniachine, A; Wenaus, T

2014-01-01

The LHC experiments are today at the leading edge of large scale distributed data-intensive computational science. The LHC's ATLAS experiment processes data volumes which are particularly extreme, over 140 PB to date, distributed worldwide at over of 120 sites. An important element in the success of the exciting physics results from ATLAS is the highly scalable integrated workflow and dataflow management afforded by the PanDA workload management system, used for all the distributed computing needs of the experiment. The PanDA design is not experiment specific and PanDA is now being extended to support other data intensive scientific applications. PanDA was cited as an example of "a high performance, fault tolerant software for fast, scalable access to data repositories of many kinds" during the "Big Data Research and Development Initiative" announcement, a 200 million USD U.S. government investment in tools to handle huge volumes of digital data needed to spur science and engineering discoveries. In this talk...

Scalable real space pseudopotential density functional codes for materials in the exascale regime

Science.gov (United States)

Lena, Charles; Chelikowsky, James; Schofield, Grady; Biller, Ariel; Kronik, Leeor; Saad, Yousef; Deslippe, Jack

Real-space pseudopotential density functional theory has proven to be an efficient method for computing the properties of matter in many different states and geometries, including liquids, wires, slabs, and clusters with and without spin polarization. Fully self-consistent solutions using this approach have been routinely obtained for systems with thousands of atoms. Yet, there are many systems of notable larger sizes where quantum mechanical accuracy is desired, but scalability proves to be a hindrance. Such systems include large biological molecules, complex nanostructures, or mismatched interfaces. We will present an overview of our new massively parallel algorithms, which offer improved scalability in preparation for exascale supercomputing. We will illustrate these algorithms by considering the electronic structure of a Si nanocrystal exceeding 104 atoms. Support provided by the SciDAC program, Department of Energy, Office of Science, Advanced Scientific Computing Research and Basic Energy Sciences. Grant Numbers DE-SC0008877 (Austin) and DE-FG02-12ER4 (Berkeley).

A Scalable and Modular Dome Illumination System for Scientific Microphotography on a Budget.

Directory of Open Access Journals (Sweden)

Ricardo Kawada

Full Text Available A scalable and modular LED illumination dome for microscopic scientific photography is described and illustrated, and methods for constructing such a dome are detailed. Dome illumination for insect specimens has become standard practice across the field of insect systematics, but many dome designs remain expensive and inflexible with respect to new LED technology. Further, a one-size-fits-all dome cannot accommodate the large breadth of insect size encountered in nature, forcing the photographer to adapt, in some cases, to a less than ideal dome design. The dome described here is scalable, as it is based on a isodecahedron, and the template for the dome is available as a downloaded file from the internet that can be printed on any printer, on the photographer's choice of media. As a result, a photographer can afford, using this design, to produce a series of domes of various sizes and materials, and LED ring lights of various sizes and color temperatures, depending on the need.

The TOTEM DAQ based on the Scalable Readout System (SRS)

Science.gov (United States)

Quinto, Michele; Cafagna, Francesco S.; Fiergolski, Adrian; Radicioni, Emilio

2018-02-01

The TOTEM (TOTal cross section, Elastic scattering and diffraction dissociation Measurement at the LHC) experiment at LHC, has been designed to measure the total proton-proton cross-section and study the elastic and diffractive scattering at the LHC energies. In order to cope with the increased machine luminosity and the higher statistic required by the extension of the TOTEM physics program, approved for the LHC's Run Two phase, the previous VME based data acquisition system has been replaced with a new one based on the Scalable Readout System. The system features an aggregated data throughput of 2GB / s towards the online storage system. This makes it possible to sustain a maximum trigger rate of ˜ 24kHz, to be compared with the 1KHz rate of the previous system. The trigger rate is further improved by implementing zero-suppression and second-level hardware algorithms in the Scalable Readout System. The new system fulfils the requirements for an increased efficiency, providing higher bandwidth, and increasing the purity of the data recorded. Moreover full compatibility has been guaranteed with the legacy front-end hardware, as well as with the DAQ interface of the CMS experiment and with the LHC's Timing, Trigger and Control distribution system. In this contribution we describe in detail the architecture of full system and its performance measured during the commissioning phase at the LHC Interaction Point.

Improving diabetes medication adherence: successful, scalable interventions

Directory of Open Access Journals (Sweden)

Zullig LL

2015-01-01

Full Text Available Leah L Zullig,1,2 Walid F Gellad,3,4 Jivan Moaddeb,2,5 Matthew J Crowley,1,2 William Shrank,6 Bradi B Granger,7 Christopher B Granger,8 Troy Trygstad,9 Larry Z Liu,10 Hayden B Bosworth1,2,7,11 1Center for Health Services Research in Primary Care, Durham Veterans Affairs Medical Center, Durham, NC, USA; 2Department of Medicine, Duke University, Durham, NC, USA; 3Center for Health Equity Research and Promotion, Pittsburgh Veterans Affairs Medical Center, Pittsburgh, PA, USA; 4Division of General Internal Medicine, University of Pittsburgh, Pittsburgh, PA, USA; 5Institute for Genome Sciences and Policy, Duke University, Durham, NC, USA; 6CVS Caremark Corporation; 7School of Nursing, Duke University, Durham, NC, USA; 8Department of Medicine, Division of Cardiology, Duke University School of Medicine, Durham, NC, USA; 9North Carolina Community Care Networks, Raleigh, NC, USA; 10Pfizer, Inc., and Weill Medical College of Cornell University, New York, NY, USA; 11Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA Abstract: Effective medications are a cornerstone of prevention and disease treatment, yet only about half of patients take their medications as prescribed, resulting in a common and costly public health challenge for the US healthcare system. Since poor medication adherence is a complex problem with many contributing causes, there is no one universal solution. This paper describes interventions that were not only effective in improving medication adherence among patients with diabetes, but were also potentially scalable (ie, easy to implement to a large population. We identify key characteristics that make these interventions effective and scalable. This information is intended to inform healthcare systems seeking proven, low resource, cost-effective solutions to improve medication adherence. Keywords: medication adherence, diabetes mellitus, chronic disease, dissemination research

Toward optimized light utilization in nanowire arrays using scalable nanosphere lithography and selected area growth.

Science.gov (United States)

Madaria, Anuj R; Yao, Maoqing; Chi, Chunyung; Huang, Ningfeng; Lin, Chenxi; Li, Ruijuan; Povinelli, Michelle L; Dapkus, P Daniel; Zhou, Chongwu

2012-06-13

Vertically aligned, catalyst-free semiconducting nanowires hold great potential for photovoltaic applications, in which achieving scalable synthesis and optimized optical absorption simultaneously is critical. Here, we report combining nanosphere lithography (NSL) and selected area metal-organic chemical vapor deposition (SA-MOCVD) for the first time for scalable synthesis of vertically aligned gallium arsenide nanowire arrays, and surprisingly, we show that such nanowire arrays with patterning defects due to NSL can be as good as highly ordered nanowire arrays in terms of optical absorption and reflection. Wafer-scale patterning for nanowire synthesis was done using a polystyrene nanosphere template as a mask. Nanowires grown from substrates patterned by NSL show similar structural features to those patterned using electron beam lithography (EBL). Reflection of photons from the NSL-patterned nanowire array was used as a measure of the effect of defects present in the structure. Experimentally, we show that GaAs nanowires as short as 130 nm show reflection of <10% over the visible range of the solar spectrum. Our results indicate that a highly ordered nanowire structure is not necessary: despite the "defects" present in NSL-patterned nanowire arrays, their optical performance is similar to "defect-free" structures patterned by more costly, time-consuming EBL methods. Our scalable approach for synthesis of vertical semiconducting nanowires can have application in high-throughput and low-cost optoelectronic devices, including solar cells.

NASA and the National Climate Assessment: Promoting awareness of NASA Earth science

Science.gov (United States)

Leidner, A. K.

2014-12-01

NASA Earth science observations, models, analyses, and applications made significant contributions to numerous aspects of the Third National Climate Assessment (NCA) report and are contributing to sustained climate assessment activities. The agency's goal in participating in the NCA was to ensure that NASA scientific resources were made available to understand the current state of climate change science and climate change impacts. By working with federal agency partners and stakeholder communities to develop and write the report, the agency was able to raise awareness of NASA climate science with audiences beyond the traditional NASA community. To support assessment activities within the NASA community, the agency sponsored two competitive programs that not only funded research and tools for current and future assessments, but also increased capacity within our community to conduct assessment-relevant science and to participate in writing assessments. Such activities fostered the ability of graduate students, post-docs, and senior researchers to learn about the science needs of climate assessors and end-users, which can guide future research activities. NASA also contributed to developing the Global Change Information System, which deploys information from the NCA to scientists, decision makers, and the public, and thus contributes to climate literacy. Finally, NASA satellite imagery and animations used in the Third NCA helped the pubic and decision makers visualize climate changes and were frequently used in social media to communicate report key findings. These resources are also key for developing educational materials that help teachers and students explore regional climate change impacts and opportunities for responses.

Experimental demonstration of an improved EPON architecture using OFDMA for bandwidth scalable LAN emulation

DEFF Research Database (Denmark)

Deng, Lei; Zhao, Ying; Yu, Xianbin

2011-01-01

We propose and demonstrate an improved Ethernet passive optical network (EPON) architecture supporting bandwidth-scalable physical layer local area network (LAN) emulation. Due to the use of orthogonal frequency division multiple access (OFDMA) technology for the LAN traffic transmission, there i...

Update on NASA Microelectronics Activities

Science.gov (United States)

Label, Kenneth A.; Sampson, Michael J.; Casey, Megan; Lauenstein, Jean-Marie

2017-01-01

Mission Statement: The NASA Electronic Parts and Packaging (NEPP) Program provides NASA's leadership for developing and maintaining guidance for the screening, qualification, test. and usage of EEE parts by NASA as well as in collaboration with other government Agencies and industry. NASA Space Technology Mission Directorate (STMD) "STMD rapidly develops, demonstrates, and infuses revolutionary, high-payoff technologies through transparent, collaborative partnerships, expanding the boundaries of the aerospace enterprise." Mission Statement: The Space Environments Testing Management Office (SETMO) will identify, prioritize, and manage a select suite of Agency key capabilities/assets that are deemed to be essential to the future needs of NASA or the nation, including some capabilities that lack an adequate business base over the budget horizon. NESC mission is to perform value-added independent testing, analysis, and assessments of NASA's high-risk projects to ensure safety and mission success. NASA Space Environments and Avionics Fellows as well as Radiation and EEE Parts Community of Practice (CoP) leads.

Coalescent: an open-source and scalable framework for exact calculations in coalescent theory

Science.gov (United States)

2012-01-01

Background Currently, there is no open-source, cross-platform and scalable framework for coalescent analysis in population genetics. There is no scalable GUI based user application either. Such a framework and application would not only drive the creation of more complex and realistic models but also make them truly accessible. Results As a first attempt, we built a framework and user application for the domain of exact calculations in coalescent analysis. The framework provides an API with the concepts of model, data, statistic, phylogeny, gene tree and recursion. Infinite-alleles and infinite-sites models are considered. It defines pluggable computations such as counting and listing all the ancestral configurations and genealogies and computing the exact probability of data. It can visualize a gene tree, trace and visualize the internals of the recursion algorithm for further improvement and attach dynamically a number of output processors. The user application defines jobs in a plug-in like manner so that they can be activated, deactivated, installed or uninstalled on demand. Multiple jobs can be run and their inputs edited. Job inputs are persisted across restarts and running jobs can be cancelled where applicable. Conclusions Coalescent theory plays an increasingly important role in analysing molecular population genetic data. Models involved are mathematically difficult and computationally challenging. An open-source, scalable framework that lets users immediately take advantage of the progress made by others will enable exploration of yet more difficult and realistic models. As models become more complex and mathematically less tractable, the need for an integrated computational approach is obvious. Object oriented designs, though has upfront costs, are practical now and can provide such an integrated approach. PMID:23033878

Coalescent: an open-source and scalable framework for exact calculations in coalescent theory

Directory of Open Access Journals (Sweden)

Tewari Susanta

2012-10-01

Full Text Available Abstract Background Currently, there is no open-source, cross-platform and scalable framework for coalescent analysis in population genetics. There is no scalable GUI based user application either. Such a framework and application would not only drive the creation of more complex and realistic models but also make them truly accessible. Results As a first attempt, we built a framework and user application for the domain of exact calculations in coalescent analysis. The framework provides an API with the concepts of model, data, statistic, phylogeny, gene tree and recursion. Infinite-alleles and infinite-sites models are considered. It defines pluggable computations such as counting and listing all the ancestral configurations and genealogies and computing the exact probability of data. It can visualize a gene tree, trace and visualize the internals of the recursion algorithm for further improvement and attach dynamically a number of output processors. The user application defines jobs in a plug-in like manner so that they can be activated, deactivated, installed or uninstalled on demand. Multiple jobs can be run and their inputs edited. Job inputs are persisted across restarts and running jobs can be cancelled where applicable. Conclusions Coalescent theory plays an increasingly important role in analysing molecular population genetic data. Models involved are mathematically difficult and computationally challenging. An open-source, scalable framework that lets users immediately take advantage of the progress made by others will enable exploration of yet more difficult and realistic models. As models become more complex and mathematically less tractable, the need for an integrated computational approach is obvious. Object oriented designs, though has upfront costs, are practical now and can provide such an integrated approach.

Highly Scalable Asynchronous Computing Method for Partial Differential Equations: A Path Towards Exascale

Science.gov (United States)

Konduri, Aditya

Many natural and engineering systems are governed by nonlinear partial differential equations (PDEs) which result in a multiscale phenomena, e.g. turbulent flows. Numerical simulations of these problems are computationally very expensive and demand for extreme levels of parallelism. At realistic conditions, simulations are being carried out on massively parallel computers with hundreds of thousands of processing elements (PEs). It has been observed that communication between PEs as well as their synchronization at these extreme scales take up a significant portion of the total simulation time and result in poor scalability of codes. This issue is likely to pose a bottleneck in scalability of codes on future Exascale systems. In this work, we propose an asynchronous computing algorithm based on widely used finite difference methods to solve PDEs in which synchronization between PEs due to communication is relaxed at a mathematical level. We show that while stability is conserved when schemes are used asynchronously, accuracy is greatly degraded. Since message arrivals at PEs are random processes, so is the behavior of the error. We propose a new statistical framework in which we show that average errors drop always to first-order regardless of the original scheme. We propose new asynchrony-tolerant schemes that maintain accuracy when synchronization is relaxed. The quality of the solution is shown to depend, not only on the physical phenomena and numerical schemes, but also on the characteristics of the computing machine. A novel algorithm using remote memory access communications has been developed to demonstrate excellent scalability of the method for large-scale computing. Finally, we present a path to extend this method in solving complex multi-scale problems on Exascale machines.

Scalable group level probabilistic sparse factor analysis

DEFF Research Database (Denmark)

Hinrich, Jesper Løve; Nielsen, Søren Føns Vind; Riis, Nicolai Andre Brogaard

2017-01-01

Many data-driven approaches exist to extract neural representations of functional magnetic resonance imaging (fMRI) data, but most of them lack a proper probabilistic formulation. We propose a scalable group level probabilistic sparse factor analysis (psFA) allowing spatially sparse maps, component...... pruning using automatic relevance determination (ARD) and subject specific heteroscedastic spatial noise modeling. For task-based and resting state fMRI, we show that the sparsity constraint gives rise to components similar to those obtained by group independent component analysis. The noise modeling...... shows that noise is reduced in areas typically associated with activation by the experimental design. The psFA model identifies sparse components and the probabilistic setting provides a natural way to handle parameter uncertainties. The variational Bayesian framework easily extends to more complex...

Building a scalable event-level metadata service for ATLAS

International Nuclear Information System (INIS)

Cranshaw, J; Malon, D; Goosens, L; Viegas, F T A; McGlone, H

2008-01-01

The ATLAS TAG Database is a multi-terabyte event-level metadata selection system, intended to allow discovery, selection of and navigation to events of interest to an analysis. The TAG Database encompasses file- and relational-database-resident event-level metadata, distributed across all ATLAS Tiers. An oracle hosted global TAG relational database, containing all ATLAS events, implemented in Oracle, will exist at Tier O. Implementing a system that is both performant and manageable at this scale is a challenge. A 1 TB relational TAG Database has been deployed at Tier 0 using simulated tag data. The database contains one billion events, each described by two hundred event metadata attributes, and is currently undergoing extensive testing in terms of queries, population and manageability. These 1 TB tests aim to demonstrate and optimise the performance and scalability of an Oracle TAG Database on a global scale. Partitioning and indexing strategies are crucial to well-performing queries and manageability of the database and have implications for database population and distribution, so these are investigated. Physics query patterns are anticipated, but a crucial feature of the system must be to support a broad range of queries across all attributes. Concurrently, event tags from ATLAS Computing System Commissioning distributed simulations are accumulated in an Oracle-hosted database at CERN, providing an event-level selection service valuable for user experience and gathering information about physics query patterns. In this paper we describe the status of the Global TAG relational database scalability work and highlight areas of future direction

Joint-layer encoder optimization for HEVC scalable extensions

Science.gov (United States)

Tsai, Chia-Ming; He, Yuwen; Dong, Jie; Ye, Yan; Xiu, Xiaoyu; He, Yong

2014-09-01

Scalable video coding provides an efficient solution to support video playback on heterogeneous devices with various channel conditions in heterogeneous networks. SHVC is the latest scalable video coding standard based on the HEVC standard. To improve enhancement layer coding efficiency, inter-layer prediction including texture and motion information generated from the base layer is used for enhancement layer coding. However, the overall performance of the SHVC reference encoder is not fully optimized because rate-distortion optimization (RDO) processes in the base and enhancement layers are independently considered. It is difficult to directly extend the existing joint-layer optimization methods to SHVC due to the complicated coding tree block splitting decisions and in-loop filtering process (e.g., deblocking and sample adaptive offset (SAO) filtering) in HEVC. To solve those problems, a joint-layer optimization method is proposed by adjusting the quantization parameter (QP) to optimally allocate the bit resource between layers. Furthermore, to make more proper resource allocation, the proposed method also considers the viewing probability of base and enhancement layers according to packet loss rate. Based on the viewing probability, a novel joint-layer RD cost function is proposed for joint-layer RDO encoding. The QP values of those coding tree units (CTUs) belonging to lower layers referenced by higher layers are decreased accordingly, and the QP values of those remaining CTUs are increased to keep total bits unchanged. Finally the QP values with minimal joint-layer RD cost are selected to match the viewing probability. The proposed method was applied to the third temporal level (TL-3) pictures in the Random Access configuration. Simulation results demonstrate that the proposed joint-layer optimization method can improve coding performance by 1.3% for these TL-3 pictures compared to the SHVC reference encoder without joint-layer optimization.

Scalable on-chip quantum state tomography

Science.gov (United States)

Titchener, James G.; Gräfe, Markus; Heilmann, René; Solntsev, Alexander S.; Szameit, Alexander; Sukhorukov, Andrey A.

2018-03-01

Quantum information systems are on a path to vastly exceed the complexity of any classical device. The number of entangled qubits in quantum devices is rapidly increasing, and the information required to fully describe these systems scales exponentially with qubit number. This scaling is the key benefit of quantum systems, however it also presents a severe challenge. To characterize such systems typically requires an exponentially long sequence of different measurements, becoming highly resource demanding for large numbers of qubits. Here we propose and demonstrate a novel and scalable method for characterizing quantum systems based on expanding a multi-photon state to larger dimensionality. We establish that the complexity of this new measurement technique only scales linearly with the number of qubits, while providing a tomographically complete set of data without a need for reconfigurability. We experimentally demonstrate an integrated photonic chip capable of measuring two- and three-photon quantum states with statistical reconstruction fidelity of 99.71%.

Scalable Faceted Ranking in Tagging Systems

Science.gov (United States)

Orlicki, José I.; Alvarez-Hamelin, J. Ignacio; Fierens, Pablo I.

Nowadays, web collaborative tagging systems which allow users to upload, comment on and recommend contents, are growing. Such systems can be represented as graphs where nodes correspond to users and tagged-links to recommendations. In this paper we analyze the problem of computing a ranking of users with respect to a facet described as a set of tags. A straightforward solution is to compute a PageRank-like algorithm on a facet-related graph, but it is not feasible for online computation. We propose an alternative: (i) a ranking for each tag is computed offline on the basis of tag-related subgraphs; (ii) a faceted order is generated online by merging rankings corresponding to all the tags in the facet. Based on the graph analysis of YouTube and Flickr, we show that step (i) is scalable. We also present efficient algorithms for step (ii), which are evaluated by comparing their results with two gold standards.

Novel flat datacenter network architecture based on scalable and flow-controlled optical switch system

NARCIS (Netherlands)

Miao, W.; Luo, J.; Di Lucente, S.; Dorren, H.J.S.; Calabretta, N.

2013-01-01

We propose and demonstrate an optical flat datacenter network based on scalable optical switch system with optical flow control. 4×4 dynamic switch operation at 40 Gb/s reported 300ns minimum end-to-end latency (including 25m transmission link) and

Scalable web services for the PSIPRED Protein Analysis Workbench.

Science.gov (United States)

Buchan, Daniel W A; Minneci, Federico; Nugent, Tim C O; Bryson, Kevin; Jones, David T

2013-07-01

Here, we present the new UCL Bioinformatics Group's PSIPRED Protein Analysis Workbench. The Workbench unites all of our previously available analysis methods into a single web-based framework. The new web portal provides a greatly streamlined user interface with a number of new features to allow users to better explore their results. We offer a number of additional services to enable computationally scalable execution of our prediction methods; these include SOAP and XML-RPC web server access and new HADOOP packages. All software and services are available via the UCL Bioinformatics Group website at http://bioinf.cs.ucl.ac.uk/.

Scalable creation of gold nanostructures on high performance engineering polymeric substrate

Science.gov (United States)

Jia, Kun; Wang, Pan; Wei, Shiliang; Huang, Yumin; Liu, Xiaobo

2017-12-01

The article reveals a facile protocol for scalable production of gold nanostructures on a high performance engineering thermoplastic substrate made of polyarylene ether nitrile (PEN) for the first time. Firstly, gold thin films with different thicknesses of 2 nm, 4 nm and 6 nm were evaporated on a spin-coated PEN substrate on glass slide in vacuum. Next, the as-evaporated samples were thermally annealed around the glass transition temperature of the PEN substrate, on which gold nanostructures with island-like morphology were created. Moreover, it was found that the initial gold evaporation thickness and annealing atmosphere played an important role in determining the morphology and plasmonic properties of the formulated Au NPs. Interestingly, we discovered that isotropic Au NPs can be easily fabricated on the freestanding PEN substrate, which was fabricated by a cost-effective polymer solution casting method. More specifically, monodispersed Au nanospheres with an average size of ∼60 nm were obtained after annealing a 4 nm gold film covered PEN casting substrate at 220 °C for 2 h in oxygen. Therefore, the scalable production of Au NPs with controlled morphology on PEN substrate would open the way for development of robust flexible nanosensors and optical devices using high performance engineering polyarylene ethers.

Optimal erasure protection for scalably compressed video streams with limited retransmission.

Science.gov (United States)

Taubman, David; Thie, Johnson

2005-08-01

This paper shows how the priority encoding transmission (PET) framework may be leveraged to exploit both unequal error protection and limited retransmission for RD-optimized delivery of streaming media. Previous work on scalable media protection with PET has largely ignored the possibility of retransmission. Conversely, the PET framework has not been harnessed by the substantial body of previous work on RD optimized hybrid forward error correction/automatic repeat request schemes. We limit our attention to sources which can be modeled as independently compressed frames (e.g., video frames), where each element in the scalable representation of each frame can be transmitted in one or both of two transmission slots. An optimization algorithm determines the level of protection which should be assigned to each element in each slot, subject to transmission bandwidth constraints. To balance the protection assigned to elements which are being transmitted for the first time with those which are being retransmitted, the proposed algorithm formulates a collection of hypotheses concerning its own behavior in future transmission slots. We show how the PET framework allows for a decoupled optimization algorithm with only modest complexity. Experimental results obtained with Motion JPEG2000 compressed video demonstrate that substantial performance benefits can be obtained using the proposed framework.

Scalable multi-grid preconditioning techniques for the even-parity S_N solver in UNIC

International Nuclear Information System (INIS)

Mahadevan, Vijay S.; Smith, Michael A.

2011-01-01

The Even-parity neutron transport equation with FE-S_N discretization is solved traditionally using SOR preconditioned CG method at the lowest level of iterations in order to compute the criticality in reactor analysis problems. The use of high order isoparametric finite elements prohibits the formation of the discrete operator explicitly due to memory constraints in peta scale architectures. Hence, a h-p multi-grid preconditioner based on linear tessellation of the higher order mesh is introduced here for the space-angle system and compared against SOR and Algebraic MG black-box solvers. The performance and scalability of the multi-grid scheme was determined for two test problems and found to be competitive in terms of both computational time and memory requirements. The implementation of this preconditioner in an even-parity solver like UNIC from ANL can further enable high fidelity calculations in a scalable manner on peta flop machines. (author)

A Secure and Stable Multicast Overlay Network with Load Balancing for Scalable IPTV Services

Directory of Open Access Journals (Sweden)

Tsao-Ta Wei

2012-01-01

Full Text Available The emerging multimedia Internet application IPTV over P2P network preserves significant advantages in scalability. IPTV media content delivered in P2P networks over public Internet still preserves the issues of privacy and intellectual property rights. In this paper, we use SIP protocol to construct a secure application-layer multicast overlay network for IPTV, called SIPTVMON. SIPTVMON can secure all the IPTV media delivery paths against eavesdroppers via elliptic-curve Diffie-Hellman (ECDH key exchange on SIP signaling and AES encryption. Its load-balancing overlay tree is also optimized from peer heterogeneity and churn of peer joining and leaving to minimize both service degradation and latency. The performance results from large-scale simulations and experiments on different optimization criteria demonstrate SIPTVMON's cost effectiveness in quality of privacy protection, stability from user churn, and good perceptual quality of objective PSNR values for scalable IPTV services over Internet.

Ultra-Scalable Algorithms for Large-Scale Uncertainty Quantification in Inverse Wave Propagation

Science.gov (United States)

2016-03-04

gradient), as well as linear systems with Hessian operators that arise in the trace estimation (along with incremental forward/adjoint wave equations ...with the Elemental library [54] to enable fast and scalable randomized linear algebra . We have also been working on domain decomposition...discontinuous Petrov Galerkin method, in Recent Developments in Discontinuous Galerkin Finite Element Methods for Partial Differential Equations : 2012

NASA Water Resources Program

Science.gov (United States)

Toll, David L.

2011-01-01

With increasing population pressure and water usage coupled with climate variability and change, water issues are being reported by numerous groups as the most critical environmental problems facing us in the 21st century. Competitive uses and the prevalence of river basins and aquifers that extend across boundaries engender political tensions between communities, stakeholders and countries. In addition to the numerous water availability issues, water quality related problems are seriously affecting human health and our environment. The potential crises and conflicts especially arise when water is competed among multiple uses. For example, urban areas, environmental and recreational uses, agriculture, and energy production compete for scarce resources, not only in the Western U.S. but throughout much of the U.S. and also in numerous parts of the world. Mitigating these conflicts and meeting water demands and needs requires using existing water resources more efficiently. The NASA Water Resources Program Element works to use NASA products and technology to address these critical water issues. The primary goal of the Water Resources is to facilitate application of NASA Earth science products as a routine use in integrated water resources management for the sustainable use of water. This also includes the extreme events of drought and floods and the adaptation to the impacts from climate change. NASA satellite and Earth system observations of water and related data provide a huge volume of valuable data in both near-real-time and extended back nearly 50 years about the Earth's land surface conditions such as precipitation, snow, soil moisture, water levels, land cover type, vegetation type, and health. NASA Water Resources Program works closely to use NASA and Earth science data with other U.S. government agencies, universities, and non-profit and private sector organizations both domestically and internationally. The NASA Water Resources Program organizes its

NASA Operational Environment Team (NOET): NASA's key to environmental technology

Science.gov (United States)

Cook, Beth

1993-01-01

NASA has stepped forward to face the environmental challenge to eliminate the use of Ozone-Layer Depleting Substances (OLDS) and to reduce our Hazardous Air Pollutants (HAP) by 50 percent in 1995. These requirements have been issued by the Clean Air Act, the Montreal Protocol, and various other legislative acts. A proactive group, the NASA Operational Environment Team or NOET, received its charter in April 1992 and was tasked with providing a network through which replacement activities and development experiences can be shared. This is a NASA-wide team which supports the research and development community by sharing information both in person and via a computerized network, assisting in specification and standard revisions, developing cleaner propulsion systems, and exploring environmentally-compliant alternatives to current processes.

Scalable fractionation of iron oxide nanoparticles using a CO2 gas-expanded liquid system

International Nuclear Information System (INIS)

Vengsarkar, Pranav S.; Xu, Rui; Roberts, Christopher B.

2015-01-01

Iron oxide nanoparticles exhibit highly size-dependent physicochemical properties that are important in applications such as catalysis and environmental remediation. In order for these size-dependent properties to be effectively harnessed for industrial applications scalable and cost-effective techniques for size-controlled synthesis or size separation must be developed. The synthesis of monodisperse iron oxide nanoparticles can be a prohibitively expensive process on a large scale. An alternative involves the use of inexpensive synthesis procedures followed by a size-selective processing technique. While there are many techniques available to fractionate nanoparticles, many of the techniques are unable to efficiently fractionate iron oxide nanoparticles in a scalable and inexpensive manner. A scalable apparatus capable of fractionating large quantities of iron oxide nanoparticles into distinct fractions of different sizes and size distributions has been developed. Polydisperse iron oxide nanoparticles (2–20 nm) coated with oleic acid used in this study were synthesized using a simple and inexpensive version of the popular coprecipitation technique. This apparatus uses hexane as a CO 2 gas-expanded liquid to controllably precipitate nanoparticles inside a 1L high-pressure reactor. This paper demonstrates the operation of this new apparatus and for the first time shows the successful fractionation results on a system of metal oxide nanoparticles, with initial nanoparticle concentrations in the gram-scale. The analysis of the obtained fractions was performed using transmission electron microscopy and dynamic light scattering. The use of this simple apparatus provides a pathway to separate large quantities of iron oxide nanoparticles based upon their size for use in various industrial applications.

A Scalable Version of the Navy Operational Global Atmospheric Prediction System Spectral Forecast Model

Directory of Open Access Journals (Sweden)

Thomas E. Rosmond

2000-01-01

Full Text Available The Navy Operational Global Atmospheric Prediction System (NOGAPS includes a state-of-the-art spectral forecast model similar to models run at several major operational numerical weather prediction (NWP centers around the world. The model, developed by the Naval Research Laboratory (NRL in Monterey, California, has run operational at the Fleet Numerical Meteorological and Oceanographic Center (FNMOC since 1982, and most recently is being run on a Cray C90 in a multi-tasked configuration. Typically the multi-tasked code runs on 10 to 15 processors with overall parallel efficiency of about 90%. resolution is T159L30, but other operational and research applications run at significantly lower resolutions. A scalable NOGAPS forecast model has been developed by NRL in anticipation of a FNMOC C90 replacement in about 2001, as well as for current NOGAPS research requirements to run on DOD High-Performance Computing (HPC scalable systems. The model is designed to run with message passing (MPI. Model design criteria include bit reproducibility for different processor numbers and reasonably efficient performance on fully shared memory, distributed memory, and distributed shared memory systems for a wide range of model resolutions. Results for a wide range of processor numbers, model resolutions, and different vendor architectures are presented. Single node performance has been disappointing on RISC based systems, at least compared to vector processor performance. This is a common complaint, and will require careful re-examination of traditional numerical weather prediction (NWP model software design and data organization to fully exploit future scalable architectures.

Fast and scalable inequality joins

KAUST Repository

Khayyat, Zuhair

2016-09-07

Inequality joins, which is to join relations with inequality conditions, are used in various applications. Optimizing joins has been the subject of intensive research ranging from efficient join algorithms such as sort-merge join, to the use of efficient indices such as (Formula presented.)-tree, (Formula presented.)-tree and Bitmap. However, inequality joins have received little attention and queries containing such joins are notably very slow. In this paper, we introduce fast inequality join algorithms based on sorted arrays and space-efficient bit-arrays. We further introduce a simple method to estimate the selectivity of inequality joins which is then used to optimize multiple predicate queries and multi-way joins. Moreover, we study an incremental inequality join algorithm to handle scenarios where data keeps changing. We have implemented a centralized version of these algorithms on top of PostgreSQL, a distributed version on top of Spark SQL, and an existing data cleaning system, Nadeef. By comparing our algorithms against well-known optimization techniques for inequality joins, we show our solution is more scalable and several orders of magnitude faster. © 2016 Springer-Verlag Berlin Heidelberg

A Programmable, Scalable-Throughput Interleaver

Directory of Open Access Journals (Sweden)

E. J. C. Rijshouwer

2010-01-01

Full Text Available The interleaver stages of digital communication standards show a surprisingly large variation in throughput, state sizes, and permutation functions. Furthermore, data rates for 4G standards such as LTE-Advanced will exceed typical baseband clock frequencies of handheld devices. Multistream operation for Software Defined Radio and iterative decoding algorithms will call for ever higher interleave data rates. Our interleave machine is built around 8 single-port SRAM banks and can be programmed to generate up to 8 addresses every clock cycle. The scalable architecture combines SIMD and VLIW concepts with an efficient resolution of bank conflicts. A wide range of cellular, connectivity, and broadcast interleavers have been mapped on this machine, with throughputs up to more than 0.5 Gsymbol/second. Although it was designed for channel interleaving, the application domain of the interleaver extends also to Turbo interleaving. The presented configuration of the architecture is designed as a part of a programmable outer receiver on a prototype board. It offers (near universal programmability to enable the implementation of new interleavers. The interleaver measures 2.09 mm2 in 65 nm CMOS (including memories and proves functional on silicon.

A Programmable, Scalable-Throughput Interleaver

Directory of Open Access Journals (Sweden)

Rijshouwer EJC

2010-01-01

Full Text Available The interleaver stages of digital communication standards show a surprisingly large variation in throughput, state sizes, and permutation functions. Furthermore, data rates for 4G standards such as LTE-Advanced will exceed typical baseband clock frequencies of handheld devices. Multistream operation for Software Defined Radio and iterative decoding algorithms will call for ever higher interleave data rates. Our interleave machine is built around 8 single-port SRAM banks and can be programmed to generate up to 8 addresses every clock cycle. The scalable architecture combines SIMD and VLIW concepts with an efficient resolution of bank conflicts. A wide range of cellular, connectivity, and broadcast interleavers have been mapped on this machine, with throughputs up to more than 0.5 Gsymbol/second. Although it was designed for channel interleaving, the application domain of the interleaver extends also to Turbo interleaving. The presented configuration of the architecture is designed as a part of a programmable outer receiver on a prototype board. It offers (near universal programmability to enable the implementation of new interleavers. The interleaver measures 2.09 m in 65 nm CMOS (including memories and proves functional on silicon.

Scalable alcohol interventions - An online “Month off Booze” programme

Directory of Open Access Journals (Sweden)

Jussi Tolvi

2015-09-01

Club Soda has developed a scalable online intervention, supporting people who want to abstain from alcohol for a month, which will be piloted in October 2015. An evaluation of the programme is not possible at the time of writing this abstract, but will be completed in November 2015. Based on initial feedback and anecdotal evidence, however, the programme is expected to be a powerful tool helping people abstain for a set period of time, and in reducing their alcohol consumption after the programme as well.

Scalable Security and Accounting Services for Content-Based Publish/Subscribe Systems

OpenAIRE

Himanshu Khurana; Radostina K. Koleva

2006-01-01

Content-based publish/subscribe systems offer an interaction scheme that is appropriate for a variety of large-scale dynamic applications. However, widespread use of these systems is hindered by a lack of suitable security services. In this paper, we present scalable solutions for confidentiality, integrity, and authentication for these systems. We also provide verifiable usage-based accounting services, which are required for e-commerce and e-business applications that use publish/subscribe ...

75 FR 70951 - NASA Advisory Council; NASA Commercial Space Committee; Meeting

Science.gov (United States)

2010-11-19

.... ADDRESSES: NASA Headquarters, 300 E Street, SW., Glennan Conference Center Room 1Q39, Washington, DC 20546... identification such as a driver's license to enter the NASA Headquarters building (West Lobby--Visitor Control..., company affiliation (if applicable) to include address, telephone number, and their title, place of birth...

Temporal signal energy correction and low-complexity encoder feedback for lossy scalable video coding

NARCIS (Netherlands)

Loomans, M.J.H.; Koeleman, C.J.; With, de P.H.N.

2010-01-01

In this paper, we address two problems found in embedded implementations of Scalable Video Codecs (SVCs): the temporal signal energy distribution and frame-to-frame quality fluctuations. The unequal energy distribution between the low- and high-pass band with integer-based wavelets leads to

The writers guide to NASA. [NASA Centers and public affairs contacts

Science.gov (United States)

1978-01-01

NASA services of interest to writers and to the news media include personal interviews, daily audio reports of major missions, and projects via automated telephone, research assistance from historians or history monitors at technical libraries, the use of a collection of historical photographs, and the free loan of sound films of NASA research and development activities. The names and phones numbers are listed for public affairs contacts at Headquarters and at each of the major centers and their component installations. An overview of the six NASA program offices is included along with a vicinity map of each center and a description of their facilities and management responsibilities.

NASA Space Radiation Laboratory

Data.gov (United States)

Federal Laboratory Consortium — The NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory is a NASA funded facility, delivering heavy ion beams to a target area where scientists...

76 FR 64122 - NASA Advisory Committee; Renewal of NASA's International Space Station Advisory Committee Charter

Science.gov (United States)

2011-10-17

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice (11-095)] NASA Advisory Committee; Renewal of NASA's International Space Station Advisory Committee Charter AGENCY: National Aeronautics and Space Administration (NASA). ACTION: Notice of renewal and amendment of the Charter of the International...

Scalable Creation of Long-Lived Multipartite Entanglement

Science.gov (United States)

Kaufmann, H.; Ruster, T.; Schmiegelow, C. T.; Luda, M. A.; Kaushal, V.; Schulz, J.; von Lindenfels, D.; Schmidt-Kaler, F.; Poschinger, U. G.

2017-10-01

We demonstrate the deterministic generation of multipartite entanglement based on scalable methods. Four qubits are encoded in 40Ca+, stored in a microstructured segmented Paul trap. These qubits are sequentially entangled by laser-driven pairwise gate operations. Between these, the qubit register is dynamically reconfigured via ion shuttling operations, where ion crystals are separated and merged, and ions are moved in and out of a fixed laser interaction zone. A sequence consisting of three pairwise entangling gates yields a four-ion Greenberger-Horne-Zeilinger state |ψ ⟩=(1 /√{2 })(|0000 ⟩+|1111 ⟩) , and full quantum state tomography reveals a state fidelity of 94.4(3)%. We analyze the decoherence of this state and employ dynamic decoupling on the spatially distributed constituents to maintain 69(5)% coherence at a storage time of 1.1 sec.

NASA University Program Management Information System

Science.gov (United States)

2000-01-01

As basic policy, NASA believes that colleges and universities should be encouraged to participate in the nation's space and aeronautics program to the maximum extent practicable. Indeed, universities are considered as partners with government and industry in the nation's aerospace program. NASA:s objective is to have them bring their scientific, engineering, and social research competence to bear on aerospace problems and on the broader social, economic, and international implications of NASA's technical and scientific programs. It is expected that, in so doing, universities will strengthen both their research and their educational capabilities to contribute more effectively to the national well-being. NASA field codes and certain Headquarters program offices provide funds for those activities in universities which contribute to the mission needs of that particular NASA element. Although NASA has no predetermined amount of money to devote to university activities, the effort funded each year is substantial. This annual report is one means of documenting the NASA-university relationship, frequently denoted, collectively, as NASA's University Program. This report is consistent with agency accounting records, as the data is obtained from NASA:s Financial and Contractual Status (FACS) System, operated by the Financial Management Division and the Procurement Office. However, in accordance with interagency agreements, the orientation differs from that required for financial or procurement purposes. Any apparent discrepancies between this report and other NASA procurement or financial reports stem from the selection criteria for the data.* This report was prepared by the Education Division/FE, Office of Human Resources and Education, using a management information system which was modernized during FY 1993.

SciSpark: Highly Interactive and Scalable Model Evaluation and Climate Metrics for Scientific Data and Analysis

Data.gov (United States)

National Aeronautics and Space Administration — We will construct SciSpark, a scalable system for interactive model evaluation and for the rapid development of climate metrics and analyses. SciSpark directly...

Scalable Active Optical Access Network Using Variable High-Speed PLZT Optical Switch/Splitter

Science.gov (United States)

Ashizawa, Kunitaka; Sato, Takehiro; Tokuhashi, Kazumasa; Ishii, Daisuke; Okamoto, Satoru; Yamanaka, Naoaki; Oki, Eiji

This paper proposes a scalable active optical access network using high-speed Plumbum Lanthanum Zirconate Titanate (PLZT) optical switch/splitter. The Active Optical Network, called ActiON, using PLZT switching technology has been presented to increase the number of subscribers and the maximum transmission distance, compared to the Passive Optical Network (PON). ActiON supports the multicast slot allocation realized by running the PLZT switch elements in the splitter mode, which forces the switch to behave as an optical splitter. However, the previous ActiON creates a tradeoff between the network scalability and the power loss experienced by the optical signal to each user. It does not use the optical power efficiently because the optical power is simply divided into 0.5 to 0.5 without considering transmission distance from OLT to each ONU. The proposed network adopts PLZT switch elements in the variable splitter mode, which controls the split ratio of the optical power considering the transmission distance from OLT to each ONU, in addition to PLZT switch elements in existing two modes, the switching mode and the splitter mode. The proposed network introduces the flexible multicast slot allocation according to the transmission distance from OLT to each user and the number of required users using three modes, while keeping the advantages of ActiON, which are to support scalable and secure access services. Numerical results show that the proposed network dramatically reduces the required number of slots and supports high bandwidth efficiency services and extends the coverage of access network, compared to the previous ActiON, and the required computation time for selecting multicast users is less than 30msec, which is acceptable for on-demand broadcast services.

A scalable FPGA-based digitizing platform for radiation data acquisition

International Nuclear Information System (INIS)

Schiffer, Randolph T.; Flaska, Marek; Pozzi, Sara A.; Carney, Sean; Wentzloff, David D.

2011-01-01

Regulating the proliferation of nuclear materials has become an important issue in our society. In order to detect the radiation given off by nuclear materials, systems implementing detectors connected to data processing modules have been developed. We have implemented a scalable, portable detection platform with a data processing module about the size of an external DVD drive. The data processing component of our system utilizes real-time data handling and has the potential for growth and behavior modifications through custom FPGA code editing. The size of our system is dynamic, so additional input channels can be implemented if necessary. This paper presents a scalable, portable detection system capable of transmitting streaming data from its inputs to a PC or laptop. The system also performs tail/total integral pulse shape discrimination (PSD) in real time on the FPGA to filter the data and selectively transmit pulses to a PC. The data arrives at the inputs of the data capturing module, is processed in real time by the onboard FPGA and is then transferred to a PC or laptop via a PCIe cord in discrete packets. The maximum transfer rate from the FPGA to the PC is 2000 MB/s. The Detection for Nuclear Non-Proliferation Group at University of Michigan will use the detection platform to achieve pre-processing of radiation data in real time. Such pre-processing includes PSD, pulse height distributions and particle times of arrival.

NASA's Advanced Solar Sail Propulsion System for Low-Cost Deep Space Exploration and Science Missions that Use High Performance Rollable Composite Booms

Science.gov (United States)

Fernandez, Juan M.; Rose, Geoffrey K.; Younger, Casey J.; Dean, Gregory D.; Warren, Jerry E.; Stohlman, Olive R.; Wilkie, W. Keats

2017-01-01

Several low-cost solar sail technology demonstrator missions are under development in the United States. However, the mass saving derived benefits that composites can offer to such a mass critical spacecraft architecture have not been realized yet. This is due to the lack of suitable composite booms that can fit inside CubeSat platforms and ultimately be readily scalable to much larger sizes, where they can fully optimize their use. With this aim, a new effort focused at developing scalable rollable composite booms for solar sails and other deployable structures has begun. Seven meter booms used to deploy a 90 m2 class solar sail that can fit inside a 6U CubeSat have already been developed. The NASA road map to low-cost solar sail capability demonstration envisioned, consists of increasing the size of these composite booms to enable sailcrafts with a reflective area of up to 2000 m2 housed aboard small satellite platforms. This paper presents a solar sail system initially conceived to serve as a risk reduction alternative to Near Earth Asteroid (NEA) Scout's baseline design but that has recently been slightly redesigned and proposed for follow-on missions. The features of the booms and various deployment mechanisms for the booms and sail, as well as ground support equipment used during testing, are introduced. The results of structural analyses predict the performance of the system under microgravity conditions. Finally, the results of the functional and environmental testing campaign carried out are shown.

Scalability of Direct Solver for Non-stationary Cahn-Hilliard Simulations with Linearized time Integration Scheme

KAUST Repository

Woźniak, M.

2016-06-02

We study the features of a new mixed integration scheme dedicated to solving the non-stationary variational problems. The scheme is composed of the FEM approximation with respect to the space variable coupled with a 3-leveled time integration scheme with a linearized right-hand side operator. It was applied in solving the Cahn-Hilliard parabolic equation with a nonlinear, fourth-order elliptic part. The second order of the approximation along the time variable was proven. Moreover, the good scalability of the software based on this scheme was confirmed during simulations. We verify the proposed time integration scheme by monitoring the Ginzburg-Landau free energy. The numerical simulations are performed by using a parallel multi-frontal direct solver executed over STAMPEDE Linux cluster. Its scalability was compared to the results of the three direct solvers, including MUMPS, SuperLU and PaSTiX.

A Bit Stream Scalable Speech/Audio Coder Combining Enhanced Regular Pulse Excitation and Parametric Coding

Directory of Open Access Journals (Sweden)

Albertus C. den Brinker

2007-01-01

Full Text Available This paper introduces a new audio and speech broadband coding technique based on the combination of a pulse excitation coder and a standardized parametric coder, namely, MPEG-4 high-quality parametric coder. After presenting a series of enhancements to regular pulse excitation (RPE to make it suitable for the modeling of broadband signals, it is shown how pulse and parametric codings complement each other and how they can be merged to yield a layered bit stream scalable coder able to operate at different points in the quality bit rate plane. The performance of the proposed coder is evaluated in a listening test. The major result is that the extra functionality of the bit stream scalability does not come at the price of a reduced performance since the coder is competitive with standardized coders (MP3, AAC, SSC.

A Bit Stream Scalable Speech/Audio Coder Combining Enhanced Regular Pulse Excitation and Parametric Coding

Science.gov (United States)

Riera-Palou, Felip; den Brinker, Albertus C.

2007-12-01

This paper introduces a new audio and speech broadband coding technique based on the combination of a pulse excitation coder and a standardized parametric coder, namely, MPEG-4 high-quality parametric coder. After presenting a series of enhancements to regular pulse excitation (RPE) to make it suitable for the modeling of broadband signals, it is shown how pulse and parametric codings complement each other and how they can be merged to yield a layered bit stream scalable coder able to operate at different points in the quality bit rate plane. The performance of the proposed coder is evaluated in a listening test. The major result is that the extra functionality of the bit stream scalability does not come at the price of a reduced performance since the coder is competitive with standardized coders (MP3, AAC, SSC).

Proposed Use of the NASA Ames Nebula Cloud Computing Platform for Numerical Weather Prediction and the Distribution of High Resolution Satellite Imagery

Science.gov (United States)

Limaye, Ashutosh S.; Molthan, Andrew L.; Srikishen, Jayanthi

2010-01-01

The development of the Nebula Cloud Computing Platform at NASA Ames Research Center provides an open-source solution for the deployment of scalable computing and storage capabilities relevant to the execution of real-time weather forecasts and the distribution of high resolution satellite data to the operational weather community. Two projects at Marshall Space Flight Center may benefit from use of the Nebula system. The NASA Short-term Prediction Research and Transition (SPoRT) Center facilitates the use of unique NASA satellite data and research capabilities in the operational weather community by providing datasets relevant to numerical weather prediction, and satellite data sets useful in weather analysis. SERVIR provides satellite data products for decision support, emphasizing environmental threats such as wildfires, floods, landslides, and other hazards, with interests in numerical weather prediction in support of disaster response. The Weather Research and Forecast (WRF) model Environmental Modeling System (WRF-EMS) has been configured for Nebula cloud computing use via the creation of a disk image and deployment of repeated instances. Given the available infrastructure within Nebula and the "infrastructure as a service" concept, the system appears well-suited for the rapid deployment of additional forecast models over different domains, in response to real-time research applications or disaster response. Future investigations into Nebula capabilities will focus on the development of a web mapping server and load balancing configuration to support the distribution of high resolution satellite data sets to users within the National Weather Service and international partners of SERVIR.

The Open Connectome Project Data Cluster: Scalable Analysis and Vision for High-Throughput Neuroscience

Science.gov (United States)

Burns, Randal; Roncal, William Gray; Kleissas, Dean; Lillaney, Kunal; Manavalan, Priya; Perlman, Eric; Berger, Daniel R.; Bock, Davi D.; Chung, Kwanghun; Grosenick, Logan; Kasthuri, Narayanan; Weiler, Nicholas C.; Deisseroth, Karl; Kazhdan, Michael; Lichtman, Jeff; Reid, R. Clay; Smith, Stephen J.; Szalay, Alexander S.; Vogelstein, Joshua T.; Vogelstein, R. Jacob

2013-01-01

We describe a scalable database cluster for the spatial analysis and annotation of high-throughput brain imaging data, initially for 3-d electron microscopy image stacks, but for time-series and multi-channel data as well. The system was designed primarily for workloads that build connectomes— neural connectivity maps of the brain—using the parallel execution of computer vision algorithms on high-performance compute clusters. These services and open-science data sets are publicly available at openconnecto.me. The system design inherits much from NoSQL scale-out and data-intensive computing architectures. We distribute data to cluster nodes by partitioning a spatial index. We direct I/O to different systems—reads to parallel disk arrays and writes to solid-state storage—to avoid I/O interference and maximize throughput. All programming interfaces are RESTful Web services, which are simple and stateless, improving scalability and usability. We include a performance evaluation of the production system, highlighting the effec-tiveness of spatial data organization. PMID:24401992

The Open Connectome Project Data Cluster: Scalable Analysis and Vision for High-Throughput Neuroscience.

Science.gov (United States)

Burns, Randal; Roncal, William Gray; Kleissas, Dean; Lillaney, Kunal; Manavalan, Priya; Perlman, Eric; Berger, Daniel R; Bock, Davi D; Chung, Kwanghun; Grosenick, Logan; Kasthuri, Narayanan; Weiler, Nicholas C; Deisseroth, Karl; Kazhdan, Michael; Lichtman, Jeff; Reid, R Clay; Smith, Stephen J; Szalay, Alexander S; Vogelstein, Joshua T; Vogelstein, R Jacob

2013-01-01

We describe a scalable database cluster for the spatial analysis and annotation of high-throughput brain imaging data, initially for 3-d electron microscopy image stacks, but for time-series and multi-channel data as well. The system was designed primarily for workloads that build connectomes - neural connectivity maps of the brain-using the parallel execution of computer vision algorithms on high-performance compute clusters. These services and open-science data sets are publicly available at openconnecto.me. The system design inherits much from NoSQL scale-out and data-intensive computing architectures. We distribute data to cluster nodes by partitioning a spatial index. We direct I/O to different systems-reads to parallel disk arrays and writes to solid-state storage-to avoid I/O interference and maximize throughput. All programming interfaces are RESTful Web services, which are simple and stateless, improving scalability and usability. We include a performance evaluation of the production system, highlighting the effec-tiveness of spatial data organization.

Highly Scalable Trip Grouping for Large Scale Collective Transportation Systems

DEFF Research Database (Denmark)

Gidofalvi, Gyozo; Pedersen, Torben Bach; Risch, Tore

2008-01-01

Transportation-related problems, like road congestion, parking, and pollution, are increasing in most cities. In order to reduce traffic, recent work has proposed methods for vehicle sharing, for example for sharing cabs by grouping "closeby" cab requests and thus minimizing transportation cost...... and utilizing cab space. However, the methods published so far do not scale to large data volumes, which is necessary to facilitate large-scale collective transportation systems, e.g., ride-sharing systems for large cities. This paper presents highly scalable trip grouping algorithms, which generalize previous...

Evaluating the scalability of HEP software and multi-core hardware

CERN Document Server

Jarp, S; Leduc, J; Nowak, A

2011-01-01

As researchers have reached the practical limits of processor performance improvements by frequency scaling, it is clear that the future of computing lies in the effective utilization of parallel and multi-core architectures. Since this significant change in computing is well underway, it is vital for HEP programmers to understand the scalability of their software on modern hardware and the opportunities for potential improvements. This work aims to quantify the benefit of new mainstream architectures to the HEP community through practical benchmarking on recent hardware solutions, including the usage of parallelized HEP applications.

Scalable and Hybrid Radio Resource Management for Future Wireless Networks

DEFF Research Database (Denmark)

Mino, E.; Luo, Jijun; Tragos, E.

2007-01-01

The concept of ubiquitous and scalable system is applied in the IST WINNER II [1] project to deliver optimum performance for different deployment scenarios, from local area to wide area wireless networks. The integration in a unique radio system of a cellular and local area type networks supposes...... a great advantage for the final user and for the operator, compared with the current situation, with disconnected systems, usually with different subscriptions, radio interfaces and terminals. To be a ubiquitous wireless system, the IST project WINNER II has defined three system modes. This contribution...

NASA Product Peer Review Process

Science.gov (United States)

Jenks, Ken

2009-01-01

This viewgraph presentation describes NASA's product peer review process. The contents include: 1) Inspection/Peer Review at NASA; 2) Reasons for product peer reviews; 3) Different types of peer reviews; and 4) NASA requirements for peer reviews. This presentation also includes a demonstration of an actual product peer review.

Design and implementation of scalable IPv4-IPv6 internetworking gateway

Science.gov (United States)

Zhu, Guo-sheng; Yu, Shao-hua; Dai, Jin-you

2008-11-01

This paper proposed a scalable architecture of IPv4-IPv6 internetworking gateway based on EZchip 10Gbps network processor NP-1c. The Application Layer Gateway(ALG) of control plane can be upgraded without needing to modify the data forwarding plane.A SIP ALG of 3GPP IMS(IP Multimedia Subsystem)was implemented and tested under real China Next Generation Internet(CNGI) network environment.IPv4 SIP UEs can communicate with IPv6 SIP UEs through the gateway.

New approach for sustaining energetic, efficient and scalable non-equilibrium plasma in water vapours at atmospheric pressure

International Nuclear Information System (INIS)

Malik, Muhammad Arif; Schoenbach, Karl H

2012-01-01

Energetic and scalable non-equilibrium plasma was formed in pure water vapour at atmospheric pressure between wire-to-strip electrodes on a dielectric surface with one of the electrodes extended forming a conductive plane on the back side of the dielectric surface. The energy deposition increased by an order of magnitude compared with the conventional pulsed corona discharges under the same conditions. The scalability was demonstrated by operating two electrode assemblies with a common conductive plane between two dielectric layers. The energy yields for hydrogen and hydrogen peroxide generation were measured as ∼1.2 g H 2 /kWh and ∼4 g H 2 O 2 /kWh. (fast track communication)

Enhancing the Impact of NASA Astrophysics Education and Public Outreach: Using Real NASA Data in the Classroom

Science.gov (United States)

Lawton, Brandon L.; Smith, D. A.; SMD Astrophysics E/PO Community, NASA

2013-01-01

The NASA Science Education and Public Outreach Forums support the NASA Science Mission Directorate (SMD) and its education and public outreach (E/PO) community in enhancing the coherence, efficiency, and effectiveness of SMD-funded E/PO programs. As a part of this effort, the Astrophysics Forum is coordinating a collaborative project among the NASA SMD astrophysics missions and E/PO programs to create a broader impact for the use of real NASA data in classrooms. Among NASA's major education goals is the training of students in the Science, Technology, Engineering, and Math (STEM) disciplines. The use of real data, from some of the most sophisticated observatories in the world, provide educators an authentic opportunity to teach students basic science process skills, inquiry, and real-world applications of the STEM subjects. The goal of this NASA SMD astrophysics community collaboration is to find a way to maximize the reach of existing real data products produced by E/PO professionals working with NASA E/PO grants and missions in ways that enhance the teaching of the STEM subjects. We present an initial result of our collaboration: defining levels of basic science process skills that lie at the heart of authentic scientific research and national education standards (AAAS Benchmarks) and examples of NASA data products that align with those levels. Our results are the beginning of a larger goal of utilizing the new NASA education resource catalog, NASA Wavelength, for the creation of progressions that tie NASA education resources together. We aim to create an informational sampler that illustrates how an educator can use the NASA Wavelength resource catalog to connect NASA real-data resources that meet the educational goals of their class.

Final Report. Center for Scalable Application Development Software

Energy Technology Data Exchange (ETDEWEB)

Mellor-Crummey, John [Rice Univ., Houston, TX (United States)

2014-10-26

The Center for Scalable Application Development Software (CScADS) was established as a part- nership between Rice University, Argonne National Laboratory, University of California Berkeley, University of Tennessee – Knoxville, and University of Wisconsin – Madison. CScADS pursued an integrated set of activities with the aim of increasing the productivity of DOE computational scientists by catalyzing the development of systems software, libraries, compilers, and tools for leadership computing platforms. Principal Center activities were workshops to engage the research community in the challenges of leadership computing, research and development of open-source software, and work with computational scientists to help them develop codes for leadership computing platforms. This final report summarizes CScADS activities at Rice University in these areas.

Sharing NASA Science with Decision Makers: A Perspective from NASA's Applied Remote Sensing Training (ARSET) Program

Science.gov (United States)

Prados, A. I.; Blevins, B.; Hook, E.

2015-12-01

NASA ARSET http://arset.gsfc.nasa.gov has been providing applied remote sensing training since 2008. The goals of the program are to develop the technical and analytical skills necessary to utilize NASA resources for decision-support. The program has reached over 3500 participants, with 1600 stakeholders from 100 countries in 2015 alone. The target audience for the program are professionals engaged in environmental management in the public and private sectors, such as air quality forecasters, public utilities, water managers and non-governmental organizations engaged in conservation. Many program participants have little or no expertise in NASA remote sensing, and it's frequently their very first exposure to NASA's vast resources. One the key challenges for the program has been the evolution and refinement of its approach to communicating NASA data access, research, and ultimately its value to stakeholders. We discuss ARSET's best practices for sharing NASA science, which include 1) training ARSET staff and other NASA scientists on methods for science communication, 2) communicating the proper amount of scientific information at a level that is commensurate with the technical skills of program participants, 3) communicating the benefit of NASA resources to stakeholders, and 4) getting to know the audience and tailoring the message so that science information is conveyed within the context of agencies' unique environmental challenges.

NASA IMAGESEER: NASA IMAGEs for Science, Education, Experimentation and Research

Science.gov (United States)

Le Moigne, Jacqueline; Grubb, Thomas G.; Milner, Barbara C.

2012-01-01

A number of web-accessible databases, including medical, military or other image data, offer universities and other users the ability to teach or research new Image Processing techniques on relevant and well-documented data. However, NASA images have traditionally been difficult for researchers to find, are often only available in hard-to-use formats, and do not always provide sufficient context and background for a non-NASA Scientist user to understand their content. The new IMAGESEER (IMAGEs for Science, Education, Experimentation and Research) database seeks to address these issues. Through a graphically-rich web site for browsing and downloading all of the selected datasets, benchmarks, and tutorials, IMAGESEER provides a widely accessible database of NASA-centric, easy to read, image data for teaching or validating new Image Processing algorithms. As such, IMAGESEER fosters collaboration between NASA and research organizations while simultaneously encouraging development of new and enhanced Image Processing algorithms. The first prototype includes a representative sampling of NASA multispectral and hyperspectral images from several Earth Science instruments, along with a few small tutorials. Image processing techniques are currently represented with cloud detection, image registration, and map cover/classification. For each technique, corresponding data are selected from four different geographic regions, i.e., mountains, urban, water coastal, and agriculture areas. Satellite images have been collected from several instruments - Landsat-5 and -7 Thematic Mappers, Earth Observing-1 (EO-1) Advanced Land Imager (ALI) and Hyperion, and the Moderate Resolution Imaging Spectroradiometer (MODIS). After geo-registration, these images are available in simple common formats such as GeoTIFF and raw formats, along with associated benchmark data.

Empirical Evaluation of Superposition Coded Multicasting for Scalable Video

KAUST Repository

Chun Pong Lau

2013-03-01

In this paper we investigate cross-layer superposition coded multicast (SCM). Previous studies have proven its effectiveness in exploiting better channel capacity and service granularities via both analytical and simulation approaches. However, it has never been practically implemented using a commercial 4G system. This paper demonstrates our prototype in achieving the SCM using a standard 802.16 based testbed for scalable video transmissions. In particular, to implement the superposition coded (SPC) modulation, we take advantage a novel software approach, namely logical SPC (L-SPC), which aims to mimic the physical layer superposition coded modulation. The emulation results show improved throughput comparing with generic multicast method.

The Digital Learning Transition MOOC for Educators: Exploring a Scalable Approach to Professional Development

Science.gov (United States)

Kleiman, Glenn M.; Wolf, Mary Ann; Frye, David

2013-01-01

In conjunction with the relaunch of the Digital Learning Transition (DLT) Massive Open Online Course for Educatos (MOOC-Ed) in September 2013, the Alliance and the Friday Institute released "The Digital Learning Transition MOOC for Educators: Exploring a Scalable Approach to Professional Development", a new paper that describes the…

Implementing NASA's Capability-Driven Approach: Insight into NASA's Processes for Maturing Exploration Systems

Science.gov (United States)

Williams-Byrd, Julie; Arney, Dale; Rodgers, Erica; Antol, Jeff; Simon, Matthew; Hay, Jason; Larman, Kevin

2015-01-01

NASA is engaged in transforming human spaceflight. The Agency is shifting from an exploration-based program with human activities focused on low Earth orbit (LEO) and targeted robotic missions in deep space to a more sustainable and integrated pioneering approach. Through pioneering, NASA seeks to address national goals to develop the capacity for people to work, learn, operate, live, and thrive safely beyond the Earth for extended periods of time. However, pioneering space involves more than the daunting technical challenges of transportation, maintaining health, and enabling crew productivity for long durations in remote, hostile, and alien environments. This shift also requires a change in operating processes for NASA. The Agency can no longer afford to engineer systems for specific missions and destinations and instead must focus on common capabilities that enable a range of destinations and missions. NASA has codified a capability driven approach, which provides flexible guidance for the development and maturation of common capabilities necessary for human pioneers beyond LEO. This approach has been included in NASA policy and is captured in the Agency's strategic goals. It is currently being implemented across NASA's centers and programs. Throughout 2014, NASA engaged in an Agency-wide process to define and refine exploration-related capabilities and associated gaps, focusing only on those that are critical for human exploration beyond LEO. NASA identified 12 common capabilities ranging from Environmental Control and Life Support Systems to Robotics, and established Agency-wide teams or working groups comprised of subject matter experts that are responsible for the maturation of these exploration capabilities. These teams, called the System Maturation Teams (SMTs) help formulate, guide and resolve performance gaps associated with the identified exploration capabilities. The SMTs are defining performance parameters and goals for each of the 12 capabilities

Chemical Engineering at NASA

Science.gov (United States)

Collins, Jacob

2008-01-01

This viewgraph presentation is a review of the career paths for chemicals engineer at NASA (specifically NASA Johnson Space Center.) The author uses his personal experience and history as an example of the possible career options.

Using Docker Containers to Extend Reproducibility Architecture for the NASA Earth Exchange (NEX)

Science.gov (United States)

Votava, Petr; Michaelis, Andrew; Spaulding, Ryan; Becker, Jeffrey C.

2016-01-01

believe this is an important step towards seamless process deployment in heterogeneous environments that will enhance community access to NASA data and tools in a scalable way, promote software reuse, and improve reproducibility of scientific results.

A scalable quantum computer with ions in an array of microtraps

Science.gov (United States)

Cirac; Zoller

2000-04-06

Quantum computers require the storage of quantum information in a set of two-level systems (called qubits), the processing of this information using quantum gates and a means of final readout. So far, only a few systems have been identified as potentially viable quantum computer models--accurate quantum control of the coherent evolution is required in order to realize gate operations, while at the same time decoherence must be avoided. Examples include quantum optical systems (such as those utilizing trapped ions or neutral atoms, cavity quantum electrodynamics and nuclear magnetic resonance) and solid state systems (using nuclear spins, quantum dots and Josephson junctions). The most advanced candidates are the quantum optical and nuclear magnetic resonance systems, and we expect that they will allow quantum computing with about ten qubits within the next few years. This is still far from the numbers required for useful applications: for example, the factorization of a 200-digit number requires about 3,500 qubits, rising to 100,000 if error correction is implemented. Scalability of proposed quantum computer architectures to many qubits is thus of central importance. Here we propose a model for an ion trap quantum computer that combines scalability (a feature usually associated with solid state proposals) with the advantages of quantum optical systems (in particular, quantum control and long decoherence times).

NASA's Software Safety Standard

Science.gov (United States)

Ramsay, Christopher M.

2007-01-01

NASA relies more and more on software to control, monitor, and verify its safety critical systems, facilities and operations. Since the 1960's there has hardly been a spacecraft launched that does not have a computer on board that will provide command and control services. There have been recent incidents where software has played a role in high-profile mission failures and hazardous incidents. For example, the Mars Orbiter, Mars Polar Lander, the DART (Demonstration of Autonomous Rendezvous Technology), and MER (Mars Exploration Rover) Spirit anomalies were all caused or contributed to by software. The Mission Control Centers for the Shuttle, ISS, and unmanned programs are highly dependant on software for data displays, analysis, and mission planning. Despite this growing dependence on software control and monitoring, there has been little to no consistent application of software safety practices and methodology to NASA's projects with safety critical software. Meanwhile, academia and private industry have been stepping forward with procedures and standards for safety critical systems and software, for example Dr. Nancy Leveson's book Safeware: System Safety and Computers. The NASA Software Safety Standard, originally published in 1997, was widely ignored due to its complexity and poor organization. It also focused on concepts rather than definite procedural requirements organized around a software project lifecycle. Led by NASA Headquarters Office of Safety and Mission Assurance, the NASA Software Safety Standard has recently undergone a significant update. This new standard provides the procedures and guidelines for evaluating a project for safety criticality and then lays out the minimum project lifecycle requirements to assure the software is created, operated, and maintained in the safest possible manner. This update of the standard clearly delineates the minimum set of software safety requirements for a project without detailing the implementation for those

NASA's Bio-Inspired Acoustic Absorber Concept

Science.gov (United States)

Koch, L. Danielle

2017-01-01

Transportation noise pollutes our worlds cities, suburbs, parks, and wilderness areas. NASAs fundamental research in aviation acoustics is helping to find innovative solutions to this multifaceted problem. NASA is learning from nature to develop the next generation of quiet aircraft.The number of road vehicles and airplanes has roughly tripled since the 1960s. Transportation noise is audible in nearly all the counties across the US. Noise can damage your hearing, raise your heart rate and blood pressure, disrupt your sleep, and make communication difficult. Noise pollution threatens wildlife when it prevents animals from hearing prey, predators, and mates. Noise regulations help drive industry to develop quieter aircraft. Noise standards for aircraft have been developed by the International Civil Aviation Organization and adopted by the US Federal Aviation Administration. The US National Park Service is working with the Federal Aviation Administration to try to balance the demand for access to the parks and wilderness areas with preservation of the natural soundscape. NASA is helping by conceptualizing quieter, more efficient aircraft of the future and performing the fundamental research to make these concepts a reality someday. Recently, NASA has developed synthetic structures that can absorb sound well over a wide frequency range, and particularly below 1000 Hz, and which mimic the acoustic performance of bundles of natural reeds. We are adapting these structures to control noise on aircraft, and spacecraft. This technology might be used in many other industrial or architectural applications where acoustic absorbers have tight constraints on weight and thickness, and may be exposed to high temperatures or liquids. Information about this technology is being made available through reports and presentations available through the NASA Technical Report Server, http:ntrs.nasa.gov. Organizations who would like to collaborate with NASA or commercialize NASAs technology

Scalable 3D bicontinuous fluid networks: polymer heat exchangers toward artificial organs.

Science.gov (United States)

Roper, Christopher S; Schubert, Randall C; Maloney, Kevin J; Page, David; Ro, Christopher J; Yang, Sophia S; Jacobsen, Alan J

2015-04-17

A scalable method for fabricating architected materials well-suited for heat and mass exchange is presented. These materials exhibit unprecedented combinations of small hydraulic diameters (13.0-0.09 mm) and large hydraulic-diameter-to-thickness ratios (5.0-30,100). This process expands the range of material architectures achievable starting from photopolymer waveguide lattices or additive manufacturing. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

All-optical packet/circuit switching-based data center network for enhanced scalability, latency and throughput

NARCIS (Netherlands)

Perelló, J.; Spadaro, S.; Ricciardi, S.; Careglio, D.; Peng, S.; Nejabati, R.; Zervas, G.; Simeonidou, D.; Predieri, A.; Biancani, M.; Dorren, H.J.S.; Di Lucente, S.; Luo, J.; Calabretta, N.; Bernini, G.; Ciulli, N.; Sancho, J.C.; Iordache, S.; Farreras, M.; Becerra, Y.; Liou, C.; Hussain, I.; Yin, Y.; Liu, L.; Proietti, R.

2013-01-01

Applications running inside data centers are enabled through the cooperation of thousands of servers arranged in racks and interconnected together through the data center network. Current DCN architectures based on electronic devices are neither scalable to face the massive growth of DCs, nor

Scalable inference for stochastic block models

KAUST Repository

Peng, Chengbin

2017-12-08

Community detection in graphs is widely used in social and biological networks, and the stochastic block model is a powerful probabilistic tool for describing graphs with community structures. However, in the era of "big data," traditional inference algorithms for such a model are increasingly limited due to their high time complexity and poor scalability. In this paper, we propose a multi-stage maximum likelihood approach to recover the latent parameters of the stochastic block model, in time linear with respect to the number of edges. We also propose a parallel algorithm based on message passing. Our algorithm can overlap communication and computation, providing speedup without compromising accuracy as the number of processors grows. For example, to process a real-world graph with about 1.3 million nodes and 10 million edges, our algorithm requires about 6 seconds on 64 cores of a contemporary commodity Linux cluster. Experiments demonstrate that the algorithm can produce high quality results on both benchmark and real-world graphs. An example of finding more meaningful communities is illustrated consequently in comparison with a popular modularity maximization algorithm.

NASA University Program Management Information System

Science.gov (United States)

1999-01-01

As basic policy, NASA believes that colleges and universities should be encouraged to participate in the nation's space and aeronautics program to the maximum extent practicable. Indeed, universities are considered as partners with government and industry in the nation's aerospace program. NASA's objective is to have them bring their scientific, engineering, and social research competence to bear on aerospace problems and on the broader social, economic, and international implications of NASA's technical and scientific programs. It is expected that, in so doing, universities will strengthen both their research and their educational capabilities to contribute more effectively to the national well-being. NASA field codes and certain Headquarters program offices provide funds for those activities in universities which contribute to the mission needs of that particular NASA element. Although NASA has no predetermined amount of money to devote to university activities, the effort funded each year is substantial. (See the bar chart on the next page). This annual report is one means of documenting the NASA-university relationship, frequently denoted, collectively, as NASA's University Program. This report is consistent with agency accounting records, as the data is obtained from NASA's Financial and Contractual Status (FACS) System, operated by the Financial Management Division and the Procurement Office. However, in accordance with interagency agreements, the orientation differs from that required for financial or procurement purposes. Any apparent discrepancies between this report and other NASA procurement or financial reports stem from the selection criteria for the data.

BASSET: Scalable Gateway Finder in Large Graphs

Energy Technology Data Exchange (ETDEWEB)

Tong, H; Papadimitriou, S; Faloutsos, C; Yu, P S; Eliassi-Rad, T

2010-11-03

Given a social network, who is the best person to introduce you to, say, Chris Ferguson, the poker champion? Or, given a network of people and skills, who is the best person to help you learn about, say, wavelets? The goal is to find a small group of 'gateways': persons who are close enough to us, as well as close enough to the target (person, or skill) or, in other words, are crucial in connecting us to the target. The main contributions are the following: (a) we show how to formulate this problem precisely; (b) we show that it is sub-modular and thus it can be solved near-optimally; (c) we give fast, scalable algorithms to find such gateways. Experiments on real data sets validate the effectiveness and efficiency of the proposed methods, achieving up to 6,000,000x speedup.

A Scalable Parallel PWTD-Accelerated SIE Solver for Analyzing Transient Scattering from Electrically Large Objects

KAUST Repository

Liu, Yang

2015-12-17

A scalable parallel plane-wave time-domain (PWTD) algorithm for efficient and accurate analysis of transient scattering from electrically large objects is presented. The algorithm produces scalable communication patterns on very large numbers of processors by leveraging two mechanisms: (i) a hierarchical parallelization strategy to evenly distribute the computation and memory loads at all levels of the PWTD tree among processors, and (ii) a novel asynchronous communication scheme to reduce the cost and memory requirement of the communications between the processors. The efficiency and accuracy of the algorithm are demonstrated through its applications to the analysis of transient scattering from a perfect electrically conducting (PEC) sphere with a diameter of 70 wavelengths and a PEC square plate with a dimension of 160 wavelengths. Furthermore, the proposed algorithm is used to analyze transient fields scattered from realistic airplane and helicopter models under high frequency excitation.

NASA UAS Update

Science.gov (United States)

Bauer, Jeffrey Ervin; Mulac, Brenda Lynn

2010-01-01

Last year may prove to be a pivotal year for the National Aeronautics and Space Administration (NASA) in the Unmanned Aircraft Systems (UAS) arena, especially in relation to routine UAS access to airspace as NASA accepted an invitation to join the UAS Executive Committee (UAS ExCom). The UAS ExCom is a multi-agency, Federal executive-level committee comprised of the Federal Aviation Administration (FAA), Department of Defense (DoD), Department of Homeland Security (DHS), and NASA with the goals to: 1) Coordinate and align efforts between key Federal Government agencies to achieve routine safe federal public UAS operations in the National Airspace System (NAS); 2) Coordinate and prioritize technical, procedural, regulatory, and policy solutions needed to deliver incremental capabilities; 3) Develop a plan to accommodate the larger stakeholder community at the appropriate time; and 4) Resolve conflicts between Federal Government agencies (FAA, DoD, DHS, and NASA), related to the above goals. The committee was formed in recognition of the need of UAS operated by these agencies to access to the National Airspace System (NAS) to support operational, training, development and research requirements. In order to meet that need, technical, procedural, regulatory, and policy solutions are required to deliver incremental capabilities leading to routine access. The formation of the UAS ExCom is significant in that it represents a tangible commitment by FAA senior leadership to address the UAS access challenge. While the focus of the ExCom is government owned and operated UAS, civil UAS operations are bound to benefit by the progress made in achieving routine access for government UAS. As the UAS ExCom was forming, NASA's Aeronautics Research Mission Directorate began to show renewed interest in UAS, particularly in relation to the future state of the air transportation system under the Next Generation Air Transportation System (NextGen). NASA made funding from the American

NASA tire/runway friction projects

Science.gov (United States)

Yager, Thomas J.

1995-01-01

The paper reviews several aspects of NASA Langley Research Center's tire/runway friction evaluations directed towards improving the safety and economy of aircraft ground operations. The facilities and test equipment used in implementing different aircraft tire friction studies and other related aircraft ground performance investigations are described together with recent workshop activities at NASA Wallops Flight Facility. An overview of the pending Joint NASA/Transport Canada/FM Winter Runway Friction Program is given. Other NASA ongoing studies and on-site field tests are discussed including tire wear performance and new surface treatments. The paper concludes with a description of future research plans.

Flexible Electronics Development Supported by NASA

Science.gov (United States)

Baumann, Eric

2014-01-01

The commercial electronics industry is leading development in most areas of electronics for NASA applications; however, working in partnership with industry and the academic community, results from NASA research could lead to better understanding and utilization of electronic materials by the flexible electronics industry. Innovative ideas explored by our partners in industry and the broader U.S. research community help NASA execute our missions and bring new American products and services to the global technology marketplace. [Mike Gazarik, associate administrator for Space Technology, NASA Headquarters, Washington DC] This presentation provides information on NASA needs in electronics looking towards the future, some of the work being supported by NASA in flexible electronics, and the capabilities of the Glenn Research Center supporting the development of flexible electronics.

NASA as a Convener: Government, Academic and Industry Collaborations Through the NASA Human Health and Performance Center

Science.gov (United States)

Davis, Jeffrey R.; Richard, Elizabeth E.

2011-01-01

On October 18, 2010, the NASA Human Health and Performance center (NHHPC) was opened to enable collaboration among government, academic and industry members. Membership rapidly grew to 60 members (http://nhhpc.nasa.gov ) and members began identifying collaborative projects as detailed below. In addition, a first workshop in open collaboration and innovation was conducted on January 19, 2011 by the NHHPC resulting in additional challenges and projects for further development. This first workshop was a result of the SLSD successes in running open innovation challenges over the past two years. In 2008, the NASA Johnson Space Center, Space Life Sciences Directorate (SLSD) began pilot projects in open innovation (crowd sourcing) to determine if these new internet-based platforms could indeed find solutions to difficult technical problems. From 2008 to 2010, the SLSD issued 34 challenges, 14 externally and 20 internally. The 14 external challenges were conducted through three different vendors: InnoCentive, Yet2.com and TopCoder. The 20 internal challenges were conducted using the InnoCentive platform, customized to NASA use, and promoted as NASA@Work. The results from the 34 challenges involved not only technical solutions that were reported previously at the 61st IAC, but also the formation of new collaborative relationships. For example, the TopCoder pilot was expanded by the NASA Space Operations Mission Directorate to the NASA Tournament Lab in collaboration with Harvard Business School and TopCoder. Building on these initial successes, the NHHPC workshop in January of 2011, and ongoing NHHPC member discussions, several important collaborations are in development: Space Act Agreement between NASA and GE for collaborative projects, NASA and academia for a Visual Impairment / Intracranial Hypertension summit (February 2011), NASA and the DoD through the Defense Venture Catalyst Initiative (DeVenCI) for a technical needs workshop (June 2011), NASA and the San Diego Zoo

Scalable fractionation of iron oxide nanoparticles using a CO{sub 2} gas-expanded liquid system

Energy Technology Data Exchange (ETDEWEB)

Vengsarkar, Pranav S.; Xu, Rui; Roberts, Christopher B., E-mail: croberts@eng.auburn.edu [Auburn University, Department of Chemical Engineering (United States)

2015-10-15

Iron oxide nanoparticles exhibit highly size-dependent physicochemical properties that are important in applications such as catalysis and environmental remediation. In order for these size-dependent properties to be effectively harnessed for industrial applications scalable and cost-effective techniques for size-controlled synthesis or size separation must be developed. The synthesis of monodisperse iron oxide nanoparticles can be a prohibitively expensive process on a large scale. An alternative involves the use of inexpensive synthesis procedures followed by a size-selective processing technique. While there are many techniques available to fractionate nanoparticles, many of the techniques are unable to efficiently fractionate iron oxide nanoparticles in a scalable and inexpensive manner. A scalable apparatus capable of fractionating large quantities of iron oxide nanoparticles into distinct fractions of different sizes and size distributions has been developed. Polydisperse iron oxide nanoparticles (2–20 nm) coated with oleic acid used in this study were synthesized using a simple and inexpensive version of the popular coprecipitation technique. This apparatus uses hexane as a CO{sub 2} gas-expanded liquid to controllably precipitate nanoparticles inside a 1L high-pressure reactor. This paper demonstrates the operation of this new apparatus and for the first time shows the successful fractionation results on a system of metal oxide nanoparticles, with initial nanoparticle concentrations in the gram-scale. The analysis of the obtained fractions was performed using transmission electron microscopy and dynamic light scattering. The use of this simple apparatus provides a pathway to separate large quantities of iron oxide nanoparticles based upon their size for use in various industrial applications.

The Virtual Climate Data Server (vCDS): An iRODS-Based Data Management Software Appliance Supporting Climate Data Services and Virtualization-as-a-Service in the NASA Center for Climate Simulation

Science.gov (United States)

Schnase, John L.; Tamkin, Glenn S.; Ripley, W. David III; Stong, Savannah; Gill, Roger; Duffy, Daniel Q.

2012-01-01

Scientific data services are becoming an important part of the NASA Center for Climate Simulation's mission. Our technological response to this expanding role is built around the concept of a Virtual Climate Data Server (vCDS), repetitive provisioning, image-based deployment and distribution, and virtualization-as-a-service. The vCDS is an iRODS-based data server specialized to the needs of a particular data-centric application. We use RPM scripts to build vCDS images in our local computing environment, our local Virtual Machine Environment, NASA s Nebula Cloud Services, and Amazon's Elastic Compute Cloud. Once provisioned into one or more of these virtualized resource classes, vCDSs can use iRODS s federation capabilities to create an integrated ecosystem of managed collections that is scalable and adaptable to changing resource requirements. This approach enables platform- or software-asa- service deployment of vCDS and allows the NCCS to offer virtualization-as-a-service: a capacity to respond in an agile way to new customer requests for data services.

Factors influencing the implementation, adoption, use, sustainability and scalability of eLearning for family medicine specialty training: a systematic review protocol.

Science.gov (United States)

Cotič, Živa; Rees, Rebecca; Wark, Petra A; Car, Josip

2016-10-19

In 2013, there was a shortage of approximately 7.2 million health workers worldwide, which is larger among family physicians than among specialists. eLearning could provide a potential solution to some of these global workforce challenges. However, there is little evidence on factors facilitating or hindering implementation, adoption, use, scalability and sustainability of eLearning. This review aims to synthesise results from qualitative and mixed methods studies to provide insight on factors influencing implementation of eLearning for family medicine specialty education and training. Additionally, this review aims to identify the actions needed to increase effectiveness of eLearning and identify the strategies required to improve eLearning implementation, adoption, use, sustainability and scalability for family medicine speciality education and training. A systematic search will be conducted across a range of databases for qualitative studies focusing on experiences, barriers, facilitators, and other factors related to the implementation, adoption, use, sustainability and scalability of eLearning for family medicine specialty education and training. Studies will be synthesised by using the framework analysis approach. This study will contribute to the evaluation of eLearning implementation, adoption, use, sustainability and scalability for family medicine specialty training and education and the development of eLearning guidelines for postgraduate medical education. PROSPERO http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42016036449.

Technology transfer at NASA - A librarian's view

Science.gov (United States)

Buchan, Ronald L.

1991-01-01

The NASA programs, publications, and services promoting the transfer and utilization of aerospace technology developed by and for NASA are briefly surveyed. Topics addressed include the corporate sources of NASA technical information and its interest for corporate users of information services; the IAA and STAR abstract journals; NASA/RECON, NTIS, and the AIAA Aerospace Database; the RECON Space Commercialization file; the Computer Software Management and Information Center file; company information in the RECON database; and services to small businesses. Also discussed are the NASA publications Tech Briefs and Spinoff, the Industrial Applications Centers, NASA continuing bibliographies on management and patent abstracts (indexed using the NASA Thesaurus), the Index to NASA News Releases and Speeches, and the Aerospace Research Information Network (ARIN).

NASA Guidelines for Promoting Scientific and Research Integrity

Science.gov (United States)

Kaminski, Amy P.; Neogi, Natasha A.

2017-01-01

This guidebook provides an overarching summary of existing policies, activities, and guiding principles for scientific and research integrity with which NASA's workforce and affiliates must conform. This document addresses NASA's obligations as both a research institution and as a funder of research, NASA's use of federal advisory committees, NASA's public communication of research results, and professional development of NASA's workforce. This guidebook is intended to provide a single resource for NASA researchers, NASA research program administrators and project managers, external entities who do or might receive funding from NASA for research or technical projects, evaluators of NASA research proposals, NASA advisory committee members, NASA communications specialists, and members of the general public so that they can understand NASA's commitment to and expectations for scientific and integrity across the agency.

Scalable Parallel Distributed Coprocessor System for Graph Searching Problems with Massive Data

Directory of Open Access Journals (Sweden)

Wanrong Huang

2017-01-01

Full Text Available The Internet applications, such as network searching, electronic commerce, and modern medical applications, produce and process massive data. Considerable data parallelism exists in computation processes of data-intensive applications. A traversal algorithm, breadth-first search (BFS, is fundamental in many graph processing applications and metrics when a graph grows in scale. A variety of scientific programming methods have been proposed for accelerating and parallelizing BFS because of the poor temporal and spatial locality caused by inherent irregular memory access patterns. However, new parallel hardware could provide better improvement for scientific methods. To address small-world graph problems, we propose a scalable and novel field-programmable gate array-based heterogeneous multicore system for scientific programming. The core is multithread for streaming processing. And the communication network InfiniBand is adopted for scalability. We design a binary search algorithm to address mapping to unify all processor addresses. Within the limits permitted by the Graph500 test bench after 1D parallel hybrid BFS algorithm testing, our 8-core and 8-thread-per-core system achieved superior performance and efficiency compared with the prior work under the same degree of parallelism. Our system is efficient not as a special acceleration unit but as a processor platform that deals with graph searching applications.

Energy Efficiency and Scalability of Metallic Nanoparticle Production Using Arc/Spark Discharge

Directory of Open Access Journals (Sweden)

Martin Slotte

2017-10-01

Full Text Available The increased global demand for metallic nanoparticles for an ever growing number of applications has given rise to a need for larger scale and more efficient nanoparticle (NP production processes. In this paper one such process is evaluated from the viewpoints of scalability and energy efficiency. Multiple setups of different scale of an arc/spark process were evaluated for energy efficiency and scalability using exergy analysis, heat loss evaluation and life cycle impact assessment, based on data collected from EU FP7 project partners. The energy efficiency of the process is quite low, with e.g., a specific electricity consumption (SEC of producing ~80 nm copper NP of 180 kWh/kg while the thermodynamic minimum energy need is 0.03 kWh/kg. This is due to thermal energy use characteristics of the system. During scale-up of the process the SEC remained similar to that of smaller setups. Loss of NP mass in the tubing of larger setups gives a lower material yield. The variation in material yield has a significant impact on the life cycle impact for the produced NP in both the Human Health and Ecosystem Quality categories while the impact is smaller in the Global Warming and Resource Depletion categories.

Neuromorphic adaptive plastic scalable electronics: analog learning systems.

Science.gov (United States)

Srinivasa, Narayan; Cruz-Albrecht, Jose

2012-01-01

Decades of research to build programmable intelligent machines have demonstrated limited utility in complex, real-world environments. Comparing their performance with biological systems, these machines are less efficient by a factor of 1 million1 billion in complex, real-world environments. The Systems of Neuromorphic Adaptive Plastic Scalable Electronics (SyNAPSE) program is a multifaceted Defense Advanced Research Projects Agency (DARPA) project that seeks to break the programmable machine paradigm and define a new path for creating useful, intelligent machines. Since real-world systems exhibit infinite combinatorial complexity, electronic neuromorphic machine technology would be preferable in a host of applications, but useful and practical implementations still do not exist. HRL Laboratories LLC has embarked on addressing these challenges, and, in this article, we provide an overview of our project and progress made thus far.

Affordable Development and Demonstration of a Small NTR Engine and Stage: A Preliminary NASA, DOE, and Industry Assessment

Science.gov (United States)

Borowski, Stanley K.; Sefcik, Robert J.; Fittje, James E.; McCurdy, David R.; Qualls, Arthur L.; Schnitzler, Bruce G.; Werner, James E.; Weitzberg, Abraham; Joyner, Claude R.

2015-01-01

The Nuclear Thermal Rocket (NTR) represents the next evolutionary step in cryogenic liquid rocket engines. Deriving its energy from fission of uranium-235 atoms contained within fuel elements that comprise the engine's reactor core, the NTR can generate high thrust at a specific impulse of approx. 900 seconds or more - twice that of today's best chemical rockets. In FY'11, as part of the AISP project, NASA proposed a Nuclear Thermal Propulsion (NTP) effort that envisioned two key activities - "Foundational Technology Development" followed by system-level "Technology Demonstrations". Five near-term NTP activities identified for Foundational Technology Development became the basis for the NCPS project started in FY'12 and funded by NASA's AES program. During Phase 1 (FY'12-14), the NCPS project was focused on (1) Recapturing fuel processing techniques and fabricating partial length "heritage" fuel elements for the two candidate fuel forms identified by NASA and the DOE - NERVA graphite "composite" and the uranium dioxide (UO2) in tungsten "cermet". The Phase 1 effort also included: (2) Engine Conceptual Design; (3) Mission Analysis and Requirements Definition; (4) Identification of Affordable Options for Ground Testing; and (5) Formulation of an Affordable and Sustainable NTP Development Strategy. During FY'14, a preliminary plan for DDT&E was outlined by GRC, the DOE and industry for NASA HQ that involved significant system-level demonstration projects that included GTD tests at the NNSS, followed by a FTD mission. To reduce development costs, the GTD and FTD tests use a small, low thrust (approx. 7.5 or 16.5 klbf) engine. Both engines use graphite composite fuel and a "common" fuel element design that is scalable to higher thrust (approx. 25 klbf) engines by increasing the number of elements in a larger diameter core that can produce greater thermal power output. To keep the FTD mission cost down, a simple "1-burn" lunar flyby mission was considered along with

Scalable fabrication of strongly textured organic semiconductor micropatterns by capillary force lithography.

Science.gov (United States)

Jo, Pil Sung; Vailionis, Arturas; Park, Young Min; Salleo, Alberto

2012-06-26

Strongly textured organic semiconductor micropatterns made of the small molecule dioctylbenzothienobenzothiophene (C(8)-BTBT) are fabricated by using a method based on capillary force lithography (CFL). This technique provides the C(8)-BTBT solution with nucleation sites for directional growth, and can be used as a scalable way to produce high quality crystalline arrays in desired regions of a substrate for OFET applications. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Facile and Scalable Synthesis of Monodispersed Spherical Capsules with a Mesoporous Shell

KAUST Repository

Qi, Genggeng

2010-05-11

Monodispersed HMSs with tunable particle size and shell thickness were successfully synthesized using relatively concentrated polystyrene latex templates and a silica precursor in a weakly basic ethanol/water mixture. The particle size of the capsules can vary from 100 nm to micrometers. These highly engineered monodispersed capsules synthesized by a facile and scalable process may find applications in drug delivery, catalysis, separationm or as biological and chemical microreactors. © 2010 American Chemical Society.

NASA and The Semantic Web

Science.gov (United States)

Ashish, Naveen

2005-01-01

We provide an overview of several ongoing NASA endeavors based on concepts, systems, and technology from the Semantic Web arena. Indeed NASA has been one of the early adopters of Semantic Web Technology and we describe ongoing and completed R&D efforts for several applications ranging from collaborative systems to airspace information management to enterprise search to scientific information gathering and discovery systems at NASA.

Magnetically anisotropic additive for scalable manufacturing of polymer nanocomposite: iron-coated carbon nanotubes

International Nuclear Information System (INIS)

Yamamoto, Namiko; Manohara, Harish; Platzman, Ellen

2016-01-01

Novel nanoparticles additives for polymer nanocomposites were prepared by coating carbon nanotubes (CNTs) with ferromagnetic iron (Fe) layers, so that their micro-structures can be bulk-controlled by external magnetic field application. Application of magnetic fields is a promising, scalable method to deliver bulk amount of nanocomposites while maintaining organized nanoparticle assembly throughout the uncured polymer matrix. In this work, Fe layers (∼18 nm thick) were deposited on CNTs (∼38 nm diameter and ∼50 μm length) to form thin films with high aspect ratio, resulting in a dominance of shape anisotropy and thus high coercivity of ∼50–100 Oe. The Fe-coated CNTs were suspended in water and applied with a weak magnetic field of ∼75 G, and yet preliminary magnetic assembly was confirmed. Our results demonstrate that the fabricated Fe-coated CNTs are magnetically anisotropic and effectively respond to magnetic fields that are ∼10 3 times smaller than other existing work (∼10 5 G). We anticipate this work will pave the way for effective property enhancement and bulk application of CNT–polymer nanocomposites, through controlled micro-structure and scalable manufacturing. (paper)

Scalable interrogation: Eliciting human pheromone responses to deception in a security interview setting.

Science.gov (United States)

Stedmon, Alex W; Eachus, Peter; Baillie, Les; Tallis, Huw; Donkor, Richard; Edlin-White, Robert; Bracewell, Robert

2015-03-01

Individuals trying to conceal knowledge from interrogators are likely to experience raised levels of stress that can manifest itself across biological, physiological, psychological and behavioural factors, providing an opportunity for detection. Using established research paradigms an innovative scalable interrogation was designed in which participants were given a 'token' that represented information they had to conceal from interviewers. A control group did not receive a token and therefore did not have to deceive the investigators. The aim of this investigation was to examine differences between deceivers and truth-tellers across the four factors by collecting data for cortisol levels, sweat samples, heart-rate, respiration, skin temperature, subjective stress ratings and video and audio recordings. The results provided an integrated understanding of responses to interrogation by those actively concealing information and those acting innocently. Of particular importance, the results also suggest, for the first time in an interrogation setting, that stressed individuals may secrete a volatile steroid based marker that could be used for stand-off detection. The findings are discussed in relation to developing a scalable interrogation protocol for future research in this area. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

A Scalable Policy and SNMP Based Network Management Framework

Institute of Scientific and Technical Information of China (English)

LIU Su-ping; DING Yong-sheng

2009-01-01

Traditional SNMP-based network management can not deal with the task of managing large-scaled distributed network,while policy-based management is one of the effective solutions in network and distributed systems management. However,cross-vendor hardware compatibility is one of the limitations in policy-based management. Devices existing in current network mostly support SNMP rather than Common Open Policy Service (COPS) protocol. By analyzing traditional network management and policy-based network management, a scalable network management framework is proposed. It is combined with Internet Engineering Task Force (IETF) framework for policybased management and SNMP-based network management. By interpreting and translating policy decision to SNMP message,policy can be executed in traditional SNMP-based device.

Science@NASA: Direct to People!

Science.gov (United States)

Koczor, Ronald J.; Adams, Mitzi; Gallagher, Dennis; Whitaker, Ann (Technical Monitor)

2002-01-01

Science@NASA is a science communication effort sponsored by NASA's Marshall Space Flight Center. It is the result of a four year research project between Marshall, the University of Florida College of Journalism and Communications and the internet communications company, Bishop Web Works. The goals of Science@NASA are to inform, inspire, and involve people in the excitement of NASA science by bringing that science directly to them. We stress not only the reporting of the facts of a particular topic, but also the context and importance of the research. Science@NASA involves several levels of activity from academic communications research to production of content for 6 websites, in an integrated process involving all phases of production. A Science Communications Roundtable Process is in place that includes scientists, managers, writers, editors, and Web technical experts. The close connection between the scientists and the writers/editors assures a high level of scientific accuracy in the finished products. The websites each have unique characters and are aimed at different audience segments: 1. http://science.nasa.gov. (SNG) Carries stories featuring various aspects of NASA science activity. The site carries 2 or 3 new stories each week in written and audio formats for science-attentive adults. 2. http://liftoff.msfc.nasa.gov. Features stories from SNG that are recast for a high school level audience. J-Track and J-Pass applets for tracking satellites are our most popular product. 3. http://kids. msfc.nasa.gov. This is the Nursemaids site and is aimed at a middle school audience. The NASAKids Club is a new feature at the site. 4. http://www.thursdaysclassroom.com . This site features lesson plans and classroom activities for educators centered around one of the science stories carried on SNG. 5. http://www.spaceweather.com. This site gives the status of solar activity and its interactions with the Earth's ionosphere and magnetosphere.

Scalable UWB photonic generator based on the combination of doublet pulses.

Science.gov (United States)

Moreno, Vanessa; Rius, Manuel; Mora, José; Muriel, Miguel A; Capmany, José

2014-06-30

We propose and experimentally demonstrate a scalable and reconfigurable optical scheme to generate high order UWB pulses. Firstly, various ultra wideband doublets are created through a process of phase-to-intensity conversion by means of a phase modulation and a dispersive media. In a second stage, doublets are combined in an optical processing unit that allows the reconfiguration of UWB high order pulses. Experimental results both in time and frequency domains are presented showing good performance related to the fractional bandwidth and spectral efficiency parameters.

NASA's Coordinated Efforts to Enhance STEM Education: Bringing NASA Science into the Library

Science.gov (United States)

Meinke, B. K.; Thomas, C.; Eyermann, S.; Mitchell, S.; LaConte, K.; Hauck, K.

2015-11-01

Libraries are community-centered, free-access venues serving learners of all ages and backgrounds. Libraries also recognize the importance of science literacy and strive to include science in their programming portfolio. Scientists and educators can partner with local libraries to advance mutual goals of connecting the public to Earth and Space Science. In this interactive Special Interest Group (SIG) discussion, representatives from the NASA Science Mission Directorate (SMD) Education and Public Outreach (EPO) community's library collaborations discussed the opportunities for partnership with public and school libraries; explored the resources, events, and programs available through libraries; explored NASA science programming and professional development opportunities available for librarians; and strategized about the types of support that librarians require to plan and implement programs that use NASA data and resources. We also shared successes, lessons learned, and future opportunities for incorporating NASA science programming into library settings.

NASA Resources for Educators and Public

Science.gov (United States)

Morales, Lester

2012-01-01

A variety of NASA Classroom Activities, Educator Guides, Lithographs, Posters and more are available to Pre ]service and In ]service Educators through Professional Development Workshops. We are here for you to engage, demonstrate, and facilitate the use of educational technologies, the NASA Website, NASA Education Homepage and more! We are here for you to inspire you by providing in-service and pre- service training utilizing NASA curriculum support products. We are here for you to partner with your local, state, and regional educational organizations to better educate ALL! NASA AESP specialists are experienced professional educators, current on education issues and familiar with the curriculum frameworks, educational standards, and systemic architecture of the states they service. These specialists provide engaging and inspiring student presentations and teacher training right at YOUR school at no cost to you! Experience free out-of-this-world interactive learning with NASA's Digital Learning Network. Students of all ages can participate in LIVE events with NASA Experts and Education Specialists. The Exploration Station provides NASA educational programs that introduce the application of Science, Technology, Engineering, & Mathematics, to students. Students participate in a variety of hands-on activities that compliment related topics taught by the classroom teacher. NASA KSC ERC can create Professional Development Workshops for teachers in groups of fifteen or more. Education/Information Specialists also assist educators in developing lessons to meet Sunshine State and national curriculum standards.

Batteries at NASA - Today and Beyond

Science.gov (United States)

Reid, Concha M.

2015-01-01

NASA uses batteries for virtually all of its space missions. Batteries can be bulky and heavy, and some chemistries are more prone to safety issues than others. To meet NASA's needs for safe, lightweight, compact and reliable batteries, scientists and engineers at NASA develop advanced battery technologies that are suitable for space applications and that can satisfy these multiple objectives. Many times, these objectives compete with one another, as the demand for more and more energy in smaller packages dictates that we use higher energy chemistries that are also more energetic by nature. NASA partners with companies and universities, like Xavier University of Louisiana, to pool our collective knowledge and discover innovative technical solutions to these challenges. This talk will discuss a little about NASA's use of batteries and why NASA seeks more advanced chemistries. A short primer on battery chemistries and their chemical reactions is included. Finally, the talk will touch on how the work under the Solid High Energy Lithium Battery (SHELiB) grant to develop solid lithium-ion conducting electrolytes and solid-state batteries can contribute to NASA's mission.

Biophysics of NASA radiation quality factors

International Nuclear Information System (INIS)

Cucinotta, Francis A.

2015-01-01

NASA has implemented new radiation quality factors (QFs) for projecting cancer risks from space radiation exposures to astronauts. The NASA QFs are based on particle track structure concepts with parameters derived from available radiobiology data, and NASA introduces distinct QFs for solid cancer and leukaemia risk estimates. The NASA model was reviewed by the US National Research Council and approved for use by NASA for risk assessment for International Space Station missions and trade studies of future exploration missions to Mars and other destinations. A key feature of the NASA QFs is to represent the uncertainty in the QF assessments and evaluate the importance of the QF uncertainty to overall uncertainties in cancer risk projections. In this article, the biophysical basis for the probability distribution functions representing QF uncertainties was reviewed, and approaches needed to reduce uncertainties were discussed. (author)

Molecular engineering with artificial atoms: designing a material platform for scalable quantum spintronics and photonics

Science.gov (United States)

Doty, Matthew F.; Ma, Xiangyu; Zide, Joshua M. O.; Bryant, Garnett W.

2017-09-01

Self-assembled InAs Quantum Dots (QDs) are often called "artificial atoms" and have long been of interest as components of quantum photonic and spintronic devices. Although there has been substantial progress in demonstrating optical control of both single spins confined to a single QD and entanglement between two separated QDs, the path toward scalable quantum photonic devices based on spins remains challenging. Quantum Dot Molecules, which consist of two closely-spaced InAs QDs, have unique properties that can be engineered with the solid state analog of molecular engineering in which the composition, size, and location of both the QDs and the intervening barrier are controlled during growth. Moreover, applied electric, magnetic, and optical fields can be used to modulate, in situ, both the spin and optical properties of the molecular states. We describe how the unique photonic properties of engineered Quantum Dot Molecules can be leveraged to overcome long-standing challenges to the creation of scalable quantum devices that manipulate single spins via photonics.

Novel flat datacenter network architecture based on scalable and flow-controlled optical switch system.

Science.gov (United States)

Miao, Wang; Luo, Jun; Di Lucente, Stefano; Dorren, Harm; Calabretta, Nicola

2014-02-10

We propose and demonstrate an optical flat datacenter network based on scalable optical switch system with optical flow control. Modular structure with distributed control results in port-count independent optical switch reconfiguration time. RF tone in-band labeling technique allowing parallel processing of the label bits ensures the low latency operation regardless of the switch port-count. Hardware flow control is conducted at optical level by re-using the label wavelength without occupying extra bandwidth, space, and network resources which further improves the performance of latency within a simple structure. Dynamic switching including multicasting operation is validated for a 4 x 4 system. Error free operation of 40 Gb/s data packets has been achieved with only 1 dB penalty. The system could handle an input load up to 0.5 providing a packet loss lower that 10(-5) and an average latency less that 500 ns when a buffer size of 16 packets is employed. Investigation on scalability also indicates that the proposed system could potentially scale up to large port count with limited power penalty.

Percolator: Scalable Pattern Discovery in Dynamic Graphs

Energy Technology Data Exchange (ETDEWEB)

Choudhury, Sutanay; Purohit, Sumit; Lin, Peng; Wu, Yinghui; Holder, Lawrence B.; Agarwal, Khushbu

2018-02-06

We demonstrate Percolator, a distributed system for graph pattern discovery in dynamic graphs. In contrast to conventional mining systems, Percolator advocates efficient pattern mining schemes that (1) support pattern detection with keywords; (2) integrate incremental and parallel pattern mining; and (3) support analytical queries such as trend analysis. The core idea of Percolator is to dynamically decide and verify a small fraction of patterns and their in- stances that must be inspected in response to buffered updates in dynamic graphs, with a total mining cost independent of graph size. We demonstrate a) the feasibility of incremental pattern mining by walking through each component of Percolator, b) the efficiency and scalability of Percolator over the sheer size of real-world dynamic graphs, and c) how the user-friendly GUI of Percolator inter- acts with users to support keyword-based queries that detect, browse and inspect trending patterns. We also demonstrate two user cases of Percolator, in social media trend analysis and academic collaboration analysis, respectively.

The NASA risk management program

International Nuclear Information System (INIS)

Buchbinder, B.; Philipson, L.L.

1989-01-01

This paper reports that the NASA Risk Management Program has been established to ensure the appropriate application of risk-based procedures in support of the elimination, reduction, or acceptance of significant safety risks of concern in NASA. The term appropriate is emphasized, in that the particular procedures applied to each given risk are to reflect its character and prioritized importance, the technological and economic feasibility of its treatment. A number of key documents have been produced in support of this implementation. Databases, risk analysis tools, and risk communication procedures requisite to the execution of the risk management functions also are being developed or documented. Several risk management applications have been made and a comprehensive application to a major new NASA program is underway. This paper summarizes the development and current status of the NASA Risk Management Program. Some principal actions that have been carried out in NASA in consonance with the program are noted particularly, and views are presented on the program's likely future directions

NASA Advanced Supercomputing Facility Expansion

Science.gov (United States)

Thigpen, William W.

2017-01-01

The NASA Advanced Supercomputing (NAS) Division enables advances in high-end computing technologies and in modeling and simulation methods to tackle some of the toughest science and engineering challenges facing NASA today. The name "NAS" has long been associated with leadership and innovation throughout the high-end computing (HEC) community. We play a significant role in shaping HEC standards and paradigms, and provide leadership in the areas of large-scale InfiniBand fabrics, Lustre open-source filesystems, and hyperwall technologies. We provide an integrated high-end computing environment to accelerate NASA missions and make revolutionary advances in science. Pleiades, a petaflop-scale supercomputer, is used by scientists throughout the U.S. to support NASA missions, and is ranked among the most powerful systems in the world. One of our key focus areas is in modeling and simulation to support NASA's real-world engineering applications and make fundamental advances in modeling and simulation methods.

Scalable Database Design of End-Game Model with Decoupled Countermeasure and Threat Information

Science.gov (United States)

2017-11-01

the Army Modular Active Protection System (MAPS) program to provide end-to-end APS modeling and simulation capabilities. The SSES simulation features...research project of scalable database design was initiated in support of SSES modularization efforts with respect to 4 major software components...Iron Curtain KE kinetic energy MAPS Modular Active Protective System OLE DB object linking and embedding database RDB relational database RPG

BAMSI: a multi-cloud service for scalable distributed filtering of massive genome data.

Science.gov (United States)

Ausmees, Kristiina; John, Aji; Toor, Salman Z; Hellander, Andreas; Nettelblad, Carl

2018-06-26

The advent of next-generation sequencing (NGS) has made whole-genome sequencing of cohorts of individuals a reality. Primary datasets of raw or aligned reads of this sort can get very large. For scientific questions where curated called variants are not sufficient, the sheer size of the datasets makes analysis prohibitively expensive. In order to make re-analysis of such data feasible without the need to have access to a large-scale computing facility, we have developed a highly scalable, storage-agnostic framework, an associated API and an easy-to-use web user interface to execute custom filters on large genomic datasets. We present BAMSI, a Software as-a Service (SaaS) solution for filtering of the 1000 Genomes phase 3 set of aligned reads, with the possibility of extension and customization to other sets of files. Unique to our solution is the capability of simultaneously utilizing many different mirrors of the data to increase the speed of the analysis. In particular, if the data is available in private or public clouds - an increasingly common scenario for both academic and commercial cloud providers - our framework allows for seamless deployment of filtering workers close to data. We show results indicating that such a setup improves the horizontal scalability of the system, and present a possible use case of the framework by performing an analysis of structural variation in the 1000 Genomes data set. BAMSI constitutes a framework for efficient filtering of large genomic data sets that is flexible in the use of compute as well as storage resources. The data resulting from the filter is assumed to be greatly reduced in size, and can easily be downloaded or routed into e.g. a Hadoop cluster for subsequent interactive analysis using Hive, Spark or similar tools. In this respect, our framework also suggests a general model for making very large datasets of high scientific value more accessible by offering the possibility for organizations to share the cost of

NASA's computer science research program

Science.gov (United States)

Larsen, R. L.

1983-01-01

Following a major assessment of NASA's computing technology needs, a new program of computer science research has been initiated by the Agency. The program includes work in concurrent processing, management of large scale scientific databases, software engineering, reliable computing, and artificial intelligence. The program is driven by applications requirements in computational fluid dynamics, image processing, sensor data management, real-time mission control and autonomous systems. It consists of university research, in-house NASA research, and NASA's Research Institute for Advanced Computer Science (RIACS) and Institute for Computer Applications in Science and Engineering (ICASE). The overall goal is to provide the technical foundation within NASA to exploit advancing computing technology in aerospace applications.

Scalable fabrication of self-aligned graphene transistors and circuits on glass.

Science.gov (United States)

Liao, Lei; Bai, Jingwei; Cheng, Rui; Zhou, Hailong; Liu, Lixin; Liu, Yuan; Huang, Yu; Duan, Xiangfeng

2012-06-13

Graphene transistors are of considerable interest for radio frequency (rf) applications. High-frequency graphene transistors with the intrinsic cutoff frequency up to 300 GHz have been demonstrated. However, the graphene transistors reported to date only exhibit a limited extrinsic cutoff frequency up to about 10 GHz, and functional graphene circuits demonstrated so far can merely operate in the tens of megahertz regime, far from the potential the graphene transistors could offer. Here we report a scalable approach to fabricate self-aligned graphene transistors with the extrinsic cutoff frequency exceeding 50 GHz and graphene circuits that can operate in the 1-10 GHz regime. The devices are fabricated on a glass substrate through a self-aligned process by using chemical vapor deposition (CVD) grown graphene and a dielectrophoretic assembled nanowire gate array. The self-aligned process allows the achievement of unprecedented performance in CVD graphene transistors with a highest transconductance of 0.36 mS/μm. The use of an insulating substrate minimizes the parasitic capacitance and has therefore enabled graphene transistors with a record-high extrinsic cutoff frequency (> 50 GHz) achieved to date. The excellent extrinsic cutoff frequency readily allows configuring the graphene transistors into frequency doubling or mixing circuits functioning in the 1-10 GHz regime, a significant advancement over previous reports (∼20 MHz). The studies open a pathway to scalable fabrication of high-speed graphene transistors and functional circuits and represent a significant step forward to graphene based radio frequency devices.

NASA Unmanned Aircraft (UA) Control and Non-Payload Communication (CNPC) System Waveform Trade Studies

Science.gov (United States)

Chavez, Carlos; Hammel, Bruce; Hammel, Allan; Moore, John R.

2014-01-01

Unmanned Aircraft Systems (UAS) represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the National Airspace System (NAS). To address this deficiency, NASA has established a project called UAS Integration in the NAS (UAS in the NAS), under the Integrated Systems Research Program (ISRP) of the Aeronautics Research Mission Directorate (ARMD). This project provides an opportunity to transition concepts, technology, algorithms, and knowledge to the Federal Aviation Administration (FAA) and other stakeholders to help them define the requirements, regulations, and issues for routine UAS access to the NAS. The safe, routine, and efficient integration of UAS into the NAS requires new radio frequency (RF) spectrum allocations and a new data communications system which is both secure and scalable with increasing UAS traffic without adversely impacting the Air Traffic Control (ATC) communication system. These data communications, referred to as Control and Non-Payload Communications (CNPC), whose purpose is to exchange information between the unmanned aircraft and the ground control station to ensure safe, reliable, and effective unmanned aircraft flight operation. A Communications Subproject within the UAS in the NAS Project has been established to address issues related to CNPC development, certification and fielding. The focus of the Communications Subproject is on validating and allocating new RF spectrum and data link communications to enable civil UAS integration into the NAS. The goal is to validate secure, robust data links within the allocated frequency spectrum for UAS. A vision, architectural concepts, and seed requirements for the future commercial UAS CNPC system have been developed by RTCA Special Committee 203 (SC-203) in the process

NASA's Applied Sciences for Water Resources

Science.gov (United States)

Doorn, Bradley; Toll, David; Engman, Ted

2011-01-01

The Earth Systems Division within NASA has the primary responsibility for the Earth Science Applied Science Program and the objective to accelerate the use of NASA science results in applications to help solve problems important to society and the economy. The primary goal of the Earth Science Applied Science Program is to improve future and current operational systems by infusing them with scientific knowledge of the Earth system gained through space-based observation, assimilation of new observations, and development and deployment of enabling technologies, systems, and capabilities. This paper discusses one of the major problems facing water resources managers, that of having timely and accurate data to drive their decision support tools. It then describes how NASA?s science and space based satellites may be used to overcome this problem. Opportunities for the water resources community to participate in NASA?s Water Resources Applications Program are described.

NASA Engineering Safety Center NASA Aerospace Flight Battery Systems Working Group 2007 Proactive Task Status

Science.gov (United States)

Manzo, Michelle A.

2007-01-01

In 2007, the NASA Engineering Safety Center (NESC) chartered the NASA Aerospace Flight Battery Systems Working Group to bring forth and address critical battery-related performance/manufacturing issues for NASA and the aerospace community. A suite of tasks identifying and addressing issues related to Ni-H2 and Li-ion battery chemistries was submitted and selected for implementation. The current NESC funded are: (1) Wet Life of Ni-H2 Batteries (2) Binding Procurement (3) NASA Lithium-Ion Battery Guidelines (3a) Li-Ion Performance Assessment (3b) Li-Ion Guidelines Document (3b-i) Assessment of Applicability of Pouch Cells for Aerospace Missions (3b-ii) High Voltage Risk Assessment (3b-iii) Safe Charge Rates for Li-Ion Cells (4) Availability of Source Material for Li-Ion Cells (5) NASA Aerospace Battery Workshop This presentation provides a brief overview of the tasks in the 2007 plan and serves as an introduction to more detailed discussions on each of the specific tasks.

NASA directives master list and index

Science.gov (United States)

1995-01-01

This handbook sets forth in two parts, Master List of Management Directives and Index to NASA Management Directives, the following information for the guidance of users of the NASA Management Directives System. Chapter 1 contains introductory information material on how to use this handbook. Chapter 2 is a complete master list of agencywide management directives, describing each directive by type, number, effective date, expiration date, title, and organization code of the office responsible for the directive. Chapter 3 includes a consolidated numerical list of all delegations of authority and a breakdown of such delegation by the office or center to which special authority is assigned. Chapter 4 sets forth a consolidated list of all NASA handbooks (NHB's) and important footnotes covering the control and ordering of such documents. Chapter 5 is a consolidated list of NASA management directives applicable to the Jet Propulsion Laboratory. Chapter 6 is a consolidated list of NASA regulations published in the Code of Federal Regulations. Chapter 7 is a consolidated list of NASA regulations published in Title 14 of the Code of Federal Regulations. Complementary manuals to the NASA Management Directives System are described in Chapter 8. The second part contains an in depth alphabetical index to all NASA management directives other than handbooks, most of which are indexed by titles only.

NASA Systems Engineering Handbook

Science.gov (United States)

Hirshorn, Steven R.; Voss, Linda D.; Bromley, Linda K.

2017-01-01

The update of this handbook continues the methodology of the previous revision: a top-down compatibility with higher level Agency policy and a bottom-up infusion of guidance from the NASA practitioners in the field. This approach provides the opportunity to obtain best practices from across NASA and bridge the information to the established NASA systems engineering processes and to communicate principles of good practice as well as alternative approaches rather than specify a particular way to accomplish a task. The result embodied in this handbook is a top-level implementation approach on the practice of systems engineering unique to NASA. Material used for updating this handbook has been drawn from many sources, including NPRs, Center systems engineering handbooks and processes, other Agency best practices, and external systems engineering textbooks and guides. This handbook consists of six chapters: (1) an introduction, (2) a systems engineering fundamentals discussion, (3) the NASA program project life cycles, (4) systems engineering processes to get from a concept to a design, (5) systems engineering processes to get from a design to a final product, and (6) crosscutting management processes in systems engineering. The chapters are supplemented by appendices that provide outlines, examples, and further information to illustrate topics in the chapters. The handbook makes extensive use of boxes and figures to define, refine, illustrate, and extend concepts in the chapters.

Scalable printed electronics: an organic decoder addressing ferroelectric non-volatile memory

Science.gov (United States)

Ng, Tse Nga; Schwartz, David E.; Lavery, Leah L.; Whiting, Gregory L.; Russo, Beverly; Krusor, Brent; Veres, Janos; Bröms, Per; Herlogsson, Lars; Alam, Naveed; Hagel, Olle; Nilsson, Jakob; Karlsson, Christer

2012-01-01

Scalable circuits of organic logic and memory are realized using all-additive printing processes. A 3-bit organic complementary decoder is fabricated and used to read and write non-volatile, rewritable ferroelectric memory. The decoder-memory array is patterned by inkjet and gravure printing on flexible plastics. Simulation models for the organic transistors are developed, enabling circuit designs tolerant of the variations in printed devices. We explain the key design rules in fabrication of complex printed circuits and elucidate the performance requirements of materials and devices for reliable organic digital logic. PMID:22900143

Monte Carlo tests of the Rasch model based on scalability coefficients

DEFF Research Database (Denmark)

Christensen, Karl Bang; Kreiner, Svend

2010-01-01

that summarizes the number of Guttman errors in the data matrix. These coefficients are shown to yield efficient tests of the Rasch model using p-values computed using Markov chain Monte Carlo methods. The power of the tests of unequal item discrimination, and their ability to distinguish between local dependence......For item responses fitting the Rasch model, the assumptions underlying the Mokken model of double monotonicity are met. This makes non-parametric item response theory a natural starting-point for Rasch item analysis. This paper studies scalability coefficients based on Loevinger's H coefficient...

A scalable and practical one-pass clustering algorithm for recommender system

Science.gov (United States)

Khalid, Asra; Ghazanfar, Mustansar Ali; Azam, Awais; Alahmari, Saad Ali

2015-12-01

KMeans clustering-based recommendation algorithms have been proposed claiming to increase the scalability of recommender systems. One potential drawback of these algorithms is that they perform training offline and hence cannot accommodate the incremental updates with the arrival of new data, making them unsuitable for the dynamic environments. From this line of research, a new clustering algorithm called One-Pass is proposed, which is a simple, fast, and accurate. We show empirically that the proposed algorithm outperforms K-Means in terms of recommendation and training time while maintaining a good level of accuracy.

Applications of Scalable Multipoint Video and Audio Using the Public Internet

Directory of Open Access Journals (Sweden)

Robert D. Gaglianello

2000-01-01

Full Text Available This paper describes a scalable multipoint video system, designed for efficient generation and display of high quality, multiple resolution, multiple compressed video streams over IP-based networks. We present our experiences using the system over the public Internet for several “real-world” applications, including distance learning, virtual theater, and virtual collaboration. The trials were a combined effort of Bell Laboratories and the Gertrude Stein Repertory Theatre (TGSRT. We also present current advances in the conferencing system since the trials, new areas for application and future applications.

Performance and scalability of finite-difference and finite-element wave-propagation modeling on Intel's Xeon Phi

NARCIS (Netherlands)

Zhebel, E.; Minisini, S.; Kononov, A.; Mulder, W.A.

2013-01-01

With the rapid developments in parallel compute architectures, algorithms for seismic modeling and imaging need to be reconsidered in terms of parallelization. The aim of this paper is to compare scalability of seismic modeling algorithms: finite differences, continuous mass-lumped finite elements

48 CFR 1842.271 - NASA clause.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true NASA clause. 1842.271 Section 1842.271 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION... NASA clause. Insert the clause at 1852.242-70, Technical Direction, when paragraph 3(m) of the NASA...

Biophysics of NASA radiation quality factors.

Science.gov (United States)

Cucinotta, Francis A

2015-09-01

NASA has implemented new radiation quality factors (QFs) for projecting cancer risks from space radiation exposures to astronauts. The NASA QFs are based on particle track structure concepts with parameters derived from available radiobiology data, and NASA introduces distinct QFs for solid cancer and leukaemia risk estimates. The NASA model was reviewed by the US National Research Council and approved for use by NASA for risk assessment for International Space Station missions and trade studies of future exploration missions to Mars and other destinations. A key feature of the NASA QFs is to represent the uncertainty in the QF assessments and evaluate the importance of the QF uncertainty to overall uncertainties in cancer risk projections. In this article, the biophysical basis for the probability distribution functions representing QF uncertainties was reviewed, and approaches needed to reduce uncertainties were discussed. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

NASA's Internal Space Weather Working Group

Science.gov (United States)

St. Cyr, O. C.; Guhathakurta, M.; Bell, H.; Niemeyer, L.; Allen, J.

2011-01-01

Measurements from many of NASA's scientific spacecraft are used routinely by space weather forecasters, both in the U.S. and internationally. ACE, SOHO (an ESA/NASA collaboration), STEREO, and SDO provide images and in situ measurements that are assimilated into models and cited in alerts and warnings. A number of years ago, the Space Weather laboratory was established at NASA-Goddard, along with the Community Coordinated Modeling Center. Within that organization, a space weather service center has begun issuing alerts for NASA's operational users. NASA's operational user community includes flight operations for human and robotic explorers; atmospheric drag concerns for low-Earth orbit; interplanetary navigation and communication; and the fleet of unmanned aerial vehicles, high altitude aircraft, and launch vehicles. Over the past three years we have identified internal stakeholders within NASA and formed a Working Group to better coordinate their expertise and their needs. In this presentation we will describe this activity and some of the challenges in forming a diverse working group.

Scalable conditional induction variables (CIV) analysis

KAUST Repository

Oancea, Cosmin E.

2015-02-01

Subscripts using induction variables that cannot be expressed as a formula in terms of the enclosing-loop indices appear in the low-level implementation of common programming abstractions such as Alter, or stack operations and pose significant challenges to automatic parallelization. Because the complexity of such induction variables is often due to their conditional evaluation across the iteration space of loops we name them Conditional Induction Variables (CIV). This paper presents a flow-sensitive technique that summarizes both such CIV-based and affine subscripts to program level, using the same representation. Our technique requires no modifications of our dependence tests, which is agnostic to the original shape of the subscripts, and is more powerful than previously reported dependence tests that rely on the pairwise disambiguation of read-write references. We have implemented the CIV analysis in our parallelizing compiler and evaluated its impact on five Fortran benchmarks. We have found that that there are many important loops using CIV subscripts and that our analysis can lead to their scalable parallelization. This in turn has led to the parallelization of the benchmark programs they appear in.

The NASA Polarimetric Radar (NPOL)

Science.gov (United States)

Petersen, Walter A.; Wolff, David B.

2013-01-01

Characteristics of the NASA NPOL S-band dual-polarimetric radar are presented including its operating characteristics, field configuration, scanning capabilities and calibration approaches. Examples of precipitation science data collections conducted using various scan types, and associated products, are presented for different convective system types and previous field campaign deployments. Finally, the NASA NPOL radar location is depicted in its home base configuration within the greater Wallops Flight Facility precipitation research array supporting NASA Global Precipitation Measurement Mission ground validation.

NASA Education Implementation Plan 2015-2017

Science.gov (United States)

National Aeronautics and Space Administration, 2015

2015-01-01

The NASA Education Implementation Plan (NEIP) provides an understanding of the role of NASA in advancing the nation's STEM education and workforce pipeline. The document outlines the roles and responsibilities that NASA Education has in approaching and achieving the agency's and administration's strategic goals in STEM Education. The specific…

Cloud-Based Architectures for Auto-Scalable Web Geoportals towards the Cloudification of the GeoVITe Swiss Academic Geoportal

Directory of Open Access Journals (Sweden)

Ionuț Iosifescu-Enescu

2017-06-01

Full Text Available Cloud computing has redefined the way in which Spatial Data Infrastructures (SDI and Web geoportals are designed, managed, and maintained. The cloudification of a geoportal represents the migration of a full-stack geoportal application to an internet-based private or public cloud. This work introduces two generic and open cloud-based architectures for auto-scalable Web geoportals, illustrated with the use case of the cloudification efforts of the Swiss academic geoportal GeoVITe. The presented cloud-based architectural designs for auto-scalable Web geoportals consider the most important functional and non-functional requirements and are adapted to both public and private clouds. The availability of such generic cloud-based architectures advances the cloudification of academic SDIs and geoportals.

NASA Microgravity Materials Science Conference

Science.gov (United States)

Gillies, D. C. (Compiler); McCauley, D. E. (Compiler)

1999-01-01

The Microgravity Materials Science Conference was held July 14-16, 1998 at the Von Braun Center in Huntsville, AL. It was organized by the Microgravity Materials Science Discipline Working Group, sponsored by the Microgravity Research Division at NASA Headquarters, and hosted by the NASA Marshall Space Flight Center and the Alliance for Microgravity Materials Science and Applications. It was the third NASA conference of this type in the microgravity materials science discipline. The microgravity science program sponsored approximately 125 investigations and 100 principal investigators in FY98, almost all of whom made oral or poster presentations at this conference. The conference's purpose was to inform the materials science community of research opportunities in reduced gravity in preparation for a NASA Research Announcement scheduled for release in late 1998 by the Microgravity Research Division at NASA Headquarters. The conference was aimed at materials science researchers from academia, industry, and government. A tour of the Marshall Space Flight Center microgravity research facilities was held on July 16, 1998. This volume is comprised of the research reports submitted by the principal investigators after the conference.

A Practical and Scalable Tool to Find Overlaps between Sequences

Directory of Open Access Journals (Sweden)

Maan Haj Rachid

2015-01-01

Full Text Available The evolution of the next generation sequencing technology increases the demand for efficient solutions, in terms of space and time, for several bioinformatics problems. This paper presents a practical and easy-to-implement solution for one of these problems, namely, the all-pairs suffix-prefix problem, using a compact prefix tree. The paper demonstrates an efficient construction of this time-efficient and space-economical tree data structure. The paper presents techniques for parallel implementations of the proposed solution. Experimental evaluation indicates superior results in terms of space and time over existing solutions. Results also show that the proposed technique is highly scalable in a parallel execution environment.

Towards Scalability for Federated Identity Systems for Cloud-Based Environments

Directory of Open Access Journals (Sweden)

André Albino Pereira

2015-12-01

Full Text Available As multi-tenant authorization and federated identity management systems for cloud computing matures, the provisioning of services using this paradigm allows maximum efficiency on business that requires access control. However, regarding scalability support, mainly horizontal, some characteristics of those approaches based on central authentication protocols are problematic. The objective of this work is to address these issues by providing an adapted sticky-session mechanism for a Shibboleth architecture using JASIG CAS. This alternative, compared with the recommended distributed memory approach, shown improved efficiency and less overall infrastructure complexity, as well as demanding less 58% of computational resources and improving throughput (requests per second by 11%.

Overview of the Scalable Coherent Interface, IEEE STD 1596 (SCI)

International Nuclear Information System (INIS)

Gustavson, D.B.; James, D.V.; Wiggers, H.A.

1992-10-01

The Scalable Coherent Interface standard defines a new generation of interconnection that spans the full range from supercomputer memory 'bus' to campus-wide network. SCI provides bus-like services and a shared-memory software model while using an underlying, packet protocol on many independent communication links. Initially these links are 1 GByte/s (wires) and 1 GBit/s (fiber), but the protocol scales well to future faster or lower-cost technologies. The interconnect may use switches, meshes, and rings. The SCI distributed-shared-memory model is simple and versatile, enabling for the first time a smooth integration of highly parallel multiprocessors, workstations, personal computers, I/O, networking and data acquisition

Focal plane array with modular pixel array components for scalability

Science.gov (United States)

Kay, Randolph R; Campbell, David V; Shinde, Subhash L; Rienstra, Jeffrey L; Serkland, Darwin K; Holmes, Michael L

2014-12-09

A modular, scalable focal plane array is provided as an array of integrated circuit dice, wherein each die includes a given amount of modular pixel array circuitry. The array of dice effectively multiplies the amount of modular pixel array circuitry to produce a larger pixel array without increasing die size. Desired pixel pitch across the enlarged pixel array is preserved by forming die stacks with each pixel array circuitry die stacked on a separate die that contains the corresponding signal processing circuitry. Techniques for die stack interconnections and die stack placement are implemented to ensure that the desired pixel pitch is preserved across the enlarged pixel array.

Innovation @ NASA

Science.gov (United States)

Roman, Juan A.

2014-01-01

This presentation provides an overview of the activities National Aeronautics and Space Administration (NASA) is doing to encourage innovation across the agency. All information provided is available publicly.

Phonon-based scalable platform for chip-scale quantum computing

Directory of Open Access Journals (Sweden)

Charles M. Reinke

2016-12-01

Full Text Available We present a scalable phonon-based quantum computer on a phononic crystal platform. Practical schemes involve selective placement of a single acceptor atom in the peak of the strain field in a high-Q phononic crystal cavity that enables coupling of the phonon modes to the energy levels of the atom. We show theoretical optimization of the cavity design and coupling waveguide, along with estimated performance figures of the coupled system. A qubit can be created by entangling a phonon at the resonance frequency of the cavity with the atom states. Qubits based on this half-sound, half-matter quasi-particle, called a phoniton, may outcompete other quantum architectures in terms of combined emission rate, coherence lifetime, and fabrication demands.

A Scalable Framework and Prototype for CAS e-Science

Directory of Open Access Journals (Sweden)

Yuanchun Zhou

2007-07-01

Full Text Available Based on the Small-World model of CAS e-Science and the power low of Internet, this paper presents a scalable CAS e-Science Grid framework based on virtual region called Virtual Region Grid Framework (VRGF. VRGF takes virtual region and layer as logic manage-unit. In VRGF, the mode of intra-virtual region is pure P2P, and the model of inter-virtual region is centralized. Therefore, VRGF is decentralized framework with some P2P properties. Further more, VRGF is able to achieve satisfactory performance on resource organizing and locating at a small cost, and is well adapted to the complicated and dynamic features of scientific collaborations. We have implemented a demonstration VRGF based Grid prototype—SDG.

NASA Technologies for Product Identification

Science.gov (United States)

Schramm, Fred, Jr.

2006-01-01

Since 1975 bar codes on products at the retail counter have been accepted as the standard for entering product identity for price determination. Since the beginning of the 21st century, the Data Matrix symbol has become accepted as the bar code format that is marked directly on a part, assembly or product that is durable enough to identify that item for its lifetime. NASA began the studies for direct part marking Data Matrix symbols on parts during the Return to Flight activities after the Challenger Accident. Over the 20 year period that has elapsed since Challenger, a mountain of studies, analyses and focused problem solutions developed by and for NASA have brought about world changing results. NASA Technical Standard 6002 and NASA Handbook 6003 for Direct Part Marking Data Matrix Symbols on Aerospace Parts have formed the basis for most other standards on part marking internationally. NASA and its commercial partners have developed numerous products and methods that addressed the difficulties of collecting part identification in aerospace operations. These products enabled the marking of Data Matrix symbols in virtually every situation and the reading of symbols at great distances, severe angles, under paint and in the dark without a light. Even unmarkable delicate parts now have a process to apply a chemical mixture called NanocodesTM that can be converted to a Data Matrix. The accompanying intellectual property is protected by 10 patents, several of which are licensed. Direct marking Data Matrix on NASA parts virtually eliminates data entry errors and the number of parts that go through their life cycle unmarked, two major threats to sound configuration management and flight safety. NASA is said to only have people and stuff with information connecting them. Data Matrix is one of the most significant improvements since Challenger to the safety and reliability of that connection. This presentation highlights the accomplishments of NASA in its efforts to develop

NASA Airborne Science Program: NASA Stratospheric Platforms

Science.gov (United States)

Curry, Robert E.

2010-01-01

The National Aeronautics and Space Administration conducts a wide variety of remote sensing projects using several unique aircraft platforms. These vehicles have been selected and modified to provide capabilities that are particularly important for geophysical research, in particular, routine access to very high altitudes, long range, long endurance, precise trajectory control, and the payload capacity to operate multiple, diverse instruments concurrently. While the NASA program has been in operation for over 30 years, new aircraft and technological advances that will expand the capabilities for airborne observation are continually being assessed and implemented. This presentation will review the current state of NASA's science platforms, recent improvements and new missions concepts as well as provide a survey of emerging technologies unmanned aerial vehicles for long duration observations (Global Hawk and Predator). Applications of information technology that allow more efficient use of flight time and the ability to rapidly reconfigure systems for different mission objectives are addressed.

NASA Ames Environmental Sustainability Report 2011

Science.gov (United States)

Clarke, Ann H.

2011-01-01

The 2011 Ames Environmental Sustainability Report is the second in a series of reports describing the steps NASA Ames Research Center has taken toward assuring environmental sustainability in NASA Ames programs, projects, and activities. The Report highlights Center contributions toward meeting the Agency-wide goals under the 2011 NASA Strategic Sustainability Performance Program.

Sharing NASA's Scientific Explorations with Communities Across the Country: A Study of Public Libraries Collaborating with NASA STEM Experts

Science.gov (United States)

Dusenbery, P.; LaConte, K.; Holland, A.; Harold, J. B.; Johnson, A.; Randall, C.; Fitzhugh, G.

2017-12-01

NASA research programs are helping humanity understand the origin and evolution of galaxies, stars, and planets, how our Sun varies and impacts the heliosphere, and defining the conditions necessary to support life beyond Earth. As places that offer their services for free, public libraries have become the "public square" by providing a place where members of a community can gather for information, educational programming, and policy discussions. Libraries are also developing new ways to engage their patrons in STEM learning. The Space Science Institute's (SSI) National Center for Interactive Learning (NCIL) was funded by NASA`s Science Mission Directorate (SMD) to develop and implement a project called NASA@ My Library: A National Earth and Space Science Initiative That Connects NASA, Public Libraries and Their Communities. NCIL's STAR Library Network (STAR_Net) is providing important leverage to expand its community of practice that serves both librarians and STEM professionals. Seventy-five libraries were selected through a competitive application process to receive NASA STEM Facilitation Kits, NASA STEM Backpacks for circulation, financial resources, training, and partnership opportunities. Initial survey data from the 75 NASA@ My Library partners showed that, while they are actively providing programming, few STEM programs connected with NASA science and engineering. With the launch of the initiative - including training, resources, and STEM-related event opportunities - all 75 libraries are engaged in offering NASA-focused programs, including with NASA subject matter experts. This talk will highlight the impacts the initiative is having on both public library partners and many others across the country.

A framework for scalable parameter estimation of gene circuit models using structural information

KAUST Repository

Kuwahara, Hiroyuki

2013-06-21

Motivation: Systematic and scalable parameter estimation is a key to construct complex gene regulatory models and to ultimately facilitate an integrative systems biology approach to quantitatively understand the molecular mechanisms underpinning gene regulation. Results: Here, we report a novel framework for efficient and scalable parameter estimation that focuses specifically on modeling of gene circuits. Exploiting the structure commonly found in gene circuit models, this framework decomposes a system of coupled rate equations into individual ones and efficiently integrates them separately to reconstruct the mean time evolution of the gene products. The accuracy of the parameter estimates is refined by iteratively increasing the accuracy of numerical integration using the model structure. As a case study, we applied our framework to four gene circuit models with complex dynamics based on three synthetic datasets and one time series microarray data set. We compared our framework to three state-of-the-art parameter estimation methods and found that our approach consistently generated higher quality parameter solutions efficiently. Although many general-purpose parameter estimation methods have been applied for modeling of gene circuits, our results suggest that the use of more tailored approaches to use domain-specific information may be a key to reverse engineering of complex biological systems. The Author 2013.

A framework for scalable parameter estimation of gene circuit models using structural information

KAUST Repository

Kuwahara, Hiroyuki; Fan, Ming; Wang, Suojin; Gao, Xin

2013-01-01

Motivation: Systematic and scalable parameter estimation is a key to construct complex gene regulatory models and to ultimately facilitate an integrative systems biology approach to quantitatively understand the molecular mechanisms underpinning gene regulation. Results: Here, we report a novel framework for efficient and scalable parameter estimation that focuses specifically on modeling of gene circuits. Exploiting the structure commonly found in gene circuit models, this framework decomposes a system of coupled rate equations into individual ones and efficiently integrates them separately to reconstruct the mean time evolution of the gene products. The accuracy of the parameter estimates is refined by iteratively increasing the accuracy of numerical integration using the model structure. As a case study, we applied our framework to four gene circuit models with complex dynamics based on three synthetic datasets and one time series microarray data set. We compared our framework to three state-of-the-art parameter estimation methods and found that our approach consistently generated higher quality parameter solutions efficiently. Although many general-purpose parameter estimation methods have been applied for modeling of gene circuits, our results suggest that the use of more tailored approaches to use domain-specific information may be a key to reverse engineering of complex biological systems. The Author 2013.

Scalable Directed Assembly of Highly Crystalline 2,7-Dioctyl[1]benzothieno[3,2- b][1]benzothiophene (C8-BTBT) Films.

Science.gov (United States)

Chai, Zhimin; Abbasi, Salman A; Busnaina, Ahmed A

2018-05-30

Assembly of organic semiconductors with ordered crystal structure has been actively pursued for electronics applications such as organic field-effect transistors (OFETs). Among various film deposition methods, solution-based film growth from small molecule semiconductors is preferable because of its low material and energy consumption, low cost, and scalability. Here, we show scalable and controllable directed assembly of highly crystalline 2,7-dioctyl[1]benzothieno[3,2- b][1]benzothiophene (C8-BTBT) films via a dip-coating process. Self-aligned stripe patterns with tunable thickness and morphology over a centimeter scale are obtained by adjusting two governing parameters: the pulling speed of a substrate and the solution concentration. OFETs are fabricated using the C8-BTBT films assembled at various conditions. A field-effect hole mobility up to 3.99 cm 2 V -1 s -1 is obtained. Owing to the highly scalable crystalline film formation, the dip-coating directed assembly process could be a great candidate for manufacturing next-generation electronics. Meanwhile, the film formation mechanism discussed in this paper could provide a general guideline to prepare other organic semiconducting films from small molecule solutions.

NASA directives: Master list and index

Science.gov (United States)

1994-01-01

This Handbook sets forth in two parts the following information for the guidance of users of the NASA Management Directives System. Chapter 1 contains introductory information material on how to use this Handbook. Chapter 2 is a complete master list of Agency-wide management directives, describing each directive by type, number, effective date, expiration date, title, and organization code of the office responsible for the directive. Chapter 3 includes a consolidated numerical list of all delegations of authority and a breakdown of such delegation by the office of Installation to which special authority is assigned. Chapter 4 sets forth a consolidated list of all NASA Handbooks (NHB's) and important footnotes covering the control and ordering of such documents. Chapter 5 is a consolidated list of NASA management directives applicable to the Jet Propulsion Laboratory. Chapter 6 is a consolidated list of NASA management directives published in the code of Federal Regulations. Complementary manuals to the NASA Management Directives System are described in Chapter 7. Part B contains an in-depth alphabetical index to all NASA management directives other than Handbooks.

Visual Communications for Heterogeneous Networks/Visually Optimized Scalable Image Compression. Final Report for September 1, 1995 - February 28, 2002

Energy Technology Data Exchange (ETDEWEB)

Hemami, S. S.

2003-06-03

The authors developed image and video compression algorithms that provide scalability, reconstructibility, and network adaptivity, and developed compression and quantization strategies that are visually optimal at all bit rates. The goal of this research is to enable reliable ''universal access'' to visual communications over the National Information Infrastructure (NII). All users, regardless of their individual network connection bandwidths, qualities-of-service, or terminal capabilities, should have the ability to access still images, video clips, and multimedia information services, and to use interactive visual communications services. To do so requires special capabilities for image and video compression algorithms: scalability, reconstructibility, and network adaptivity. Scalability allows an information service to provide visual information at many rates, without requiring additional compression or storage after the stream has been compressed the first time. Reconstructibility allows reliable visual communications over an imperfect network. Network adaptivity permits real-time modification of compression parameters to adjust to changing network conditions. Furthermore, to optimize the efficiency of the compression algorithms, they should be visually optimal, where each bit expended reduces the visual distortion. Visual optimality is achieved through first extensive experimentation to quantify human sensitivity to supra-threshold compression artifacts and then incorporation of these experimental results into quantization strategies and compression algorithms.

A well-scalable metaheuristic for the fleet size and mix vehicle routing problem with time windows

NARCIS (Netherlands)

Bräysy, Olli; Porkka, Pasi P.; Dullaert, Wout; Repoussis, Panagiotis P.; Tarantilis, Christos D.

This paper presents an efficient and well-scalable metaheuristic for fleet size and mix vehicle routing with time windows. The suggested solution method combines the strengths of well-known threshold accepting and guided local search metaheuristics to guide a set of four local search heuristics. The

NASA OSMA NDE Program Additive Manufacturing Foundational Effort

Science.gov (United States)

Waller, Jess; Walker, James; Burke, Eric; Wells, Douglas; Nichols, Charles

2016-01-01

NASA is providing key leadership in an international effort linking NASA and non-NASA resources to speed adoption of additive manufacturing (AM) to meet NASA's mission goals. Participants include industry, NASA's space partners, other government agencies, standards organizations and academia. Nondestructive Evaluation (NDE) is identified as a universal need for all aspects of additive manufacturing.

New NASA Technologies for Space Exploration

Science.gov (United States)

Calle, Carlos I.

2015-01-01

NASA is developing new technologies to enable planetary exploration. NASA's Space Launch System is an advance vehicle for exploration beyond LEO. Robotic explorers like the Mars Science Laboratory are exploring Mars, making discoveries that will make possible the future human exploration of the planet. In this presentation, we report on technologies being developed at NASA KSC for planetary exploration.

Radiologic image communication and archive service: a secure, scalable, shared approach

Science.gov (United States)

Fellingham, Linda L.; Kohli, Jagdish C.

1995-11-01

The Radiologic Image Communication and Archive (RICA) service is designed to provide a shared archive for medical images to the widest possible audience of customers. Images are acquired from a number of different modalities, each available from many different vendors. Images are acquired digitally from those modalities which support direct digital output and by digitizing films for projection x-ray exams. The RICA Central Archive receives standard DICOM 3.0 messages and data streams from the medical imaging devices at customer institutions over the public telecommunication network. RICA represents a completely scalable resource. The user pays only for what he is using today with the full assurance that as the volume of image data that he wishes to send to the archive increases, the capacity will be there to accept it. To provide this seamless scalability imposes several requirements on the RICA architecture: (1) RICA must support the full array of transport services. (2) The Archive Interface must scale cost-effectively to support local networks that range from the very small (one x-ray digitizer in a medical clinic) to the very large and complex (a large hospital with several CTs, MRs, Nuclear medicine devices, ultrasound machines, CRs, and x-ray digitizers). (3) The Archive Server must scale cost-effectively to support rapidly increasing demands for service providing storage for and access to millions of patients and hundreds of millions of images. The architecture must support the incorporation of improved technology as it becomes available to maintain performance and remain cost-effective as demand rises.

Towards a Scalable Fully-Implicit Fully-coupled Resistive MHD Formulation with Stabilized FE Methods

Energy Technology Data Exchange (ETDEWEB)

Shadid, J N; Pawlowski, R P; Banks, J W; Chacon, L; Lin, P T; Tuminaro, R S

2009-06-03

This paper presents an initial study that is intended to explore the development of a scalable fully-implicit stabilized unstructured finite element (FE) capability for low-Mach-number resistive MHD. The discussion considers the development of the stabilized FE formulation and the underlying fully-coupled preconditioned Newton-Krylov nonlinear iterative solver. To enable robust, scalable and efficient solution of the large-scale sparse linear systems generated by the Newton linearization, fully-coupled algebraic multilevel preconditioners are employed. Verification results demonstrate the expected order-of-acuracy for the stabilized FE discretization of a 2D vector potential form for the steady and transient solution of the resistive MHD system. In addition, this study puts forth a set of challenging prototype problems that include the solution of an MHD Faraday conduction pump, a hydromagnetic Rayleigh-Bernard linear stability calculation, and a magnetic island coalescence problem. Initial results that explore the scaling of the solution methods are presented on up to 4096 processors for problems with up to 64M unknowns on a CrayXT3/4. Additionally, a large-scale proof-of-capability calculation for 1 billion unknowns for the MHD Faraday pump problem on 24,000 cores is presented.

Solution-Processing of Organic Solar Cells: From In Situ Investigation to Scalable Manufacturing

KAUST Repository

Abdelsamie, Maged

2016-12-05

Photovoltaics provide a feasible route to fulfilling the substantial increase in demand for energy worldwide. Solution processable organic photovoltaics (OPVs) have attracted attention in the last decade because of the promise of low-cost manufacturing of sufficiently efficient devices at high throughput on large-area rigid or flexible substrates with potentially low energy and carbon footprints. In OPVs, the photoactive layer is made of a bulk heterojunction (BHJ) layer and is typically composed of a blend of an electron-donating (D) and an electron-accepting (A) materials which phase separate at the nanoscale and form a heterojunction at the D-A interface that plays a crucial role in the generation of charges. Despite the tremendous progress that has been made in increasing the efficiency of organic photovoltaics over the last few years, with power conversion efficiency increasing from 8% to 13% over the duration of this PhD dissertation, there have been numerous debates on the mechanisms of formation of the crucial BHJ layer and few clues about how to successfully transfer these lessons to scalable processes. This stems in large part from a lack of understanding of how BHJ layers form from solution. This lack of understanding makes it challenging to design BHJs and to control their formation in laboratory-based processes, such as spin-coating, let alone their successful transfer to scalable processes required for the manufacturing of organic solar cells. Consequently, the OPV community has in recent years sought out to better understand the key characteristics of state of the art lab-based organic solar cells and made efforts to shed light on how the BHJ forms in laboratory-based processes as well as in scalable processes. We take the view that understanding the formation of the solution-processed bulk heterojunction (BHJ) photoactive layer, where crucial photovoltaic processes take place, is the one of the most crucial steps to developing strategies towards the

NASA SMD STEM Activation: Enabling NASA Science Experts and Content into the Learning Environment

Science.gov (United States)

Hasan, Hashima; Erickson, Kristen

2018-01-01

The NASA Science Mission Directorate (SMD) restructured its efforts to enhance learning in science, technology, engineering, and mathematics (STEM) content areas through a cooperative agreement notice issued in 2015. This effort resulted in the competitive selection of 27 organizations to implement a strategic approach that leverages SMD’s unique assets. Three of these are exclusively directed towards Astrophysics. These unique assets include SMD’s science and engineering content and Science Discipline Subject Matter Experts. Awardees began their work during 2016 and span all areas of Earth and space science and the audiences NASA SMD intends to reach. The goal of the restructured STEM Activation program is to further enable NASA science experts and content into the learning environment more effectively and efficiently with learners of all ages. The objectives are to enable STEM education, improve US scientific literacy, advance national educational goals, and leverage efforts through partnerships. This presentation will provide an overview of the NASA SMD STEM Activation landscape and its commitment to meeting user needs.

Scalable Fabrication of Integrated Nanophotonic Circuits on Arrays of Thin Single Crystal Diamond Membrane Windows.

Science.gov (United States)

Piracha, Afaq H; Rath, Patrik; Ganesan, Kumaravelu; Kühn, Stefan; Pernice, Wolfram H P; Prawer, Steven

2016-05-11

Diamond has emerged as a promising platform for nanophotonic, optical, and quantum technologies. High-quality, single crystalline substrates of acceptable size are a prerequisite to meet the demanding requirements on low-level impurities and low absorption loss when targeting large photonic circuits. Here, we describe a scalable fabrication method for single crystal diamond membrane windows that achieves three major goals with one fabrication method: providing high quality diamond, as confirmed by Raman spectroscopy; achieving homogeneously thin membranes, enabled by ion implantation; and providing compatibility with established planar fabrication via lithography and vertical etching. On such suspended diamond membranes we demonstrate a suite of photonic components as building blocks for nanophotonic circuits. Monolithic grating couplers are used to efficiently couple light between photonic circuits and optical fibers. In waveguide coupled optical ring resonators, we find loaded quality factors up to 66 000 at a wavelength of 1560 nm, corresponding to propagation loss below 7.2 dB/cm. Our approach holds promise for the scalable implementation of future diamond quantum photonic technologies and all-diamond photonic metrology tools.

Scalable Task Assignment for Heterogeneous Multi-Robot Teams

Directory of Open Access Journals (Sweden)

Paula García

2013-02-01

Full Text Available This work deals with the development of a dynamic task assignment strategy for heterogeneous multi-robot teams in typical real world scenarios. The strategy must be efficiently scalable to support problems of increasing complexity with minimum designer intervention. To this end, we have selected a very simple auction-based strategy, which has been implemented and analysed in a multi-robot cleaning problem that requires strong coordination and dynamic complex subtask organization. We will show that the selection of a simple auction strategy provides a linear computational cost increase with the number of robots that make up the team and allows the solving of highly complex assignment problems in dynamic conditions by means of a hierarchical sub-auction policy. To coordinate and control the team, a layered behaviour-based architecture has been applied that allows the reusing of the auction-based strategy to achieve different coordination levels.

Scalable Domain Decomposition Preconditioners for Heterogeneous Elliptic Problems

Directory of Open Access Journals (Sweden)

Pierre Jolivet

2014-01-01

Full Text Available Domain decomposition methods are, alongside multigrid methods, one of the dominant paradigms in contemporary large-scale partial differential equation simulation. In this paper, a lightweight implementation of a theoretically and numerically scalable preconditioner is presented in the context of overlapping methods. The performance of this work is assessed by numerical simulations executed on thousands of cores, for solving various highly heterogeneous elliptic problems in both 2D and 3D with billions of degrees of freedom. Such problems arise in computational science and engineering, in solid and fluid mechanics. While focusing on overlapping domain decomposition methods might seem too restrictive, it will be shown how this work can be applied to a variety of other methods, such as non-overlapping methods and abstract deflation based preconditioners. It is also presented how multilevel preconditioners can be used to avoid communication during an iterative process such as a Krylov method.

Scalable Lunar Surface Networks and Adaptive Orbit Access

Science.gov (United States)

Wang, Xudong

2015-01-01

Teranovi Technologies, Inc., has developed innovative network architecture, protocols, and algorithms for both lunar surface and orbit access networks. A key component of the overall architecture is a medium access control (MAC) protocol that includes a novel mechanism of overlaying time division multiple access (TDMA) and carrier sense multiple access with collision avoidance (CSMA/CA), ensuring scalable throughput and quality of service. The new MAC protocol is compatible with legacy Institute of Electrical and Electronics Engineers (IEEE) 802.11 networks. Advanced features include efficiency power management, adaptive channel width adjustment, and error control capability. A hybrid routing protocol combines the advantages of ad hoc on-demand distance vector (AODV) routing and disruption/delay-tolerant network (DTN) routing. Performance is significantly better than AODV or DTN and will be particularly effective for wireless networks with intermittent links, such as lunar and planetary surface networks and orbit access networks.

Development of a modular and scalable sensor system for the gathering of position and orientation of moved objects

International Nuclear Information System (INIS)

Klingbeil, L.

2006-02-01

A modular and scalable sensor system for the estimation of position and orientation of moving objects has been developed and characterized. A sensor unit, which is mounted to the moving object, consists of acceleration -, angular rate - and magnetic field sensors for every spatial axis. Customized Kalman filter algorithms provide a robust and low latency reconstruction of the sensor's orientation. Additionally an ultrasound transducer network is used to measure the distance of a sensor unit with respect to several reference points in the room. This allows reconstruction of the absolute position using trilateration methods. The system is scalable with respect to the number of sensor units and the covered tracking volume. It is suitable for various applications for example the analysis of body movements or head tracking in augmented or virtual reality environments. (orig.)

Scalability analysis of large-scale LoRaWAN networks in ns-3

OpenAIRE

Abeele, Floris Van den; Haxhibeqiri, Jetmir; Moerman, Ingrid; Hoebeke, Jeroen

2017-01-01

As LoRaWAN networks are actively being deployed in the field, it is important to comprehend the limitations of this Low Power Wide Area Network technology. Previous work has raised questions in terms of the scalability and capacity of LoRaWAN networks as the number of end devices grows to hundreds or thousands per gateway. Some works have modeled LoRaWAN networks as pure ALOHA networks, which fails to capture important characteristics such as the capture effect and the effects of interference...

Investigation of the blockchain systems’ scalability features using the agent based modelling

OpenAIRE

Šulnius, Aleksas

2017-01-01

Investigation of the BlockChain Systems’ Scalability Features using the Agent Based Modelling. BlockChain currently is in the spotlight of all the FinTech industry. This technology is being called revolutionary, ground breaking, disruptive and even the WEB 3.0. On the other hand it is widely agreed that the BlockChain is in its early stages of development. In its current state BlockChain is in similar position that the Internet was in the early nineties. In order for this technology to gain m...

A Scalable Architecture for VoIP Conferencing

Directory of Open Access Journals (Sweden)

R Venkatesha Prasad

2003-10-01

Full Text Available Real-Time services are traditionally supported on circuit switched network. However, there is a need to port these services on packet switched network. Architecture for audio conferencing application over the Internet in the light of ITU-T H.323 recommendations is considered. In a conference, considering packets only from a set of selected clients can reduce speech quality degradation because mixing packets from all clients can lead to lack of speech clarity. A distributed algorithm and architecture for selecting clients for mixing is suggested here based on a new quantifier of the voice activity called "Loudness Number" (LN. The proposed system distributes the computation load and reduces the load on client terminals. The highlights of this architecture are scalability, bandwidth saving and speech quality enhancement. Client selection for playing out tries to mimic a physical conference where the most vocal participants attract more attention. The contributions of the paper are expected to aid H.323 recommendations implementations for Multipoint Processors (MP. A working prototype based on the proposed architecture is already functional.

Scalable Multi-Platform Distribution of Spatial 3d Contents

Science.gov (United States)

Klimke, J.; Hagedorn, B.; Döllner, J.

2013-09-01

Virtual 3D city models provide powerful user interfaces for communication of 2D and 3D geoinformation. Providing high quality visualization of massive 3D geoinformation in a scalable, fast, and cost efficient manner is still a challenging task. Especially for mobile and web-based system environments, software and hardware configurations of target systems differ significantly. This makes it hard to provide fast, visually appealing renderings of 3D data throughout a variety of platforms and devices. Current mobile or web-based solutions for 3D visualization usually require raw 3D scene data such as triangle meshes together with textures delivered from server to client, what makes them strongly limited in terms of size and complexity of the models they can handle. In this paper, we introduce a new approach for provisioning of massive, virtual 3D city models on different platforms namely web browsers, smartphones or tablets, by means of an interactive map assembled from artificial oblique image tiles. The key concept is to synthesize such images of a virtual 3D city model by a 3D rendering service in a preprocessing step. This service encapsulates model handling and 3D rendering techniques for high quality visualization of massive 3D models. By generating image tiles using this service, the 3D rendering process is shifted from the client side, which provides major advantages: (a) The complexity of the 3D city model data is decoupled from data transfer complexity (b) the implementation of client applications is simplified significantly as 3D rendering is encapsulated on server side (c) 3D city models can be easily deployed for and used by a large number of concurrent users, leading to a high degree of scalability of the overall approach. All core 3D rendering techniques are performed on a dedicated 3D rendering server, and thin-client applications can be compactly implemented for various devices and platforms.

A Cross-Platform Infrastructure for Scalable Runtime Application Performance Analysis

Energy Technology Data Exchange (ETDEWEB)

Jack Dongarra; Shirley Moore; Bart Miller, Jeffrey Hollingsworth; Tracy Rafferty

2005-03-15

The purpose of this project was to build an extensible cross-platform infrastructure to facilitate the development of accurate and portable performance analysis tools for current and future high performance computing (HPC) architectures. Major accomplishments include tools and techniques for multidimensional performance analysis, as well as improved support for dynamic performance monitoring of multithreaded and multiprocess applications. Previous performance tool development has been limited by the burden of having to re-write a platform-dependent low-level substrate for each architecture/operating system pair in order to obtain the necessary performance data from the system. Manual interpretation of performance data is not scalable for large-scale long-running applications. The infrastructure developed by this project provides a foundation for building portable and scalable performance analysis tools, with the end goal being to provide application developers with the information they need to analyze, understand, and tune the performance of terascale applications on HPC architectures. The backend portion of the infrastructure provides runtime instrumentation capability and access to hardware performance counters, with thread-safety for shared memory environments and a communication substrate to support instrumentation of multiprocess and distributed programs. Front end interfaces provides tool developers with a well-defined, platform-independent set of calls for requesting performance data. End-user tools have been developed that demonstrate runtime data collection, on-line and off-line analysis of performance data, and multidimensional performance analysis. The infrastructure is based on two underlying performance instrumentation technologies. These technologies are the PAPI cross-platform library interface to hardware performance counters and the cross-platform Dyninst library interface for runtime modification of executable images. The Paradyn and KOJAK

14 CFR 1221.103 - Establishment of the NASA Insignia.

Science.gov (United States)

2010-01-01

..., NASA Program Identifiers, NASA Flags, and the Agency's Unified Visual Communications System § 1221.103... approved by the Commission of Fine Arts and the NASA Administrator. It symbolizes NASA's role in... visual communications formerly reserved for the NASA Logotype. The NASA Insignia shall be used as set...

Mechanical characterization of scalable cellulose nano-fiber based composites made using liquid composite molding process

Science.gov (United States)

Bamdad Barari; Thomas K. Ellingham; Issam I. Ghamhia; Krishna M. Pillai; Rani El-Hajjar; Lih-Sheng Turng; Ronald Sabo

2016-01-01

Plant derived cellulose nano-fibers (CNF) are a material with remarkable mechanical properties compared to other natural fibers. However, efforts to produce nano-composites on a large scale using CNF have yet to be investigated. In this study, scalable CNF nano-composites were made from isotropically porous CNF preforms using a freeze drying process. An improvised...

The ELPA library: scalable parallel eigenvalue solutions for electronic structure theory and computational science.

Science.gov (United States)

Marek, A; Blum, V; Johanni, R; Havu, V; Lang, B; Auckenthaler, T; Heinecke, A; Bungartz, H-J; Lederer, H

2014-05-28

Obtaining the eigenvalues and eigenvectors of large matrices is a key problem in electronic structure theory and many other areas of computational science. The computational effort formally scales as O(N(3)) with the size of the investigated problem, N (e.g. the electron count in electronic structure theory), and thus often defines the system size limit that practical calculations cannot overcome. In many cases, more than just a small fraction of the possible eigenvalue/eigenvector pairs is needed, so that iterative solution strategies that focus only on a few eigenvalues become ineffective. Likewise, it is not always desirable or practical to circumvent the eigenvalue solution entirely. We here review some current developments regarding dense eigenvalue solvers and then focus on the Eigenvalue soLvers for Petascale Applications (ELPA) library, which facilitates the efficient algebraic solution of symmetric and Hermitian eigenvalue problems for dense matrices that have real-valued and complex-valued matrix entries, respectively, on parallel computer platforms. ELPA addresses standard as well as generalized eigenvalue problems, relying on the well documented matrix layout of the Scalable Linear Algebra PACKage (ScaLAPACK) library but replacing all actual parallel solution steps with subroutines of its own. For these steps, ELPA significantly outperforms the corresponding ScaLAPACK routines and proprietary libraries that implement the ScaLAPACK interface (e.g. Intel's MKL). The most time-critical step is the reduction of the matrix to tridiagonal form and the corresponding backtransformation of the eigenvectors. ELPA offers both a one-step tridiagonalization (successive Householder transformations) and a two-step transformation that is more efficient especially towards larger matrices and larger numbers of CPU cores. ELPA is based on the MPI standard, with an early hybrid MPI-OpenMPI implementation available as well. Scalability beyond 10,000 CPU cores for problem

Industrial and Systems Engineering Applications in NASA

Science.gov (United States)

Shivers, Charles H.

2006-01-01

A viewgraph presentation on the many applications of Industrial and Systems Engineering used for safe NASA missions is shown. The topics include: 1) NASA Information; 2) Industrial Engineering; 3) Systems Engineering; and 4) Major NASA Programs.