How much is too much assessment? Insight into assessment-driven student learning gains in large-scale undergraduate microbiology courses.

Science.gov (United States)

Wang, Jack T H; Schembri, Mark A; Hall, Roy A

2013-01-01

Designing and implementing assessment tasks in large-scale undergraduate science courses is a labor-intensive process subject to increasing scrutiny from students and quality assurance authorities alike. Recent pedagogical research has provided conceptual frameworks for teaching introductory undergraduate microbiology, but has yet to define best-practice assessment guidelines. This study assessed the applicability of Biggs' theory of constructive alignment in designing consistent learning objectives, activities, and assessment items that aligned with the American Society for Microbiology's concept-based microbiology curriculum in MICR2000, an introductory microbiology course offered at the University of Queensland, Australia. By improving the internal consistency in assessment criteria and increasing the number of assessment items explicitly aligned to the course learning objectives, the teaching team was able to efficiently provide adequate feedback on numerous assessment tasks throughout the semester, which contributed to improved student performance and learning gains. When comparing the constructively aligned 2011 offering of MICR2000 with its 2010 counterpart, students obtained higher marks in both coursework assignments and examinations as the semester progressed. Students also valued the additional feedback provided, as student rankings for course feedback provision increased in 2011 and assessment and feedback was identified as a key strength of MICR2000. By designing MICR2000 using constructive alignment and iterative assessment tasks that followed a common set of learning outcomes, the teaching team was able to effectively deliver detailed and timely feedback in a large introductory microbiology course. This study serves as a case study for how constructive alignment can be integrated into modern teaching practices for large-scale courses.

Large scale and performance tests of the ATLAS online software

International Nuclear Information System (INIS)

Alexandrov; Kotov, V.; Mineev, M.; Roumiantsev, V.; Wolters, H.; Amorim, A.; Pedro, L.; Ribeiro, A.; Badescu, E.; Caprini, M.; Burckhart-Chromek, D.; Dobson, M.; Jones, R.; Kazarov, A.; Kolos, S.; Liko, D.; Lucio, L.; Mapelli, L.; Nassiakou, M.; Schweiger, D.; Soloviev, I.; Hart, R.; Ryabov, Y.; Moneta, L.

2001-01-01

One of the sub-systems of the Trigger/DAQ system of the future ATLAS experiment is the Online Software system. It encompasses the functionality needed to configure, control and monitor the DAQ. Its architecture is based on a component structure described in the ATLAS Trigger/DAQ technical proposal. Regular integration tests ensure its smooth operation in test beam setups during its evolutionary development towards the final ATLAS online system. Feedback is received and returned into the development process. Studies of the system behavior have been performed on a set of up to 111 PCs on a configuration which is getting closer to the final size. Large scale and performance test of the integrated system were performed on this setup with emphasis on investigating the aspects of the inter-dependence of the components and the performance of the communication software. Of particular interest were the run control state transitions in various configurations of the run control hierarchy. For the purpose of the tests, the software from other Trigger/DAQ sub-systems has been emulated. The author presents a brief overview of the online system structure, its components and the large scale integration tests and their results

Analysis of environmental impact assessment for large-scale X-ray medical equipments

International Nuclear Information System (INIS)

Fu Jin; Pei Chengkai

2011-01-01

Based on an Environmental Impact Assessment (EIA) project, this paper elaborates the basic analysis essentials of EIA for the sales project of large-scale X-ray medical equipment, and provides the analysis procedure of environmental impact and dose estimation method under normal and accident conditions. The key points of EIA for the sales project of large-scale X-ray medical equipment include the determination of pollution factor and management limit value according to the project's actual situation, the utilization of various methods of assessment and prediction such as analogy, actual measurement and calculation to analyze, monitor, calculate and predict the pollution during normal and accident condition. (authors)

A conceptual analysis of standard setting in large-scale assessments

NARCIS (Netherlands)

van der Linden, Willem J.

1994-01-01

Elements of arbitrariness in the standard setting process are explored, and an alternative to the use of cut scores is presented. The first part of the paper analyzes the use of cut scores in large-scale assessments, discussing three different functions: (1) cut scores define the qualifications used

Analytical Assessment of the Relationship between 100MWp Large-scale Grid-connected Photovoltaic Plant Performance and Meteorological Parameters

Science.gov (United States)

Sheng, Jie; Zhu, Qiaoming; Cao, Shijie; You, Yang

2017-05-01

This paper helps in study of the relationship between the photovoltaic power generation of large scale “fishing and PV complementary” grid-tied photovoltaic system and meteorological parameters, with multi-time scale power data from the photovoltaic power station and meteorological data over the same period of a whole year. The result indicates that, the PV power generation has the most significant correlation with global solar irradiation, followed by diurnal temperature range, sunshine hours, daily maximum temperature and daily average temperature. In different months, the maximum monthly average power generation appears in August, which related to the more global solar irradiation and longer sunshine hours in this month. However, the maximum daily average power generation appears in October, this is due to the drop in temperature brings about the improvement of the efficiency of PV panels. Through the contrast of monthly average performance ratio (PR) and monthly average temperature, it is shown that, the larger values of monthly average PR appears in April and October, while it is smaller in summer with higher temperature. The results concluded that temperature has a great influence on the performance ratio of large scale grid-tied PV power system, and it is important to adopt effective measures to decrease the temperature of PV plant properly.

Assessment of renewable energy resources potential for large scale and standalone applications in Ethiopia

NARCIS (Netherlands)

Tucho, Gudina Terefe; Weesie, Peter D.M.; Nonhebel, Sanderine

2014-01-01

This study aims to determine the contribution of renewable energy to large scale and standalone application in Ethiopia. The assessment starts by determining the present energy system and the available potentials. Subsequently, the contribution of the available potentials for large scale and

Overview of large scale experiments performed within the LBB project in the Czech Republic

Energy Technology Data Exchange (ETDEWEB)

Kadecka, P.; Lauerova, D. [Nuclear Research Institute, Rez (Czechoslovakia)

1997-04-01

During several recent years NRI Rez has been performing the LBB analyses of safety significant primary circuit pipings of NPPs in Czech and Slovak Republics. The analyses covered the NPPs with reactors WWER 440 Type 230 and 213 and WWER 1000 Type 320. Within the relevant LBB projects undertaken with the aim to prove the fulfilling of the requirements of LBB, a series of large scale experiments were performed. The goal of these experiments was to verify the properties of the components selected, and to prove the quality and/or conservatism of assessments used in the LBB-analyses. In this poster, a brief overview of experiments performed in Czech Republic under guidance of NRI Rez is presented.

Twelve tips for assessing surgical performance and use of technical assessment scales

DEFF Research Database (Denmark)

Strandbygaard, Jeanett; Scheele, Fedde; Sørensen, Jette Led

2017-01-01

Using validated assessment scales for technical competence can help structure and standardize assessment and feedback for both the trainee and the supervisor and thereby avoid bias and drive learning. Correct assessment of operative skills can establish learning curves and allow adequate monitoring....... However, the assessment of surgical performance is not an easy task, since it includes many proxy parameters, which are hard to measure. Although numerous technical assessment scales exist, both within laparoscopic and open surgery, the validity evidence is often sparse, and this can raise doubts about...... reliability and educational outcome. Furthermore, the implementation of technical assessment scales varies due to several obstacles and doubts about accurate use. In this 12-tips article, we aim to give the readers a critical and useful appraisal of some of the common questions and misunderstandings regarding...

Large-scale multimedia modeling applications

International Nuclear Information System (INIS)

Droppo, J.G. Jr.; Buck, J.W.; Whelan, G.; Strenge, D.L.; Castleton, K.J.; Gelston, G.M.

1995-08-01

Over the past decade, the US Department of Energy (DOE) and other agencies have faced increasing scrutiny for a wide range of environmental issues related to past and current practices. A number of large-scale applications have been undertaken that required analysis of large numbers of potential environmental issues over a wide range of environmental conditions and contaminants. Several of these applications, referred to here as large-scale applications, have addressed long-term public health risks using a holistic approach for assessing impacts from potential waterborne and airborne transport pathways. Multimedia models such as the Multimedia Environmental Pollutant Assessment System (MEPAS) were designed for use in such applications. MEPAS integrates radioactive and hazardous contaminants impact computations for major exposure routes via air, surface water, ground water, and overland flow transport. A number of large-scale applications of MEPAS have been conducted to assess various endpoints for environmental and human health impacts. These applications are described in terms of lessons learned in the development of an effective approach for large-scale applications

Using Procedure Based on Item Response Theory to Evaluate Classification Consistency Indices in the Practice of Large-Scale Assessment

Directory of Open Access Journals (Sweden)

Shanshan Zhang

2017-09-01

Full Text Available In spite of the growing interest in the methods of evaluating the classification consistency (CC indices, only few researches are available in the field of applying these methods in the practice of large-scale educational assessment. In addition, only few studies considered the influence of practical factors, for example, the examinee ability distribution, the cut score location and the score scale, on the performance of CC indices. Using the newly developed Lee's procedure based on the item response theory (IRT, the main purpose of this study is to investigate the performance of CC indices when practical factors are taken into consideration. A simulation study and an empirical study were conducted under comprehensive conditions. Results suggested that with negatively skewed distribution, the CC indices were larger than with other distributions. Interactions occurred among ability distribution, cut score location, and score scale. Consequently, Lee's IRT procedure is reliable to be used in the field of large-scale educational assessment, and when reporting the indices, it should be treated with caution as testing conditions may vary a lot.

Assessing the performance of multi-purpose channel management measures at increasing scales

Science.gov (United States)

Wilkinson, Mark; Addy, Steve

2016-04-01

In addition to hydroclimatic drivers, sediment deposition from high energy river systems can reduce channel conveyance capacity and lead to significant increases in flood risk. There is an increasing recognition that we need to work with the interplay of natural hydrological and morphological processes in order to attenuate flood flows and manage sediment (both coarse and fine). This typically includes both catchment (e.g. woodland planting, wetlands) and river (e.g. wood placement, floodplain reconnection) restoration approaches. The aim of this work was to assess at which scales channel management measures (notably wood placement and flood embankment removal) are most appropriate for flood and sediment management in high energy upland river systems. We present research findings from two densely instrumented research sites in Scotland which regularly experience flood events and have associated coarse sediment problems. We assessed the performance of a range of novel trial measures for three different scales: wooded flow restrictors and gully tree planting at the small scale (transport to optimise performance. At the large scale, well designed flood embankment lowering can improve connectivity to the floodplain during low to medium return period events. However, ancillary works to stabilise the bank failed thus emphasising the importance of letting natural processes readjust channel morphology and hydrological connections to the floodplain. Although these trial measures demonstrated limited effects, this may be in part owing to restrictions in the range of hydroclimatological conditions during the study period and further work is needed to assess the performance under more extreme conditions. This work will contribute to refining guidance for managing channel coarse sediment problems in the future which in turn could help mitigate flooding using natural approaches.

Do large-scale assessments measure students' ability to integrate scientific knowledge?

Science.gov (United States)

Lee, Hee-Sun

2010-03-01

Large-scale assessments are used as means to diagnose the current status of student achievement in science and compare students across schools, states, and countries. For efficiency, multiple-choice items and dichotomously-scored open-ended items are pervasively used in large-scale assessments such as Trends in International Math and Science Study (TIMSS). This study investigated how well these items measure secondary school students' ability to integrate scientific knowledge. This study collected responses of 8400 students to 116 multiple-choice and 84 open-ended items and applied an Item Response Theory analysis based on the Rasch Partial Credit Model. Results indicate that most multiple-choice items and dichotomously-scored open-ended items can be used to determine whether students have normative ideas about science topics, but cannot measure whether students integrate multiple pieces of relevant science ideas. Only when the scoring rubric is redesigned to capture subtle nuances of student open-ended responses, open-ended items become a valid and reliable tool to assess students' knowledge integration ability.

The use of test scores from large-scale assessment surveys: psychometric and statistical considerations

Directory of Open Access Journals (Sweden)

Henry Braun

2017-11-01

Full Text Available Abstract Background Economists are making increasing use of measures of student achievement obtained through large-scale survey assessments such as NAEP, TIMSS, and PISA. The construction of these measures, employing plausible value (PV methodology, is quite different from that of the more familiar test scores associated with assessments such as the SAT or ACT. These differences have important implications both for utilization and interpretation. Although much has been written about PVs, it appears that there are still misconceptions about whether and how to employ them in secondary analyses. Methods We address a range of technical issues, including those raised in a recent article that was written to inform economists using these databases. First, an extensive review of the relevant literature was conducted, with particular attention to key publications that describe the derivation and psychometric characteristics of such achievement measures. Second, a simulation study was carried out to compare the statistical properties of estimates based on the use of PVs with those based on other, commonly used methods. Results It is shown, through both theoretical analysis and simulation, that under fairly general conditions appropriate use of PV yields approximately unbiased estimates of model parameters in regression analyses of large scale survey data. The superiority of the PV methodology is particularly evident when measures of student achievement are employed as explanatory variables. Conclusions The PV methodology used to report student test performance in large scale surveys remains the state-of-the-art for secondary analyses of these databases.

Performance modeling of hybrid MPI/OpenMP scientific applications on large-scale multicore supercomputers

KAUST Repository

Wu, Xingfu; Taylor, Valerie

2013-01-01

In this paper, we present a performance modeling framework based on memory bandwidth contention time and a parameterized communication model to predict the performance of OpenMP, MPI and hybrid applications with weak scaling on three large-scale multicore supercomputers: IBM POWER4, POWER5+ and BlueGene/P, and analyze the performance of these MPI, OpenMP and hybrid applications. We use STREAM memory benchmarks and Intel's MPI benchmarks to provide initial performance analysis and model validation of MPI and OpenMP applications on these multicore supercomputers because the measured sustained memory bandwidth can provide insight into the memory bandwidth that a system should sustain on scientific applications with the same amount of workload per core. In addition to using these benchmarks, we also use a weak-scaling hybrid MPI/OpenMP large-scale scientific application: Gyrokinetic Toroidal Code (GTC) in magnetic fusion to validate our performance model of the hybrid application on these multicore supercomputers. The validation results for our performance modeling method show less than 7.77% error rate in predicting the performance of hybrid MPI/OpenMP GTC on up to 512 cores on these multicore supercomputers. © 2013 Elsevier Inc.

Performance modeling of hybrid MPI/OpenMP scientific applications on large-scale multicore supercomputers

KAUST Repository

Wu, Xingfu

2013-12-01

In this paper, we present a performance modeling framework based on memory bandwidth contention time and a parameterized communication model to predict the performance of OpenMP, MPI and hybrid applications with weak scaling on three large-scale multicore supercomputers: IBM POWER4, POWER5+ and BlueGene/P, and analyze the performance of these MPI, OpenMP and hybrid applications. We use STREAM memory benchmarks and Intel\\'s MPI benchmarks to provide initial performance analysis and model validation of MPI and OpenMP applications on these multicore supercomputers because the measured sustained memory bandwidth can provide insight into the memory bandwidth that a system should sustain on scientific applications with the same amount of workload per core. In addition to using these benchmarks, we also use a weak-scaling hybrid MPI/OpenMP large-scale scientific application: Gyrokinetic Toroidal Code (GTC) in magnetic fusion to validate our performance model of the hybrid application on these multicore supercomputers. The validation results for our performance modeling method show less than 7.77% error rate in predicting the performance of hybrid MPI/OpenMP GTC on up to 512 cores on these multicore supercomputers. © 2013 Elsevier Inc.

Improving Large-scale Storage System Performance via Topology-aware and Balanced Data Placement

Energy Technology Data Exchange (ETDEWEB)

Wang, Feiyi [ORNL; Oral, H Sarp [ORNL; Vazhkudai, Sudharshan S [ORNL

2014-01-01

With the advent of big data, the I/O subsystems of large-scale compute clusters are becoming a center of focus, with more applications putting greater demands on end-to-end I/O performance. These subsystems are often complex in design. They comprise of multiple hardware and software layers to cope with the increasing capacity, capability and scalability requirements of data intensive applications. The sharing nature of storage resources and the intrinsic interactions across these layers make it to realize user-level, end-to-end performance gains a great challenge. We propose a topology-aware resource load balancing strategy to improve per-application I/O performance. We demonstrate the effectiveness of our algorithm on an extreme-scale compute cluster, Titan, at the Oak Ridge Leadership Computing Facility (OLCF). Our experiments with both synthetic benchmarks and a real-world application show that, even under congestion, our proposed algorithm can improve large-scale application I/O performance significantly, resulting in both the reduction of application run times and higher resolution simulation runs.

Explore the Usefulness of Person-Fit Analysis on Large-Scale Assessment

Science.gov (United States)

Cui, Ying; Mousavi, Amin

2015-01-01

The current study applied the person-fit statistic, l[subscript z], to data from a Canadian provincial achievement test to explore the usefulness of conducting person-fit analysis on large-scale assessments. Item parameter estimates were compared before and after the misfitting student responses, as identified by l[subscript z], were removed. The…

High-Performance Monitoring Architecture for Large-Scale Distributed Systems Using Event Filtering

Science.gov (United States)

Maly, K.

1998-01-01

Monitoring is an essential process to observe and improve the reliability and the performance of large-scale distributed (LSD) systems. In an LSD environment, a large number of events is generated by the system components during its execution or interaction with external objects (e.g. users or processes). Monitoring such events is necessary for observing the run-time behavior of LSD systems and providing status information required for debugging, tuning and managing such applications. However, correlated events are generated concurrently and could be distributed in various locations in the applications environment which complicates the management decisions process and thereby makes monitoring LSD systems an intricate task. We propose a scalable high-performance monitoring architecture for LSD systems to detect and classify interesting local and global events and disseminate the monitoring information to the corresponding end- points management applications such as debugging and reactive control tools to improve the application performance and reliability. A large volume of events may be generated due to the extensive demands of the monitoring applications and the high interaction of LSD systems. The monitoring architecture employs a high-performance event filtering mechanism to efficiently process the large volume of event traffic generated by LSD systems and minimize the intrusiveness of the monitoring process by reducing the event traffic flow in the system and distributing the monitoring computation. Our architecture also supports dynamic and flexible reconfiguration of the monitoring mechanism via its Instrumentation and subscription components. As a case study, we show how our monitoring architecture can be utilized to improve the reliability and the performance of the Interactive Remote Instruction (IRI) system which is a large-scale distributed system for collaborative distance learning. The filtering mechanism represents an Intrinsic component integrated

Nuclear-pumped lasers for large-scale applications

International Nuclear Information System (INIS)

Anderson, R.E.; Leonard, E.M.; Shea, R.F.; Berggren, R.R.

1989-05-01

Efficient initiation of large-volume chemical lasers may be achieved by neutron induced reactions which produce charged particles in the final state. When a burst mode nuclear reactor is used as the neutron source, both a sufficiently intense neutron flux and a sufficiently short initiation pulse may be possible. Proof-of-principle experiments are planned to demonstrate lasing in a direct nuclear-pumped large-volume system; to study the effects of various neutron absorbing materials on laser performance; to study the effects of long initiation pulse lengths; to demonstrate the performance of large-scale optics and the beam quality that may be obtained; and to assess the performance of alternative designs of burst systems that increase the neutron output and burst repetition rate. 21 refs., 8 figs., 5 tabs

Secondary Analysis of Large-Scale Assessment Data: An Alternative to Variable-Centred Analysis

Science.gov (United States)

Chow, Kui Foon; Kennedy, Kerry John

2014-01-01

International large-scale assessments are now part of the educational landscape in many countries and often feed into major policy decisions. Yet, such assessments also provide data sets for secondary analysis that can address key issues of concern to educators and policymakers alike. Traditionally, such secondary analyses have been based on a…

Performance evaluation of the DCMD desalination process under bench scale and large scale module operating conditions

KAUST Repository

Francis, Lijo

2014-04-01

The flux performance of different hydrophobic microporous flat sheet commercial membranes made of poly tetrafluoroethylene (PTFE) and poly propylene (PP) was tested for Red Sea water desalination using the direct contact membrane distillation (DCMD) process, under bench scale (high δT) and large scale module (low δT) operating conditions. Membranes were characterized for their surface morphology, water contact angle, thickness, porosity, pore size and pore size distribution. The DCMD process performance was optimized using a locally designed and fabricated module aiming to maximize the flux at different levels of operating parameters, mainly feed water and coolant inlet temperatures at different temperature differences across the membrane (δT). Water vapor flux of 88.8kg/m2h was obtained using a PTFE membrane at high δT (60°C). In addition, the flux performance was compared to the first generation of a new locally synthesized and fabricated membrane made of a different class of polymer under the same conditions. A total salt rejection of 99.99% and boron rejection of 99.41% were achieved under extreme operating conditions. On the other hand, a detailed water characterization revealed that low molecular weight non-ionic molecules (ppb level) were transported with the water vapor molecules through the membrane structure. The membrane which provided the highest flux was then tested under large scale module operating conditions. The average flux of the latter study (low δT) was found to be eight times lower than that of the bench scale (high δT) operating conditions.

Performance evaluation of the DCMD desalination process under bench scale and large scale module operating conditions

KAUST Repository

Francis, Lijo; Ghaffour, NorEddine; Alsaadi, Ahmad Salem; Nunes, Suzana Pereira; Amy, Gary L.

2014-01-01

The flux performance of different hydrophobic microporous flat sheet commercial membranes made of poly tetrafluoroethylene (PTFE) and poly propylene (PP) was tested for Red Sea water desalination using the direct contact membrane distillation (DCMD) process, under bench scale (high δT) and large scale module (low δT) operating conditions. Membranes were characterized for their surface morphology, water contact angle, thickness, porosity, pore size and pore size distribution. The DCMD process performance was optimized using a locally designed and fabricated module aiming to maximize the flux at different levels of operating parameters, mainly feed water and coolant inlet temperatures at different temperature differences across the membrane (δT). Water vapor flux of 88.8kg/m2h was obtained using a PTFE membrane at high δT (60°C). In addition, the flux performance was compared to the first generation of a new locally synthesized and fabricated membrane made of a different class of polymer under the same conditions. A total salt rejection of 99.99% and boron rejection of 99.41% were achieved under extreme operating conditions. On the other hand, a detailed water characterization revealed that low molecular weight non-ionic molecules (ppb level) were transported with the water vapor molecules through the membrane structure. The membrane which provided the highest flux was then tested under large scale module operating conditions. The average flux of the latter study (low δT) was found to be eight times lower than that of the bench scale (high δT) operating conditions.

Performance Modeling of Hybrid MPI/OpenMP Scientific Applications on Large-scale Multicore Cluster Systems

KAUST Repository

Wu, Xingfu; Taylor, Valerie

2011-01-01

In this paper, we present a performance modeling framework based on memory bandwidth contention time and a parameterized communication model to predict the performance of OpenMP, MPI and hybrid applications with weak scaling on three large-scale multicore clusters: IBM POWER4, POWER5+ and Blue Gene/P, and analyze the performance of these MPI, OpenMP and hybrid applications. We use STREAM memory benchmarks to provide initial performance analysis and model validation of MPI and OpenMP applications on these multicore clusters because the measured sustained memory bandwidth can provide insight into the memory bandwidth that a system should sustain on scientific applications with the same amount of workload per core. In addition to using these benchmarks, we also use a weak-scaling hybrid MPI/OpenMP large-scale scientific application: Gyro kinetic Toroidal Code in magnetic fusion to validate our performance model of the hybrid application on these multicore clusters. The validation results for our performance modeling method show less than 7.77% error rate in predicting the performance of hybrid MPI/OpenMP GTC on up to 512 cores on these multicore clusters. © 2011 IEEE.

Performance Modeling of Hybrid MPI/OpenMP Scientific Applications on Large-scale Multicore Cluster Systems

KAUST Repository

Wu, Xingfu

2011-08-01

In this paper, we present a performance modeling framework based on memory bandwidth contention time and a parameterized communication model to predict the performance of OpenMP, MPI and hybrid applications with weak scaling on three large-scale multicore clusters: IBM POWER4, POWER5+ and Blue Gene/P, and analyze the performance of these MPI, OpenMP and hybrid applications. We use STREAM memory benchmarks to provide initial performance analysis and model validation of MPI and OpenMP applications on these multicore clusters because the measured sustained memory bandwidth can provide insight into the memory bandwidth that a system should sustain on scientific applications with the same amount of workload per core. In addition to using these benchmarks, we also use a weak-scaling hybrid MPI/OpenMP large-scale scientific application: Gyro kinetic Toroidal Code in magnetic fusion to validate our performance model of the hybrid application on these multicore clusters. The validation results for our performance modeling method show less than 7.77% error rate in predicting the performance of hybrid MPI/OpenMP GTC on up to 512 cores on these multicore clusters. © 2011 IEEE.

Seismic safety in conducting large-scale blasts

Science.gov (United States)

Mashukov, I. V.; Chaplygin, V. V.; Domanov, V. P.; Semin, A. A.; Klimkin, M. A.

2017-09-01

In mining enterprises to prepare hard rocks for excavation a drilling and blasting method is used. With the approach of mining operations to settlements the negative effect of large-scale blasts increases. To assess the level of seismic impact of large-scale blasts the scientific staff of Siberian State Industrial University carried out expertise for coal mines and iron ore enterprises. Determination of the magnitude of surface seismic vibrations caused by mass explosions was performed using seismic receivers, an analog-digital converter with recording on a laptop. The registration results of surface seismic vibrations during production of more than 280 large-scale blasts at 17 mining enterprises in 22 settlements are presented. The maximum velocity values of the Earth’s surface vibrations are determined. The safety evaluation of seismic effect was carried out according to the permissible value of vibration velocity. For cases with exceedance of permissible values recommendations were developed to reduce the level of seismic impact.

Large scale network-centric distributed systems

CERN Document Server

Sarbazi-Azad, Hamid

2014-01-01

A highly accessible reference offering a broad range of topics and insights on large scale network-centric distributed systems Evolving from the fields of high-performance computing and networking, large scale network-centric distributed systems continues to grow as one of the most important topics in computing and communication and many interdisciplinary areas. Dealing with both wired and wireless networks, this book focuses on the design and performance issues of such systems. Large Scale Network-Centric Distributed Systems provides in-depth coverage ranging from ground-level hardware issu

Understanding water delivery performance in a large-scale irrigation system in Peru

NARCIS (Netherlands)

Vos, J.M.C.

2005-01-01

During a two-year field study the performance of the water delivery was evaluated in a large-scale irrigation system on the north coast of Peru. Flow measurements were carried out along the main canals, along two secondary canals, and in two tertiary blocks in the Chancay-Lambayeque irrigation

Large-scale derived flood frequency analysis based on continuous simulation

Science.gov (United States)

Dung Nguyen, Viet; Hundecha, Yeshewatesfa; Guse, Björn; Vorogushyn, Sergiy; Merz, Bruno

2016-04-01

There is an increasing need for spatially consistent flood risk assessments at the regional scale (several 100.000 km2), in particular in the insurance industry and for national risk reduction strategies. However, most large-scale flood risk assessments are composed of smaller-scale assessments and show spatial inconsistencies. To overcome this deficit, a large-scale flood model composed of a weather generator and catchments models was developed reflecting the spatially inherent heterogeneity. The weather generator is a multisite and multivariate stochastic model capable of generating synthetic meteorological fields (precipitation, temperature, etc.) at daily resolution for the regional scale. These fields respect the observed autocorrelation, spatial correlation and co-variance between the variables. They are used as input into catchment models. A long-term simulation of this combined system enables to derive very long discharge series at many catchment locations serving as a basic for spatially consistent flood risk estimates at the regional scale. This combined model was set up and validated for major river catchments in Germany. The weather generator was trained by 53-year observation data at 528 stations covering not only the complete Germany but also parts of France, Switzerland, Czech Republic and Australia with the aggregated spatial scale of 443,931 km2. 10.000 years of daily meteorological fields for the study area were generated. Likewise, rainfall-runoff simulations with SWIM were performed for the entire Elbe, Rhine, Weser, Donau and Ems catchments. The validation results illustrate a good performance of the combined system, as the simulated flood magnitudes and frequencies agree well with the observed flood data. Based on continuous simulation this model chain is then used to estimate flood quantiles for the whole Germany including upstream headwater catchments in neighbouring countries. This continuous large scale approach overcomes the several

Linking Large-Scale Reading Assessments: Comment

Science.gov (United States)

Hanushek, Eric A.

2016-01-01

E. A. Hanushek points out in this commentary that applied researchers in education have only recently begun to appreciate the value of international assessments, even though there are now 50 years of experience with these. Until recently, these assessments have been stand-alone surveys that have not been linked, and analysis has largely focused on…

Environmental performance evaluation of large-scale municipal solid waste incinerators using data envelopment analysis

International Nuclear Information System (INIS)

Chen, H.-W.; Chang, N.-B.; Chen, J.-C.; Tsai, S.-J.

2010-01-01

Limited to insufficient land resources, incinerators are considered in many countries such as Japan and Germany as the major technology for a waste management scheme capable of dealing with the increasing demand for municipal and industrial solid waste treatment in urban regions. The evaluation of these municipal incinerators in terms of secondary pollution potential, cost-effectiveness, and operational efficiency has become a new focus in the highly interdisciplinary area of production economics, systems analysis, and waste management. This paper aims to demonstrate the application of data envelopment analysis (DEA) - a production economics tool - to evaluate performance-based efficiencies of 19 large-scale municipal incinerators in Taiwan with different operational conditions. A 4-year operational data set from 2002 to 2005 was collected in support of DEA modeling using Monte Carlo simulation to outline the possibility distributions of operational efficiency of these incinerators. Uncertainty analysis using the Monte Carlo simulation provides a balance between simplifications of our analysis and the soundness of capturing the essential random features that complicate solid waste management systems. To cope with future challenges, efforts in the DEA modeling, systems analysis, and prediction of the performance of large-scale municipal solid waste incinerators under normal operation and special conditions were directed toward generating a compromised assessment procedure. Our research findings will eventually lead to the identification of the optimal management strategies for promoting the quality of solid waste incineration, not only in Taiwan, but also elsewhere in the world.

Performance of mushroom fruiting for large scale commercial production

International Nuclear Information System (INIS)

Mat Rosol Awang; Rosnani Abdul Rashid; Hassan Hamdani Mutaat; Mohd Meswan Maskom

2012-01-01

The paper described the determination of mushroom fruiting yield, which is vital to economics of mushroom production. Consistency in mushroom yields enabling an estimation to be made for revenues and hence profitability could be predicted. It has been reported by many growers, there are a large variation in mushroom yields over different times of production. To assess such claims we have run four batches of mushroom fruiting and the performance fruiting body productions are presented. (author)

A large-scale examination of the effectiveness of anonymous marking in reducing group performance differences in higher education assessment.

Directory of Open Access Journals (Sweden)

Daniel P Hinton

Full Text Available The present research aims to more fully explore the issues of performance differences in higher education assessment, particularly in the context of a common measure taken to address them. The rationale for the study is that, while performance differences in written examinations are relatively well researched, few studies have examined the efficacy of anonymous marking in reducing these performance differences, particularly in modern student populations. By examining a large archive (N = 30674 of assessment data spanning a twelve-year period, the relationship between assessment marks and factors such as ethnic group, gender and socio-environmental background was investigated. In particular, analysis focused on the impact that the implementation of anonymous marking for assessment of written examinations and coursework has had on the magnitude of mean score differences between demographic groups of students. While group differences were found to be pervasive in higher education assessment, these differences were observed to be relatively small in practical terms. Further, it appears that the introduction of anonymous marking has had a negligible effect in reducing them. The implications of these results are discussed, focusing on two issues, firstly a defence of examinations as a fair and legitimate form of assessment in Higher Education, and, secondly, a call for the re-examination of the efficacy of anonymous marking in reducing group performance differences.

A large-scale examination of the effectiveness of anonymous marking in reducing group performance differences in higher education assessment.

Science.gov (United States)

Hinton, Daniel P; Higson, Helen

2017-01-01

The present research aims to more fully explore the issues of performance differences in higher education assessment, particularly in the context of a common measure taken to address them. The rationale for the study is that, while performance differences in written examinations are relatively well researched, few studies have examined the efficacy of anonymous marking in reducing these performance differences, particularly in modern student populations. By examining a large archive (N = 30674) of assessment data spanning a twelve-year period, the relationship between assessment marks and factors such as ethnic group, gender and socio-environmental background was investigated. In particular, analysis focused on the impact that the implementation of anonymous marking for assessment of written examinations and coursework has had on the magnitude of mean score differences between demographic groups of students. While group differences were found to be pervasive in higher education assessment, these differences were observed to be relatively small in practical terms. Further, it appears that the introduction of anonymous marking has had a negligible effect in reducing them. The implications of these results are discussed, focusing on two issues, firstly a defence of examinations as a fair and legitimate form of assessment in Higher Education, and, secondly, a call for the re-examination of the efficacy of anonymous marking in reducing group performance differences.

The Convergence of High Performance Computing and Large Scale Data Analytics

Science.gov (United States)

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

2015-12-01

As the combinations of remote sensing observations and model outputs have grown, scientists are increasingly burdened with both the necessity and complexity of large-scale data analysis. Scientists are increasingly applying traditional high performance computing (HPC) solutions to solve their "Big Data" problems. While this approach has the benefit of limiting data movement, the HPC system is not optimized to run analytics, which can create problems that permeate throughout the HPC environment. To solve these issues and to alleviate some of the strain on the HPC environment, the NASA Center for Climate Simulation (NCCS) has created the Advanced Data Analytics Platform (ADAPT), which combines both HPC and cloud technologies to create an agile system designed for analytics. Large, commonly used data sets are stored in this system in a write once/read many file system, such as Landsat, MODIS, MERRA, and NGA. High performance virtual machines are deployed and scaled according to the individual scientist's requirements specifically for data analysis. On the software side, the NCCS and GMU are working with emerging commercial technologies and applying them to structured, binary scientific data in order to expose the data in new ways. Native NetCDF data is being stored within a Hadoop Distributed File System (HDFS) enabling storage-proximal processing through MapReduce while continuing to provide accessibility of the data to traditional applications. Once the data is stored within HDFS, an additional indexing scheme is built on top of the data and placed into a relational database. This spatiotemporal index enables extremely fast mappings of queries to data locations to dramatically speed up analytics. These are some of the first steps toward a single unified platform that optimizes for both HPC and large-scale data analysis, and this presentation will elucidate the resulting and necessary exascale architectures required for future systems.

Towards large scale stochastic rainfall models for flood risk assessment in trans-national basins

Science.gov (United States)

Serinaldi, F.; Kilsby, C. G.

2012-04-01

While extensive research has been devoted to rainfall-runoff modelling for risk assessment in small and medium size watersheds, less attention has been paid, so far, to large scale trans-national basins, where flood events have severe societal and economic impacts with magnitudes quantified in billions of Euros. As an example, in the April 2006 flood events along the Danube basin at least 10 people lost their lives and up to 30 000 people were displaced, with overall damages estimated at more than half a billion Euros. In this context, refined analytical methods are fundamental to improve the risk assessment and, then, the design of structural and non structural measures of protection, such as hydraulic works and insurance/reinsurance policies. Since flood events are mainly driven by exceptional rainfall events, suitable characterization and modelling of space-time properties of rainfall fields is a key issue to perform a reliable flood risk analysis based on alternative precipitation scenarios to be fed in a new generation of large scale rainfall-runoff models. Ultimately, this approach should be extended to a global flood risk model. However, as the need of rainfall models able to account for and simulate spatio-temporal properties of rainfall fields over large areas is rather new, the development of new rainfall simulation frameworks is a challenging task involving that faces with the problem of overcoming the drawbacks of the existing modelling schemes (devised for smaller spatial scales), but keeping the desirable properties. In this study, we critically summarize the most widely used approaches for rainfall simulation. Focusing on stochastic approaches, we stress the importance of introducing suitable climate forcings in these simulation schemes in order to account for the physical coherence of rainfall fields over wide areas. Based on preliminary considerations, we suggest a modelling framework relying on the Generalized Additive Models for Location, Scale

Environmental performance evaluation of large-scale municipal solid waste incinerators using data envelopment analysis.

Science.gov (United States)

Chen, Ho-Wen; Chang, Ni-Bin; Chen, Jeng-Chung; Tsai, Shu-Ju

2010-07-01

Limited to insufficient land resources, incinerators are considered in many countries such as Japan and Germany as the major technology for a waste management scheme capable of dealing with the increasing demand for municipal and industrial solid waste treatment in urban regions. The evaluation of these municipal incinerators in terms of secondary pollution potential, cost-effectiveness, and operational efficiency has become a new focus in the highly interdisciplinary area of production economics, systems analysis, and waste management. This paper aims to demonstrate the application of data envelopment analysis (DEA)--a production economics tool--to evaluate performance-based efficiencies of 19 large-scale municipal incinerators in Taiwan with different operational conditions. A 4-year operational data set from 2002 to 2005 was collected in support of DEA modeling using Monte Carlo simulation to outline the possibility distributions of operational efficiency of these incinerators. Uncertainty analysis using the Monte Carlo simulation provides a balance between simplifications of our analysis and the soundness of capturing the essential random features that complicate solid waste management systems. To cope with future challenges, efforts in the DEA modeling, systems analysis, and prediction of the performance of large-scale municipal solid waste incinerators under normal operation and special conditions were directed toward generating a compromised assessment procedure. Our research findings will eventually lead to the identification of the optimal management strategies for promoting the quality of solid waste incineration, not only in Taiwan, but also elsewhere in the world. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Free Global Dsm Assessment on Large Scale Areas Exploiting the Potentialities of the Innovative Google Earth Engine Platform

Science.gov (United States)

Nascetti, A.; Di Rita, M.; Ravanelli, R.; Amicuzi, M.; Esposito, S.; Crespi, M.

2017-05-01

The high-performance cloud-computing platform Google Earth Engine has been developed for global-scale analysis based on the Earth observation data. In particular, in this work, the geometric accuracy of the two most used nearly-global free DSMs (SRTM and ASTER) has been evaluated on the territories of four American States (Colorado, Michigan, Nevada, Utah) and one Italian Region (Trentino Alto- Adige, Northern Italy) exploiting the potentiality of this platform. These are large areas characterized by different terrain morphology, land covers and slopes. The assessment has been performed using two different reference DSMs: the USGS National Elevation Dataset (NED) and a LiDAR acquisition. The DSMs accuracy has been evaluated through computation of standard statistic parameters, both at global scale (considering the whole State/Region) and in function of the terrain morphology using several slope classes. The geometric accuracy in terms of Standard deviation and NMAD, for SRTM range from 2-3 meters in the first slope class to about 45 meters in the last one, whereas for ASTER, the values range from 5-6 to 30 meters. In general, the performed analysis shows a better accuracy for the SRTM in the flat areas whereas the ASTER GDEM is more reliable in the steep areas, where the slopes increase. These preliminary results highlight the GEE potentialities to perform DSM assessment on a global scale.

FREE GLOBAL DSM ASSESSMENT ON LARGE SCALE AREAS EXPLOITING THE POTENTIALITIES OF THE INNOVATIVE GOOGLE EARTH ENGINE PLATFORM

Directory of Open Access Journals (Sweden)

A. Nascetti

2017-05-01

Full Text Available The high-performance cloud-computing platform Google Earth Engine has been developed for global-scale analysis based on the Earth observation data. In particular, in this work, the geometric accuracy of the two most used nearly-global free DSMs (SRTM and ASTER has been evaluated on the territories of four American States (Colorado, Michigan, Nevada, Utah and one Italian Region (Trentino Alto- Adige, Northern Italy exploiting the potentiality of this platform. These are large areas characterized by different terrain morphology, land covers and slopes. The assessment has been performed using two different reference DSMs: the USGS National Elevation Dataset (NED and a LiDAR acquisition. The DSMs accuracy has been evaluated through computation of standard statistic parameters, both at global scale (considering the whole State/Region and in function of the terrain morphology using several slope classes. The geometric accuracy in terms of Standard deviation and NMAD, for SRTM range from 2-3 meters in the first slope class to about 45 meters in the last one, whereas for ASTER, the values range from 5-6 to 30 meters. In general, the performed analysis shows a better accuracy for the SRTM in the flat areas whereas the ASTER GDEM is more reliable in the steep areas, where the slopes increase. These preliminary results highlight the GEE potentialities to perform DSM assessment on a global scale.

Towards Portable Large-Scale Image Processing with High-Performance Computing.

Science.gov (United States)

Huo, Yuankai; Blaber, Justin; Damon, Stephen M; Boyd, Brian D; Bao, Shunxing; Parvathaneni, Prasanna; Noguera, Camilo Bermudez; Chaganti, Shikha; Nath, Vishwesh; Greer, Jasmine M; Lyu, Ilwoo; French, William R; Newton, Allen T; Rogers, Baxter P; Landman, Bennett A

2018-05-03

High-throughput, large-scale medical image computing demands tight integration of high-performance computing (HPC) infrastructure for data storage, job distribution, and image processing. The Vanderbilt University Institute for Imaging Science (VUIIS) Center for Computational Imaging (CCI) has constructed a large-scale image storage and processing infrastructure that is composed of (1) a large-scale image database using the eXtensible Neuroimaging Archive Toolkit (XNAT), (2) a content-aware job scheduling platform using the Distributed Automation for XNAT pipeline automation tool (DAX), and (3) a wide variety of encapsulated image processing pipelines called "spiders." The VUIIS CCI medical image data storage and processing infrastructure have housed and processed nearly half-million medical image volumes with Vanderbilt Advanced Computing Center for Research and Education (ACCRE), which is the HPC facility at the Vanderbilt University. The initial deployment was natively deployed (i.e., direct installations on a bare-metal server) within the ACCRE hardware and software environments, which lead to issues of portability and sustainability. First, it could be laborious to deploy the entire VUIIS CCI medical image data storage and processing infrastructure to another HPC center with varying hardware infrastructure, library availability, and software permission policies. Second, the spiders were not developed in an isolated manner, which has led to software dependency issues during system upgrades or remote software installation. To address such issues, herein, we describe recent innovations using containerization techniques with XNAT/DAX which are used to isolate the VUIIS CCI medical image data storage and processing infrastructure from the underlying hardware and software environments. The newly presented XNAT/DAX solution has the following new features: (1) multi-level portability from system level to the application level, (2) flexible and dynamic software

Including Performance Assessments in Accountability Systems: A Review of Scale-Up Efforts

Science.gov (United States)

Tung, Rosann

2010-01-01

The purpose of this literature and field review is to understand previous efforts at scaling up performance assessments for use across districts and states. Performance assessments benefit students and teachers by providing more opportunities for students to demonstrate their knowledge and complex skills, by providing teachers with better…

How to Measure and Explain Achievement Change in Large-Scale Assessments: A Rejoinder

Science.gov (United States)

Hickendorff, Marian; Heiser, Willem J.; van Putten, Cornelis M.; Verhelst, Norman D.

2009-01-01

In this rejoinder, we discuss substantive and methodological validity issues of large-scale assessments of trends in student achievement, commenting on the discussion paper by Van den Heuvel-Panhuizen, Robitzsch, Treffers, and Koller (2009). We focus on methodological challenges in deciding what to measure, how to measure it, and how to foster…

Large scale model testing

International Nuclear Information System (INIS)

Brumovsky, M.; Filip, R.; Polachova, H.; Stepanek, S.

1989-01-01

Fracture mechanics and fatigue calculations for WWER reactor pressure vessels were checked by large scale model testing performed using large testing machine ZZ 8000 (with a maximum load of 80 MN) at the SKODA WORKS. The results are described from testing the material resistance to fracture (non-ductile). The testing included the base materials and welded joints. The rated specimen thickness was 150 mm with defects of a depth between 15 and 100 mm. The results are also presented of nozzles of 850 mm inner diameter in a scale of 1:3; static, cyclic, and dynamic tests were performed without and with surface defects (15, 30 and 45 mm deep). During cyclic tests the crack growth rate in the elastic-plastic region was also determined. (author). 6 figs., 2 tabs., 5 refs

VESPA: Very large-scale Evolutionary and Selective Pressure Analyses

Directory of Open Access Journals (Sweden)

Andrew E. Webb

2017-06-01

Full Text Available Background Large-scale molecular evolutionary analyses of protein coding sequences requires a number of preparatory inter-related steps from finding gene families, to generating alignments and phylogenetic trees and assessing selective pressure variation. Each phase of these analyses can represent significant challenges, particularly when working with entire proteomes (all protein coding sequences in a genome from a large number of species. Methods We present VESPA, software capable of automating a selective pressure analysis using codeML in addition to the preparatory analyses and summary statistics. VESPA is written in python and Perl and is designed to run within a UNIX environment. Results We have benchmarked VESPA and our results show that the method is consistent, performs well on both large scale and smaller scale datasets, and produces results in line with previously published datasets. Discussion Large-scale gene family identification, sequence alignment, and phylogeny reconstruction are all important aspects of large-scale molecular evolutionary analyses. VESPA provides flexible software for simplifying these processes along with downstream selective pressure variation analyses. The software automatically interprets results from codeML and produces simplified summary files to assist the user in better understanding the results. VESPA may be found at the following website: http://www.mol-evol.org/VESPA.

``Large''- vs Small-scale friction control in turbulent channel flow

Science.gov (United States)

Canton, Jacopo; Örlü, Ramis; Chin, Cheng; Schlatter, Philipp

2017-11-01

We reconsider the ``large-scale'' control scheme proposed by Hussain and co-workers (Phys. Fluids 10, 1049-1051 1998 and Phys. Rev. Fluids, 2, 62601 2017), using new direct numerical simulations (DNS). The DNS are performed in a turbulent channel at friction Reynolds number Reτ of up to 550 in order to eliminate low-Reynolds-number effects. The purpose of the present contribution is to re-assess this control method in the light of more modern developments in the field, in particular also related to the discovery of (very) large-scale motions. The goals of the paper are as follows: First, we want to better characterise the physics of the control, and assess what external contribution (vortices, forcing, wall motion) are actually needed. Then, we investigate the optimal parameters and, finally, determine which aspects of this control technique actually scale in outer units and can therefore be of use in practical applications. In addition to discussing the mentioned drag-reduction effects, the present contribution will also address the potential effect of the naturally occurring large-scale motions on frictional drag, and give indications on the physical processes for potential drag reduction possible at all Reynolds numbers.

Multiresolution comparison of precipitation datasets for large-scale models

Science.gov (United States)

Chun, K. P.; Sapriza Azuri, G.; Davison, B.; DeBeer, C. M.; Wheater, H. S.

2014-12-01

Gridded precipitation datasets are crucial for driving large-scale models which are related to weather forecast and climate research. However, the quality of precipitation products is usually validated individually. Comparisons between gridded precipitation products along with ground observations provide another avenue for investigating how the precipitation uncertainty would affect the performance of large-scale models. In this study, using data from a set of precipitation gauges over British Columbia and Alberta, we evaluate several widely used North America gridded products including the Canadian Gridded Precipitation Anomalies (CANGRD), the National Center for Environmental Prediction (NCEP) reanalysis, the Water and Global Change (WATCH) project, the thin plate spline smoothing algorithms (ANUSPLIN) and Canadian Precipitation Analysis (CaPA). Based on verification criteria for various temporal and spatial scales, results provide an assessment of possible applications for various precipitation datasets. For long-term climate variation studies (~100 years), CANGRD, NCEP, WATCH and ANUSPLIN have different comparative advantages in terms of their resolution and accuracy. For synoptic and mesoscale precipitation patterns, CaPA provides appealing performance of spatial coherence. In addition to the products comparison, various downscaling methods are also surveyed to explore new verification and bias-reduction methods for improving gridded precipitation outputs for large-scale models.

Lessons from a large-scale assessment: Results from conceptual inventories

Directory of Open Access Journals (Sweden)

Beth Thacker

2014-07-01

Full Text Available We report conceptual inventory results of a large-scale assessment project at a large university. We studied the introduction of materials and instructional methods informed by physics education research (PER (physics education research-informed materials into a department where most instruction has previously been traditional and a significant number of faculty are hesitant, ambivalent, or even resistant to the introduction of such reforms. Data were collected in all of the sections of both the large algebra- and calculus-based introductory courses for a number of years employing commonly used conceptual inventories. Results from a small PER-informed, inquiry-based, laboratory-based class are also reported. Results suggest that when PER-informed materials are introduced in the labs and recitations, independent of the lecture style, there is an increase in students’ conceptual inventory gains. There is also an increase in the results on conceptual inventories if PER-informed instruction is used in the lecture. The highest conceptual inventory gains were achieved by the combination of PER-informed lectures and laboratories in large class settings and by the hands-on, laboratory-based, inquiry-based course taught in a small class setting.

Large-scale solar heat

Energy Technology Data Exchange (ETDEWEB)

Tolonen, J.; Konttinen, P.; Lund, P. [Helsinki Univ. of Technology, Otaniemi (Finland). Dept. of Engineering Physics and Mathematics

1998-12-31

In this project a large domestic solar heating system was built and a solar district heating system was modelled and simulated. Objectives were to improve the performance and reduce costs of a large-scale solar heating system. As a result of the project the benefit/cost ratio can be increased by 40 % through dimensioning and optimising the system at the designing stage. (orig.)

Large-scale assessment of flood risk and the effects of mitigation measures along the Elbe River

NARCIS (Netherlands)

de Kok, Jean-Luc; Grossmann, M.

2010-01-01

The downstream effects of flood risk mitigation measures and the necessity to develop flood risk management strategies that are effective on a basin scale call for a flood risk assessment methodology that can be applied at the scale of a large river. We present an example of a rapid flood risk

Large-scale model-based assessment of deer-vehicle collision risk.

Directory of Open Access Journals (Sweden)

Torsten Hothorn

Full Text Available Ungulates, in particular the Central European roe deer Capreolus capreolus and the North American white-tailed deer Odocoileus virginianus, are economically and ecologically important. The two species are risk factors for deer-vehicle collisions and as browsers of palatable trees have implications for forest regeneration. However, no large-scale management systems for ungulates have been implemented, mainly because of the high efforts and costs associated with attempts to estimate population sizes of free-living ungulates living in a complex landscape. Attempts to directly estimate population sizes of deer are problematic owing to poor data quality and lack of spatial representation on larger scales. We used data on >74,000 deer-vehicle collisions observed in 2006 and 2009 in Bavaria, Germany, to model the local risk of deer-vehicle collisions and to investigate the relationship between deer-vehicle collisions and both environmental conditions and browsing intensities. An innovative modelling approach for the number of deer-vehicle collisions, which allows nonlinear environment-deer relationships and assessment of spatial heterogeneity, was the basis for estimating the local risk of collisions for specific road types on the scale of Bavarian municipalities. Based on this risk model, we propose a new "deer-vehicle collision index" for deer management. We show that the risk of deer-vehicle collisions is positively correlated to browsing intensity and to harvest numbers. Overall, our results demonstrate that the number of deer-vehicle collisions can be predicted with high precision on the scale of municipalities. In the densely populated and intensively used landscapes of Central Europe and North America, a model-based risk assessment for deer-vehicle collisions provides a cost-efficient instrument for deer management on the landscape scale. The measures derived from our model provide valuable information for planning road protection and defining

Stereotype Threat, Inquiring about Test Takers' Race and Gender, and Performance on Low-Stakes Tests in a Large-Scale Assessment. Research Report. ETS RR-15-02

Science.gov (United States)

Stricker, Lawrence J.; Rock, Donald A.; Bridgeman, Brent

2015-01-01

This study explores stereotype threat on low-stakes tests used in a large-scale assessment, math and reading tests in the Education Longitudinal Study of 2002 (ELS). Issues identified in laboratory research (though not observed in studies of high-stakes tests) were assessed: whether inquiring about their race and gender is related to the…

A new method for large-scale assessment of change in ecosystem functioning in relation to land degradation

Science.gov (United States)

Horion, Stephanie; Ivits, Eva; Verzandvoort, Simone; Fensholt, Rasmus

2017-04-01

Ongoing pressures on European land are manifold with extreme climate events and non-sustainable use of land resources being amongst the most important drivers altering the functioning of the ecosystems. The protection and conservation of European natural capital is one of the key objectives of the 7th Environmental Action Plan (EAP). The EAP stipulates that European land must be managed in a sustainable way by 2020 and the UN Sustainable development goals define a Land Degradation Neutral world as one of the targets. This implies that land degradation (LD) assessment of European ecosystems must be performed repeatedly allowing for the assessment of the current state of LD as well as changes compared to a baseline adopted by the UNCCD for the objective of land degradation neutrality. However, scientifically robust methods are still lacking for large-scale assessment of LD and repeated consistent mapping of the state of terrestrial ecosystems. Historical land degradation assessments based on various methods exist, but methods are generally non-replicable or difficult to apply at continental scale (Allan et al. 2007). The current lack of research methods applicable at large spatial scales is notably caused by the non-robust definition of LD, the scarcity of field data on LD, as well as the complex inter-play of the processes driving LD (Vogt et al., 2011). Moreover, the link between LD and changes in land use (how land use changes relates to change in vegetation productivity and ecosystem functioning) is not straightforward. In this study we used the segmented trend method developed by Horion et al. (2016) for large-scale systematic assessment of hotspots of change in ecosystem functioning in relation to LD. This method alleviates shortcomings of widely used linear trend model that does not account for abrupt change, nor adequately captures the actual changes in ecosystem functioning (de Jong et al. 2013; Horion et al. 2016). Here we present a new methodology for

Large scale chromatographic separations using continuous displacement chromatography (CDC)

International Nuclear Information System (INIS)

Taniguchi, V.T.; Doty, A.W.; Byers, C.H.

1988-01-01

A process for large scale chromatographic separations using a continuous chromatography technique is described. The process combines the advantages of large scale batch fixed column displacement chromatography with conventional analytical or elution continuous annular chromatography (CAC) to enable large scale displacement chromatography to be performed on a continuous basis (CDC). Such large scale, continuous displacement chromatography separations have not been reported in the literature. The process is demonstrated with the ion exchange separation of a binary lanthanide (Nd/Pr) mixture. The process is, however, applicable to any displacement chromatography separation that can be performed using conventional batch, fixed column chromatography

Performance Evaluation of Hadoop-based Large-scale Network Traffic Analysis Cluster

Directory of Open Access Journals (Sweden)

Tao Ran

2016-01-01

Full Text Available As Hadoop has gained popularity in big data era, it is widely used in various fields. The self-design and self-developed large-scale network traffic analysis cluster works well based on Hadoop, with off-line applications running on it to analyze the massive network traffic data. On purpose of scientifically and reasonably evaluating the performance of analysis cluster, we propose a performance evaluation system. Firstly, we set the execution times of three benchmark applications as the benchmark of the performance, and pick 40 metrics of customized statistical resource data. Then we identify the relationship between the resource data and the execution times by a statistic modeling analysis approach, which is composed of principal component analysis and multiple linear regression. After training models by historical data, we can predict the execution times by current resource data. Finally, we evaluate the performance of analysis cluster by the validated predicting of execution times. Experimental results show that the predicted execution times by trained models are within acceptable error range, and the evaluation results of performance are accurate and reliable.

On-line transient stability assessment of large-scale power systems by using ball vector machines

International Nuclear Information System (INIS)

Mohammadi, M.; Gharehpetian, G.B.

2010-01-01

In this paper ball vector machine (BVM) has been used for on-line transient stability assessment of large-scale power systems. To classify the system transient security status, a BVM has been trained for all contingencies. The proposed BVM based security assessment algorithm has very small training time and space in comparison with artificial neural networks (ANN), support vector machines (SVM) and other machine learning based algorithms. In addition, the proposed algorithm has less support vectors (SV) and therefore is faster than existing algorithms for on-line applications. One of the main points, to apply a machine learning method is feature selection. In this paper, a new Decision Tree (DT) based feature selection technique has been presented. The proposed BVM based algorithm has been applied to New England 39-bus power system. The simulation results show the effectiveness and the stability of the proposed method for on-line transient stability assessment procedure of large-scale power system. The proposed feature selection algorithm has been compared with different feature selection algorithms. The simulation results demonstrate the effectiveness of the proposed feature algorithm.

Balancing Tensions in Educational Policy Reforms: Large-Scale Implementation of Assessment for Learning in Norway

Science.gov (United States)

Hopfenbeck, Therese N.; Flórez Petour, María Teresa; Tolo, Astrid

2015-01-01

This study investigates how different stakeholders in Norway experienced a government-initiated, large-scale policy implementation programme on "Assessment for Learning" ("AfL"). Data were collected through 58 interviews with stakeholders in charge of the policy; Ministers of Education and members of the Directorate of…

Comparison Between Overtopping Discharge in Small and Large Scale Models

DEFF Research Database (Denmark)

Helgason, Einar; Burcharth, Hans F.

2006-01-01

The present paper presents overtopping measurements from small scale model test performed at the Haudraulic & Coastal Engineering Laboratory, Aalborg University, Denmark and large scale model tests performed at the Largde Wave Channel,Hannover, Germany. Comparison between results obtained from...... small and large scale model tests show no clear evidence of scale effects for overtopping above a threshold value. In the large scale model no overtopping was measured for waveheights below Hs = 0.5m as the water sunk into the voids between the stones on the crest. For low overtopping scale effects...

Fast Simulation of Large-Scale Floods Based on GPU Parallel Computing

Directory of Open Access Journals (Sweden)

Qiang Liu

2018-05-01

Full Text Available Computing speed is a significant issue of large-scale flood simulations for real-time response to disaster prevention and mitigation. Even today, most of the large-scale flood simulations are generally run on supercomputers due to the massive amounts of data and computations necessary. In this work, a two-dimensional shallow water model based on an unstructured Godunov-type finite volume scheme was proposed for flood simulation. To realize a fast simulation of large-scale floods on a personal computer, a Graphics Processing Unit (GPU-based, high-performance computing method using the OpenACC application was adopted to parallelize the shallow water model. An unstructured data management method was presented to control the data transportation between the GPU and CPU (Central Processing Unit with minimum overhead, and then both computation and data were offloaded from the CPU to the GPU, which exploited the computational capability of the GPU as much as possible. The parallel model was validated using various benchmarks and real-world case studies. The results demonstrate that speed-ups of up to one order of magnitude can be achieved in comparison with the serial model. The proposed parallel model provides a fast and reliable tool with which to quickly assess flood hazards in large-scale areas and, thus, has a bright application prospect for dynamic inundation risk identification and disaster assessment.

A new asynchronous parallel algorithm for inferring large-scale gene regulatory networks.

Directory of Open Access Journals (Sweden)

Xiangyun Xiao

Full Text Available The reconstruction of gene regulatory networks (GRNs from high-throughput experimental data has been considered one of the most important issues in systems biology research. With the development of high-throughput technology and the complexity of biological problems, we need to reconstruct GRNs that contain thousands of genes. However, when many existing algorithms are used to handle these large-scale problems, they will encounter two important issues: low accuracy and high computational cost. To overcome these difficulties, the main goal of this study is to design an effective parallel algorithm to infer large-scale GRNs based on high-performance parallel computing environments. In this study, we proposed a novel asynchronous parallel framework to improve the accuracy and lower the time complexity of large-scale GRN inference by combining splitting technology and ordinary differential equation (ODE-based optimization. The presented algorithm uses the sparsity and modularity of GRNs to split whole large-scale GRNs into many small-scale modular subnetworks. Through the ODE-based optimization of all subnetworks in parallel and their asynchronous communications, we can easily obtain the parameters of the whole network. To test the performance of the proposed approach, we used well-known benchmark datasets from Dialogue for Reverse Engineering Assessments and Methods challenge (DREAM, experimentally determined GRN of Escherichia coli and one published dataset that contains more than 10 thousand genes to compare the proposed approach with several popular algorithms on the same high-performance computing environments in terms of both accuracy and time complexity. The numerical results demonstrate that our parallel algorithm exhibits obvious superiority in inferring large-scale GRNs.

A new asynchronous parallel algorithm for inferring large-scale gene regulatory networks.

Science.gov (United States)

Xiao, Xiangyun; Zhang, Wei; Zou, Xiufen

2015-01-01

The reconstruction of gene regulatory networks (GRNs) from high-throughput experimental data has been considered one of the most important issues in systems biology research. With the development of high-throughput technology and the complexity of biological problems, we need to reconstruct GRNs that contain thousands of genes. However, when many existing algorithms are used to handle these large-scale problems, they will encounter two important issues: low accuracy and high computational cost. To overcome these difficulties, the main goal of this study is to design an effective parallel algorithm to infer large-scale GRNs based on high-performance parallel computing environments. In this study, we proposed a novel asynchronous parallel framework to improve the accuracy and lower the time complexity of large-scale GRN inference by combining splitting technology and ordinary differential equation (ODE)-based optimization. The presented algorithm uses the sparsity and modularity of GRNs to split whole large-scale GRNs into many small-scale modular subnetworks. Through the ODE-based optimization of all subnetworks in parallel and their asynchronous communications, we can easily obtain the parameters of the whole network. To test the performance of the proposed approach, we used well-known benchmark datasets from Dialogue for Reverse Engineering Assessments and Methods challenge (DREAM), experimentally determined GRN of Escherichia coli and one published dataset that contains more than 10 thousand genes to compare the proposed approach with several popular algorithms on the same high-performance computing environments in terms of both accuracy and time complexity. The numerical results demonstrate that our parallel algorithm exhibits obvious superiority in inferring large-scale GRNs.

Use of large-scale acoustic monitoring to assess anthropogenic pressures on Orthoptera communities.

Science.gov (United States)

Penone, Caterina; Le Viol, Isabelle; Pellissier, Vincent; Julien, Jean-François; Bas, Yves; Kerbiriou, Christian

2013-10-01

Biodiversity monitoring at large spatial and temporal scales is greatly needed in the context of global changes. Although insects are a species-rich group and are important for ecosystem functioning, they have been largely neglected in conservation studies and policies, mainly due to technical and methodological constraints. Sound detection, a nondestructive method, is easily applied within a citizen-science framework and could be an interesting solution for insect monitoring. However, it has not yet been tested at a large scale. We assessed the value of a citizen-science program in which Orthoptera species (Tettigoniidae) were monitored acoustically along roads. We used Bayesian model-averaging analyses to test whether we could detect widely known patterns of anthropogenic effects on insects, such as the negative effects of urbanization or intensive agriculture on Orthoptera populations and communities. We also examined site-abundance correlations between years and estimated the biases in species detection to evaluate and improve the protocol. Urbanization and intensive agricultural landscapes negatively affected Orthoptera species richness, diversity, and abundance. This finding is consistent with results of previous studies of Orthoptera, vertebrates, carabids, and butterflies. The average mass of communities decreased as urbanization increased. The dispersal ability of communities increased as the percentage of agricultural land and, to a lesser extent, urban area increased. Despite changes in abundances over time, we found significant correlations between yearly abundances. We identified biases linked to the protocol (e.g., car speed or temperature) that can be accounted for ease in analyses. We argue that acoustic monitoring of Orthoptera along roads offers several advantages for assessing Orthoptera biodiversity at large spatial and temporal extents, particularly in a citizen science framework. © 2013 Society for Conservation Biology.

Co-Cure-Ply Resins for High Performance, Large-Scale Structures

Data.gov (United States)

National Aeronautics and Space Administration — Large-scale composite structures are commonly joined by secondary bonding of molded-and-cured thermoset components. This approach may result in unpredictable joint...

Large-scale Assessment Yields Evidence of Minimal Use of Reasoning Skills in Traditionally Taught Classes

Science.gov (United States)

Thacker, Beth

2017-01-01

Large-scale assessment data from Texas Tech University yielded evidence that most students taught traditionally in large lecture classes with online homework and predominantly multiple choice question exams, when asked to answer free-response (FR) questions, did not support their answers with logical arguments grounded in physics concepts. In addition to a lack of conceptual understanding, incorrect and partially correct answers lacked evidence of the ability to apply even lower level reasoning skills in order to solve a problem. Correct answers, however, did show evidence of at least lower level thinking skills as coded using a rubric based on Bloom's taxonomy. With the introduction of evidence-based instruction into the labs and recitations of the large courses and in a small, completely laboratory-based, hands-on course, the percentage of correct answers with correct explanations increased. The FR format, unlike other assessment formats, allowed assessment of both conceptual understanding and the application of thinking skills, clearly pointing out weaknesses not revealed by other assessment instruments, and providing data on skills beyond conceptual understanding for course and program assessment. Supported by National Institutes of Health (NIH) Challenge grant #1RC1GM090897-01.

New Possibilities for High-Resolution, Large-Scale Ecosystem Assessment of the World's Semi-Arid Regions

Science.gov (United States)

Burney, J. A.; Goldblatt, R.

2016-12-01

Understanding drivers of land use change - and in particular, levels of ecosystem degradation - in semi-arid regions is of critical importance because these agroecosystems (1) are home to the world's poorest populations, almost all of whom depend on agriculture for their livelihoods, (2) play a critical role in the global carbon and climate cycles, and (3) have in many cases seen dramatic changes in temperature and precipitation, relative to global averages, over the past several decades. However, assessing ecosystem health (or, conversely, degradation) presents a difficult measurement problem. Established methods are very labor intensive and rest on detailed questionnaires and field assessments. High-resolution satellite imagery has a unique role semi-arid ecosystem assessment in that it can be used for rapid (or repeated) and very simple measurements of tree and shrub density, an excellent overall indicator for dryland ecosystem health. Because trees and large shrubs are more sparse in semi-arid regions, sub-meter resolution imagery in conjunction with automated image analysis can be used to assess density differences at high spatial resolution without expensive and time-consuming ground-truthing. This could be used down to the farm level, for example, to better assess the larger-scale ecosystem impacts of different management practices, to assess compliance with REDD+ carbon offset protocols, or to evaluate implementation of conservation goals. Here we present results comparing spatial and spectral remote sensing methods for semi-arid ecosystem assessment across new data sources, using the Brazilian Sertão as an example, and the implications for large-scale use in semi-arid ecosystem science.

ORNL Pre-test Analyses of A Large-scale Experiment in STYLE

International Nuclear Information System (INIS)

Williams, Paul T.; Yin, Shengjun; Klasky, Hilda B.; Bass, Bennett Richard

2011-01-01

Oak Ridge National Laboratory (ORNL) is conducting a series of numerical analyses to simulate a large scale mock-up experiment planned within the European Network for Structural Integrity for Lifetime Management non-RPV Components (STYLE). STYLE is a European cooperative effort to assess the structural integrity of (non-reactor pressure vessel) reactor coolant pressure boundary components relevant to ageing and life-time management and to integrate the knowledge created in the project into mainstream nuclear industry assessment codes. ORNL contributes work-in-kind support to STYLE Work Package 2 (Numerical Analysis/Advanced Tools) and Work Package 3 (Engineering Assessment Methods/LBB Analyses). This paper summarizes the current status of ORNL analyses of the STYLE Mock-Up3 large-scale experiment to simulate and evaluate crack growth in a cladded ferritic pipe. The analyses are being performed in two parts. In the first part, advanced fracture mechanics models are being developed and performed to evaluate several experiment designs taking into account the capabilities of the test facility while satisfying the test objectives. Then these advanced fracture mechanics models will be utilized to simulate the crack growth in the large scale mock-up test. For the second part, the recently developed ORNL SIAM-PFM open-source, cross-platform, probabilistic computational tool will be used to generate an alternative assessment for comparison with the advanced fracture mechanics model results. The SIAM-PFM probabilistic analysis of the Mock-Up3 experiment will utilize fracture modules that are installed into a general probabilistic framework. The probabilistic results of the Mock-Up3 experiment obtained from SIAM-PFM will be compared to those results generated using the deterministic 3D nonlinear finite-element modeling approach. The objective of the probabilistic analysis is to provide uncertainty bounds that will assist in assessing the more detailed 3D finite

Improved technique that allows the performance of large-scale SNP genotyping on DNA immobilized by FTA technology.

Science.gov (United States)

He, Hongbin; Argiro, Laurent; Dessein, Helia; Chevillard, Christophe

2007-01-01

FTA technology is a novel method designed to simplify the collection, shipment, archiving and purification of nucleic acids from a wide variety of biological sources. The number of punches that can normally be obtained from a single specimen card are often however, insufficient for the testing of the large numbers of loci required to identify genetic factors that control human susceptibility or resistance to multifactorial diseases. In this study, we propose an improved technique to perform large-scale SNP genotyping. We applied a whole genome amplification method to amplify DNA from buccal cell samples stabilized using FTA technology. The results show that using the improved technique it is possible to perform up to 15,000 genotypes from one buccal cell sample. Furthermore, the procedure is simple. We consider this improved technique to be a promising methods for performing large-scale SNP genotyping because the FTA technology simplifies the collection, shipment, archiving and purification of DNA, while whole genome amplification of FTA card bound DNA produces sufficient material for the determination of thousands of SNP genotypes.

On the use of Cloud Computing and Machine Learning for Large-Scale SAR Science Data Processing and Quality Assessment Analysi

Science.gov (United States)

Hua, H.

2016-12-01

Geodetic imaging is revolutionizing geophysics, but the scope of discovery has been limited by labor-intensive technological implementation of the analyses. The Advanced Rapid Imaging and Analysis (ARIA) project has proven capability to automate SAR data processing and analysis. Existing and upcoming SAR missions such as Sentinel-1A/B and NISAR are also expected to generate massive amounts of SAR data. This has brought to the forefront the need for analytical tools for SAR quality assessment (QA) on the large volumes of SAR data-a critical step before higher-level time series and velocity products can be reliably generated. Initially leveraging an advanced hybrid-cloud computing science data system for performing large-scale processing, machine learning approaches were augmented for automated analysis of various quality metrics. Machine learning-based user-training of features, cross-validation, prediction models were integrated into our cloud-based science data processing flow to enable large-scale and high-throughput QA analytics for enabling improvements to the production quality of geodetic data products.

Amplification of large-scale magnetic field in nonhelical magnetohydrodynamics

KAUST Repository

Kumar, Rohit

2017-08-11

It is typically assumed that the kinetic and magnetic helicities play a crucial role in the growth of large-scale dynamo. In this paper, we demonstrate that helicity is not essential for the amplification of large-scale magnetic field. For this purpose, we perform nonhelical magnetohydrodynamic (MHD) simulation, and show that the large-scale magnetic field can grow in nonhelical MHD when random external forcing is employed at scale 1/10 the box size. The energy fluxes and shell-to-shell transfer rates computed using the numerical data show that the large-scale magnetic energy grows due to the energy transfers from the velocity field at the forcing scales.

Large-scale, high-performance and cloud-enabled multi-model analytics experiments in the context of the Earth System Grid Federation

Science.gov (United States)

Fiore, S.; Płóciennik, M.; Doutriaux, C.; Blanquer, I.; Barbera, R.; Williams, D. N.; Anantharaj, V. G.; Evans, B. J. K.; Salomoni, D.; Aloisio, G.

2017-12-01

The increased models resolution in the development of comprehensive Earth System Models is rapidly leading to very large climate simulations output that pose significant scientific data management challenges in terms of data sharing, processing, analysis, visualization, preservation, curation, and archiving.Large scale global experiments for Climate Model Intercomparison Projects (CMIP) have led to the development of the Earth System Grid Federation (ESGF), a federated data infrastructure which has been serving the CMIP5 experiment, providing access to 2PB of data for the IPCC Assessment Reports. In such a context, running a multi-model data analysis experiment is very challenging, as it requires the availability of a large amount of data related to multiple climate models simulations and scientific data management tools for large-scale data analytics. To address these challenges, a case study on climate models intercomparison data analysis has been defined and implemented in the context of the EU H2020 INDIGO-DataCloud project. The case study has been tested and validated on CMIP5 datasets, in the context of a large scale, international testbed involving several ESGF sites (LLNL, ORNL and CMCC), one orchestrator site (PSNC) and one more hosting INDIGO PaaS services (UPV). Additional ESGF sites, such as NCI (Australia) and a couple more in Europe, are also joining the testbed. The added value of the proposed solution is summarized in the following: it implements a server-side paradigm which limits data movement; it relies on a High-Performance Data Analytics (HPDA) stack to address performance; it exploits the INDIGO PaaS layer to support flexible, dynamic and automated deployment of software components; it provides user-friendly web access based on the INDIGO Future Gateway; and finally it integrates, complements and extends the support currently available through ESGF. Overall it provides a new "tool" for climate scientists to run multi-model experiments. At the

Technical Design Report for large-scale neutrino detectors prototyping and phased performance assessment in view of a long-baseline oscillation experiment

CERN Document Server

De Bonis, I.; Duchesneau, D.; Pessard, H.; Bordoni, S.; Ieva, M.; Lux, T.; Sanchez, F.; Jipa, A.; Lazanu, I.; Calin, M.; Esanu, T.; Ristea, O.; Ristea, C.; Nita, L.; Efthymiopoulos, I.; Nessi, M.; Asfandiyarov, R.; Blondel, A.; Bravar, A.; Cadoux, F.; Haesler, A.; Karadzhov, Y.; Korzenev, A.; Martin, C.; Noah, E.; Ravonel, M.; Rayner, M.; Scantamburlo, E.; Bayes, R.; Soler, F.J.P.; Nuijten, G.A.; Loo, K.; Maalampi, J.; Slupecki, M.; Trzaska, W.H.; Campanelli, M.; Blebea-Apostu, A.M.; Chesneanu, D.; Gomoiu, M.C; Mitrica, B.; Margineanu, R.M.; Stanca, D.L.; Colino, N.; Gil-Botella, I.; Novella, P.; Palomares, C.; Santorelli, R.; Verdugo, A.; Karpikov, I.; Khotjantsev, A.; Kudenko, Y.; Mefodiev, A.; Mineev, O.; Ovsiannikova, T.; Yershov, N.; Enqvist, T.; Kuusiniemi, P.; De La Taille, C.; Dulucq, F.; Martin-Chassard, G.; Andrieu, B.; Dumarchez, J.; Giganti, C.; Levy, J.-M.; Popov, B.; Robert, A.; Agostino, L.; Buizza-Avanzini, M.; Dawson, J.; Franco, D.; Gorodetzky, P.; Kryn, D.; Patzak, T.; Tonazzo, A.; Vannucci, F.; Bésida, O.; Bolognesi, S.; Delbart, A.; Emery, S.; Galymov, V.; Mazzucato, E.; Vasseur, G.; Zito, M.; Bogomilov, M.; Tsenov, R.; Vankova-Kirilova, G.; Friend, M.; Hasegawa, T.; Nakadaira, T.; Sakashita, K.; Zambelli, L.; Autiero, D.; Caiulo, D.; Chaussard, L.; Déclais, Y.; Franco, D.; Marteau, J.; Pennacchio, E.; Bay, F.; Cantini, C.; Crivelli, P.; Epprecht, L.; Gendotti, A.; Di Luise, S.; Horikawa, S.; Murphy, S.; Nikolics, K.; Periale, L.; Regenfus, C.; Rubbia, A.; Sgalaberna, D.; Viant, T.; Wu, S.; Sergiampietri, F.; CERN. Geneva. SPS and PS Experiments Committee; SPSC

2014-01-01

In June 2012, an Expression of Interest for a long-baseline experiment (LBNO, CERN-SPSC-EOI-007) has been submitted to the CERN SPSC and is presently under review. LBNO considers three types of neutrino detector technologies: a double-phase liquid argon (LAr) TPC and a magnetised iron detector as far detectors. For the near detector, a high-pressure gas TPC embedded in a calorimeter and a magnet is the baseline design. A mandatory milestone in view of any future long baseline experiment is a concrete prototyping effort towards the envisioned large-scale detectors, and an accompanying campaign of measurements aimed at assessing the systematic errors that will be affecting their intended physics programme. Following an encouraging feedback from 108th SPSC on the technology choices, we have defined as priority the construction and operation of a $6\\times 6\\times 6$m$^3$ (active volume) double-phase liquid argon (DLAr) demonstrator, and a parallel development of the technologies necessary for large magnetised MIN...

Assessing large-scale wildlife responses to human infrastructure development.

Science.gov (United States)

Torres, Aurora; Jaeger, Jochen A G; Alonso, Juan Carlos

2016-07-26

Habitat loss and deterioration represent the main threats to wildlife species, and are closely linked to the expansion of roads and human settlements. Unfortunately, large-scale effects of these structures remain generally overlooked. Here, we analyzed the European transportation infrastructure network and found that 50% of the continent is within 1.5 km of transportation infrastructure. We present a method for assessing the impacts from infrastructure on wildlife, based on functional response curves describing density reductions in birds and mammals (e.g., road-effect zones), and apply it to Spain as a case study. The imprint of infrastructure extends over most of the country (55.5% in the case of birds and 97.9% for mammals), with moderate declines predicted for birds (22.6% of individuals) and severe declines predicted for mammals (46.6%). Despite certain limitations, we suggest the approach proposed is widely applicable to the evaluation of effects of planned infrastructure developments under multiple scenarios, and propose an internationally coordinated strategy to update and improve it in the future.

Failure Impact Assessment for Large-Scale Landslides Located Near Human Settlement: Case Study in Southern Taiwan

Directory of Open Access Journals (Sweden)

Ming-Chien Chung

2018-05-01

Full Text Available In 2009, Typhoon Morakot caused over 680 deaths and more than 20,000 landslides in Taiwan. From 2010 to 2015, the Central Geological Survey of the Ministry of Economic Affairs identified 1047 potential large-scale landslides in Taiwan, of which 103 may have affected human settlements. This paper presents an analytical procedure that can be applied to assess the possible impact of a landslide collapse on nearby settlements. In this paper, existing technologies, including interpretation of remote sensing images, hydrogeological investigation, and numerical analysis, are integrated to evaluate potential failure scenarios and the landslide scale of a specific case: the Xinzhuang landslide. GeoStudio and RAMMS analysis modes and hazard classification produced the following results: (1 evaluation of the failure mechanisms and the influence zones of large-scale landslides; (2 assessment of the migration and accumulation of the landslide mass after failure; and (3 a landslide hazard and evacuation map. The results of the case study show that this analytical procedure can quantitatively estimate potential threats to human settlements. Furthermore, it can be applied to other villages and used as a reference in disaster prevention and evacuation planning.

Accelerating Relevance Vector Machine for Large-Scale Data on Spark

Directory of Open Access Journals (Sweden)

Liu Fang

2017-01-01

Full Text Available Relevance vector machine (RVM is a machine learning algorithm based on a sparse Bayesian framework, which performs well when running classification and regression tasks on small-scale datasets. However, RVM also has certain drawbacks which restricts its practical applications such as (1 slow training process, (2 poor performance on training large-scale datasets. In order to solve these problem, we propose Discrete AdaBoost RVM (DAB-RVM which incorporate ensemble learning in RVM at first. This method performs well with large-scale low-dimensional datasets. However, as the number of features increases, the training time of DAB-RVM increases as well. To avoid this phenomenon, we utilize the sufficient training samples of large-scale datasets and propose all features boosting RVM (AFB-RVM, which modifies the way of obtaining weak classifiers. In our experiments we study the differences between various boosting techniques with RVM, demonstrating the performance of the proposed approaches on Spark. As a result of this paper, two proposed approaches on Spark for different types of large-scale datasets are available.

Open TG-GATEs: a large-scale toxicogenomics database

Science.gov (United States)

Igarashi, Yoshinobu; Nakatsu, Noriyuki; Yamashita, Tomoya; Ono, Atsushi; Ohno, Yasuo; Urushidani, Tetsuro; Yamada, Hiroshi

2015-01-01

Toxicogenomics focuses on assessing the safety of compounds using gene expression profiles. Gene expression signatures from large toxicogenomics databases are expected to perform better than small databases in identifying biomarkers for the prediction and evaluation of drug safety based on a compound's toxicological mechanisms in animal target organs. Over the past 10 years, the Japanese Toxicogenomics Project consortium (TGP) has been developing a large-scale toxicogenomics database consisting of data from 170 compounds (mostly drugs) with the aim of improving and enhancing drug safety assessment. Most of the data generated by the project (e.g. gene expression, pathology, lot number) are freely available to the public via Open TG-GATEs (Toxicogenomics Project-Genomics Assisted Toxicity Evaluation System). Here, we provide a comprehensive overview of the database, including both gene expression data and metadata, with a description of experimental conditions and procedures used to generate the database. Open TG-GATEs is available from http://toxico.nibio.go.jp/english/index.html. PMID:25313160

Assessment of disturbance at three spatial scales in two large tropical reservoirs

Directory of Open Access Journals (Sweden)

Letícia de Morais

2016-12-01

Full Text Available Large reservoirs are an increasingly common feature across tropical landscapes because of their importance for water supply, flood control and hydropower, but their ecological conditions are infrequently evaluated. Our objective was to assess the range of disturbances for two large tropical reservoirs and their influences on benthic macroinvertebrates. We tested three hypotheses: i a wide variation in the level of environmental disturbance can be observed among sites in the reservoirs; ii the two reservoirs would exhibit a different degree of disturbance level; and iii the magnitude of disturbance would influence the structure and composition of benthic assemblages. For each reservoir, we assessed land use (macroscale, physical habitat structure (mesoscale, and water quality (microscale. We sampled 40 sites in the littoral zones of both Três Marias and São Simão Reservoirs (Minas Gerais, Brazil. At the macroscale, we measured cover percentages of land use categories in buffer areas at each site, where each buffer was a circular arc of 250 m. At the mesoscale, we assessed the presence of human disturbances in the riparian and drawdown zones at the local (site scale. At the microscale, we assessed water quality at each macroinvertebrate sampling station using the Micro Disturbance Index (MDI. To evaluate anthropogenic disturbance of each site, we calculated an integrated disturbance index (IDI from a buffer disturbance index (BDI and a local disturbance index (LDI. For each site, we calculated richness and abundance of benthic macroinvertebrates, Chironomidae genera richness, abundance and percent Chironomidae individuals, abundance and percent EPT individuals, richness and percent EPT taxa, abundance and percent resistant individuals, and abundance and percent non-native individuals. We also evaluated the influence of disturbance on benthic macroinvertebrate assemblages at the entire-reservoir scale. The BDI, LDI and IDI had significantly

The Contribution of International Large-Scale Assessments to Educational Research: Combining Individual and Institutional Data Sources

Science.gov (United States)

Strietholt, Rolf; Scherer, Ronny

2018-01-01

The present paper aims to discuss how data from international large-scale assessments (ILSAs) can be utilized and combined, even with other existing data sources, in order to monitor educational outcomes and study the effectiveness of educational systems. We consider different purposes of linking data, namely, extending outcomes measures,…

Scale interactions in a mixing layer – the role of the large-scale gradients

KAUST Repository

Fiscaletti, D.

2016-02-15

© 2016 Cambridge University Press. The interaction between the large and the small scales of turbulence is investigated in a mixing layer, at a Reynolds number based on the Taylor microscale of , via direct numerical simulations. The analysis is performed in physical space, and the local vorticity root-mean-square (r.m.s.) is taken as a measure of the small-scale activity. It is found that positive large-scale velocity fluctuations correspond to large vorticity r.m.s. on the low-speed side of the mixing layer, whereas, they correspond to low vorticity r.m.s. on the high-speed side. The relationship between large and small scales thus depends on position if the vorticity r.m.s. is correlated with the large-scale velocity fluctuations. On the contrary, the correlation coefficient is nearly constant throughout the mixing layer and close to unity if the vorticity r.m.s. is correlated with the large-scale velocity gradients. Therefore, the small-scale activity appears closely related to large-scale gradients, while the correlation between the small-scale activity and the large-scale velocity fluctuations is shown to reflect a property of the large scales. Furthermore, the vorticity from unfiltered (small scales) and from low pass filtered (large scales) velocity fields tend to be aligned when examined within vortical tubes. These results provide evidence for the so-called \\'scale invariance\\' (Meneveau & Katz, Annu. Rev. Fluid Mech., vol. 32, 2000, pp. 1-32), and suggest that some of the large-scale characteristics are not lost at the small scales, at least at the Reynolds number achieved in the present simulation.

Coverage of the migrant population in large-scale assessment surveys. Experiences from PIAAC in Germany

Directory of Open Access Journals (Sweden)

Débora B. Maehler

2017-03-01

Full Text Available Abstract Background European countries, and especially Germany, are currently very much affected by human migration flows, with the result that the task of integration has become a challenge. Only very little empirical evidence on topics such as labor market participation and processes of social integration of migrant subpopulations is available to date from large-scale population surveys. The present paper provides an overview of the representation of the migrant population in the German Programme for the International Assessment of Adult Competencies (PIAAC sample and evaluates reasons for the under-coverage of this population. Methods We examine outcome rates and reasons for nonresponse among the migrant population based on sampling frame data, and we also examine para data from the interviewers’ contact protocols to evaluate time patterns for the successful contacting of migrants. Results and Conclusions This is the first time that results of this kind have been presented for a large-scale assessment in educational research. These results are also discussed in the context of future PIAAC cycles. Overall, they confirm the expectations in the literature that factors such as language problems result in lower contact and response rates among migrants.

Google Street View as an alternative method to car surveys in large-scale vegetation assessments.

Science.gov (United States)

Deus, Ernesto; Silva, Joaquim S; Catry, Filipe X; Rocha, Miguel; Moreira, Francisco

2015-10-01

Car surveys (CS) are a common method for assessing the distribution of alien invasive plants. Google Street View (GSV), a free-access web technology where users may experience a virtual travel along roads, has been suggested as a cost-effective alternative to car surveys. We tested if we could replicate the results from a countrywide survey conducted by car in Portugal using GSV as a remote sensing tool, aiming at assessing the distribution of Eucalyptus globulus Labill. wildlings on roadsides adjacent to eucalypt stands. Georeferenced points gathered along CS were used to create road transects visible as lines overlapping the road in GSV environment, allowing surveying the same sampling areas using both methods. This paper presents the results of the comparison between the two methods. Both methods produced similar models of plant abundance, selecting the same explanatory variables, in the same hierarchical order of importance and depicting a similar influence on plant abundance. Even though the GSV model had a lower performance and the GSV survey detected fewer plants, additional variables collected exclusively with GSV improved model performance and provided a new insight into additional factors influencing plant abundance. The survey using GSV required ca. 9 % of the funds and 62 % of the time needed to accomplish the CS. We conclude that GSV may be a cost-effective alternative to CS. We discuss some advantages and limitations of GSV as a survey method. We forecast that GSV may become a widespread tool in road ecology, particularly in large-scale vegetation assessments.

Age-related differences in the relations between individualised HRM and organisational performance: a large-scale employer survey

NARCIS (Netherlands)

Bal, P.M.; Dorenbosch, L.

2015-01-01

The current study aimed to investigate the relationship between individualised HRM practices and several measures of organisational performance, including the moderating role of employee age in these relationships. A large-scale representative study among 4,591 organisations in the Netherlands

Performance assessment of cogeneration and trigeneration systems for small scale applications

International Nuclear Information System (INIS)

Angrisani, Giovanni; Akisawa, Atsushi; Marrasso, Elisa; Roselli, Carlo; Sasso, Maurizio

2016-01-01

Highlights: • Indices and methods to assess the performance of polygeneration systems. • Index to evaluate the economic feasibility of trigeneration system is introduced. • Thermo-economic analysis is performed considering three commercial cogenerators. • Sensitivity analysis varying reference electric efficiency for European Countries. • Sensitivity analysis varying environmental and economic parameters. - Abstract: Cogeneration and trigeneration systems can contribute to the reduction of primary energy consumption and greenhouse gas emissions in residential and tertiary sectors, by reducing fossil fuels demand and grid losses with respect to conventional systems. To evaluate the performance of these systems, several indices and assessment methodologies can be used, due to the high complexity of such systems, which can consist of several energy conversion devices and can perform bidirectional interactions with external electric and thermal grids. In this paper, a review of the available indices and methodologies to assess the performances of polygeneration systems is provided. An index (TSS_t_r_i) aimed to assess the economic feasibility of a trigeneration system is also introduced and discussed. This activity started in the framework of the International Energy Agency Annex 54 project (“Integration of Micro-Generation and Related Energy Technologies in Buildings”), where research groups shared their expertise about methods applied in each Country to evaluate the performance of polygeneration systems. It was concluded that a thermo-economic analysis comparing the performance of a polygeneration system with those of a reference benchmark scenario, is a very suitable assessment method. Some of the reviewed methodologies are then applied to small scale commercial cogenerators. The sensitivity analysis is performed considering different reference average values of electric efficiency, unitary natural gas and electricity prices, and emission factors for

International Large-Scale Assessment Studies and Educational Policy-Making in Chile: Contexts and Dimensions of Influence

Science.gov (United States)

Cox, Cristián; Meckes, Lorena

2016-01-01

Since the 1990s, Chile has participated in all major international large-scale assessment studies (ILSAs) of the IEA and OECD, as well as the regional ones conducted by UNESCO in Latin America, after it had been involved in the very first international Science Study in 1970-1971. This article examines the various ways in which these studies have…

High performance nanostructured Silicon heterojunction for water splitting on large scales

KAUST Repository

Bonifazi, Marcella

2017-11-02

In past years the global demand for energy has been increasing steeply, as well as the awareness that new sources of clean energy are essential. Photo-electrochemical devices (PEC) for water splitting applications have stirred great interest, and different approach has been explored to improve the efficiency of these devices and to avoid optical losses at the interfaces with water. These include engineering materials and nanostructuring the device\\'s surfaces [1]-[2]. Despite the promising initial results, there are still many drawbacks that needs to be overcome to reach large scale production with optimized performances [3]. We present a new device that relies on the optimization of the nanostructuring process that exploits suitably disordered surfaces. Additionally, this device could harvest light on both sides to efficiently gain and store the energy to keep the photocatalytic reaction active.

High performance nanostructured Silicon heterojunction for water splitting on large scales

KAUST Repository

Bonifazi, Marcella; Fu, Hui-chun; He, Jr-Hau; Fratalocchi, Andrea

2017-01-01

In past years the global demand for energy has been increasing steeply, as well as the awareness that new sources of clean energy are essential. Photo-electrochemical devices (PEC) for water splitting applications have stirred great interest, and different approach has been explored to improve the efficiency of these devices and to avoid optical losses at the interfaces with water. These include engineering materials and nanostructuring the device's surfaces [1]-[2]. Despite the promising initial results, there are still many drawbacks that needs to be overcome to reach large scale production with optimized performances [3]. We present a new device that relies on the optimization of the nanostructuring process that exploits suitably disordered surfaces. Additionally, this device could harvest light on both sides to efficiently gain and store the energy to keep the photocatalytic reaction active.

Standard Errors for National Trends in International Large-Scale Assessments in the Case of Cross-National Differential Item Functioning

Science.gov (United States)

Sachse, Karoline A.; Haag, Nicole

2017-01-01

Standard errors computed according to the operational practices of international large-scale assessment studies such as the Programme for International Student Assessment's (PISA) or the Trends in International Mathematics and Science Study (TIMSS) may be biased when cross-national differential item functioning (DIF) and item parameter drift are…

Large-scale assessment of benthic communities across multiple marine protected areas using an autonomous underwater vehicle.

Science.gov (United States)

Ferrari, Renata; Marzinelli, Ezequiel M; Ayroza, Camila Rezende; Jordan, Alan; Figueira, Will F; Byrne, Maria; Malcolm, Hamish A; Williams, Stefan B; Steinberg, Peter D

2018-01-01

Marine protected areas (MPAs) are designed to reduce threats to biodiversity and ecosystem functioning from anthropogenic activities. Assessment of MPAs effectiveness requires synchronous sampling of protected and non-protected areas at multiple spatial and temporal scales. We used an autonomous underwater vehicle to map benthic communities in replicate 'no-take' and 'general-use' (fishing allowed) zones within three MPAs along 7o of latitude. We recorded 92 taxa and 38 morpho-groups across three large MPAs. We found that important habitat-forming biota (e.g. massive sponges) were more prevalent and abundant in no-take zones, while short ephemeral algae were more abundant in general-use zones, suggesting potential short-term effects of zoning (5-10 years). Yet, short-term effects of zoning were not detected at the community level (community structure or composition), while community structure varied significantly among MPAs. We conclude that by allowing rapid, simultaneous assessments at multiple spatial scales, autonomous underwater vehicles are useful to document changes in marine communities and identify adequate scales to manage them. This study advanced knowledge of marine benthic communities and their conservation in three ways. First, we quantified benthic biodiversity and abundance, generating the first baseline of these benthic communities against which the effectiveness of three large MPAs can be assessed. Second, we identified the taxonomic resolution necessary to assess both short and long-term effects of MPAs, concluding that coarse taxonomic resolution is sufficient given that analyses of community structure at different taxonomic levels were generally consistent. Yet, observed differences were taxa-specific and may have not been evident using our broader taxonomic classifications, a classification of mid to high taxonomic resolution may be necessary to determine zoning effects on key taxa. Third, we provide an example of statistical analyses and

The Phoenix series large scale LNG pool fire experiments.

Energy Technology Data Exchange (ETDEWEB)

Simpson, Richard B.; Jensen, Richard Pearson; Demosthenous, Byron; Luketa, Anay Josephine; Ricks, Allen Joseph; Hightower, Marion Michael; Blanchat, Thomas K.; Helmick, Paul H.; Tieszen, Sheldon Robert; Deola, Regina Anne; Mercier, Jeffrey Alan; Suo-Anttila, Jill Marie; Miller, Timothy J.

2010-12-01

The increasing demand for natural gas could increase the number and frequency of Liquefied Natural Gas (LNG) tanker deliveries to ports across the United States. Because of the increasing number of shipments and the number of possible new facilities, concerns about the potential safety of the public and property from an accidental, and even more importantly intentional spills, have increased. While improvements have been made over the past decade in assessing hazards from LNG spills, the existing experimental data is much smaller in size and scale than many postulated large accidental and intentional spills. Since the physics and hazards from a fire change with fire size, there are concerns about the adequacy of current hazard prediction techniques for large LNG spills and fires. To address these concerns, Congress funded the Department of Energy (DOE) in 2008 to conduct a series of laboratory and large-scale LNG pool fire experiments at Sandia National Laboratories (Sandia) in Albuquerque, New Mexico. This report presents the test data and results of both sets of fire experiments. A series of five reduced-scale (gas burner) tests (yielding 27 sets of data) were conducted in 2007 and 2008 at Sandia's Thermal Test Complex (TTC) to assess flame height to fire diameter ratios as a function of nondimensional heat release rates for extrapolation to large-scale LNG fires. The large-scale LNG pool fire experiments were conducted in a 120 m diameter pond specially designed and constructed in Sandia's Area III large-scale test complex. Two fire tests of LNG spills of 21 and 81 m in diameter were conducted in 2009 to improve the understanding of flame height, smoke production, and burn rate and therefore the physics and hazards of large LNG spills and fires.

Large-scale preparation of hollow graphitic carbon nanospheres

International Nuclear Information System (INIS)

Feng, Jun; Li, Fu; Bai, Yu-Jun; Han, Fu-Dong; Qi, Yong-Xin; Lun, Ning; Lu, Xi-Feng

2013-01-01

Hollow graphitic carbon nanospheres (HGCNSs) were synthesized on large scale by a simple reaction between glucose and Mg at 550 °C in an autoclave. Characterization by X-ray diffraction, Raman spectroscopy and transmission electron microscopy demonstrates the formation of HGCNSs with an average diameter of 10 nm or so and a wall thickness of a few graphenes. The HGCNSs exhibit a reversible capacity of 391 mAh g −1 after 60 cycles when used as anode materials for Li-ion batteries. -- Graphical abstract: Hollow graphitic carbon nanospheres could be prepared on large scale by the simple reaction between glucose and Mg at 550 °C, which exhibit superior electrochemical performance to graphite. Highlights: ► Hollow graphitic carbon nanospheres (HGCNSs) were prepared on large scale at 550 °C ► The preparation is simple, effective and eco-friendly. ► The in situ yielded MgO nanocrystals promote the graphitization. ► The HGCNSs exhibit superior electrochemical performance to graphite.

A Mountain-Scale Monitoring Network for Yucca Mountain Performance Confirmation

International Nuclear Information System (INIS)

Freifeld, Barry; Tsang, Yvonne

2006-01-01

Confirmation of the performance of Yucca Mountain is required by 10 CFR Part 63.131 to indicate, where practicable, that the natural system acts as a barrier, as intended. Hence, performance confirmation monitoring and testing would provide data for continued assessment during the pre-closure period. In general, to carry out testing at a relevant scale is always important, and in the case of performance confirmation, it is particularly important to be able to test at the scale of the repository. We view the large perturbation caused by construction of the repository at Yucca Mountain as a unique opportunity to study the large-scale behavior of the natural barrier system. Repository construction would necessarily introduce traced fluids and result in the creation of leachates. A program to monitor traced fluids and construction leachates permits evaluation of transport through the unsaturated zone and potentially downgradient through the saturated zone. A robust sampling and monitoring network for continuous measurement of important parameters, and for periodic collection of agrochemical samples, is proposed to observe thermo-hydrogeochemical changes near the repository horizon and down to the water table. The sampling and monitoring network can be used to provide data to (1) assess subsurface conditions encountered and changes in those conditions during construction and waste emplacement operations; and (2) for modeling to determine that the natural system is functioning as intended

Prototype Vector Machine for Large Scale Semi-Supervised Learning

Energy Technology Data Exchange (ETDEWEB)

Zhang, Kai; Kwok, James T.; Parvin, Bahram

2009-04-29

Practicaldataminingrarelyfalls exactlyinto the supervisedlearning scenario. Rather, the growing amount of unlabeled data poses a big challenge to large-scale semi-supervised learning (SSL). We note that the computationalintensivenessofgraph-based SSLarises largely from the manifold or graph regularization, which in turn lead to large models that are dificult to handle. To alleviate this, we proposed the prototype vector machine (PVM), a highlyscalable,graph-based algorithm for large-scale SSL. Our key innovation is the use of"prototypes vectors" for effcient approximation on both the graph-based regularizer and model representation. The choice of prototypes are grounded upon two important criteria: they not only perform effective low-rank approximation of the kernel matrix, but also span a model suffering the minimum information loss compared with the complete model. We demonstrate encouraging performance and appealing scaling properties of the PVM on a number of machine learning benchmark data sets.

Large-scale dynamic compaction of natural salt

International Nuclear Information System (INIS)

Hansen, F.D.; Ahrens, E.H.

1996-01-01

A large-scale dynamic compaction demonstration of natural salt was successfully completed. About 40 m 3 of salt were compacted in three, 2-m lifts by dropping a 9,000-kg weight from a height of 15 m in a systematic pattern to achieve desired compaction energy. To enhance compaction, 1 wt% water was added to the relatively dry mine-run salt. The average compacted mass fractional density was 0.90 of natural intact salt, and in situ nitrogen permeabilities averaged 9X10 -14 m 2 . This established viability of dynamic compacting for placing salt shaft seal components. The demonstration also provided compacted salt parameters needed for shaft seal system design and performance assessments of the Waste Isolation Pilot Plant

Assessment of clean development mechanism potential of large-scale energy efficiency measures in heavy industries

International Nuclear Information System (INIS)

Hayashi, Daisuke; Krey, Matthias

2007-01-01

This paper assesses clean development mechanism (CDM) potential of large-scale energy efficiency measures in selected heavy industries (iron and steel, cement, aluminium, pulp and paper, and ammonia) taking India and Brazil as examples of CDM project host countries. We have chosen two criteria for identification of the CDM potential of each energy efficiency measure: (i) emission reductions volume (in CO 2 e) that can be expected from the measure and (ii) likelihood of the measure passing the additionality test of the CDM Executive Board (EB) when submitted as a proposed CDM project activity. The paper shows that the CDM potential of large-scale energy efficiency measures strongly depends on the project-specific and country-specific context. In particular, technologies for the iron and steel industry (coke dry quenching (CDQ), top pressure recovery turbine (TRT), and basic oxygen furnace (BOF) gas recovery), the aluminium industry (point feeder prebake (PFPB) smelter), and the pulp and paper industry (continuous digester technology) offer promising CDM potential

Study on sandstorm PM10 exposure assessment in the large-scale region: a case study in Inner Mongolia.

Science.gov (United States)

Wang, Hongmei; Lv, Shihai; Diao, Zhaoyan; Wang, Baolu; Zhang, Han; Yu, Caihong

2018-04-12

The current exposure-effect curves describing sandstorm PM 10 exposure and the health effects are drawn roughly by the outdoor concentration (OC), which ignored the exposure levels of people's practical activity sites. The main objective of this work is to develop a novel approach to quantify human PM 10 exposure by their socio-categorized micro-environment activities-time weighed (SCMEATW) in strong sandstorm period, which can be used to assess the exposure profiles in the large-scale region. Types of people's SCMEATW were obtained by questionnaire investigation. Different types of representatives were trackly recorded during the big sandstorm. The average exposure levels were estimated by SCMEATW. Furthermore, the geographic information system (GIS) technique was taken not only to simulate the outdoor concentration spatially but also to create human exposure outlines in a visualized map simultaneously, which could help to understand the risk to different types of people. Additionally, exposure-response curves describing the acute outpatient rate odds by sandstorm were formed by SCMEATW, and the differences between SCMEATW and OC were compared. Results indicated that acute outpatient rate odds had relationships with PM 10 exposure from SCMEATW, with a level less than that of OC. Some types of people, such as herdsmen and those people walking outdoors during a strong sandstorm, have more risk than office men. Our findings provide more understanding of human practical activities on their exposure levels; they especially provide a tool to understand sandstorm PM 10 exposure in large scale spatially, which might help to perform the different categories population's risk assessment regionally.

Performance/price estimates for cortex-scale hardware: a design space exploration.

Science.gov (United States)

Zaveri, Mazad S; Hammerstrom, Dan

2011-04-01

In this paper, we revisit the concept of virtualization. Virtualization is useful for understanding and investigating the performance/price and other trade-offs related to the hardware design space. Moreover, it is perhaps the most important aspect of a hardware design space exploration. Such a design space exploration is a necessary part of the study of hardware architectures for large-scale computational models for intelligent computing, including AI, Bayesian, bio-inspired and neural models. A methodical exploration is needed to identify potentially interesting regions in the design space, and to assess the relative performance/price points of these implementations. As an example, in this paper we investigate the performance/price of (digital and mixed-signal) CMOS and hypothetical CMOL (nanogrid) technology based hardware implementations of human cortex-scale spiking neural systems. Through this analysis, and the resulting performance/price points, we demonstrate, in general, the importance of virtualization, and of doing these kinds of design space explorations. The specific results suggest that hybrid nanotechnology such as CMOL is a promising candidate to implement very large-scale spiking neural systems, providing a more efficient utilization of the density and storage benefits of emerging nano-scale technologies. In general, we believe that the study of such hypothetical designs/architectures will guide the neuromorphic hardware community towards building large-scale systems, and help guide research trends in intelligent computing, and computer engineering. Copyright © 2010 Elsevier Ltd. All rights reserved.

Zone modelling of the thermal performances of a large-scale bloom reheating furnace

International Nuclear Information System (INIS)

Tan, Chee-Keong; Jenkins, Joana; Ward, John; Broughton, Jonathan; Heeley, Andy

2013-01-01

This paper describes the development and comparison of a two- (2D) and three-dimensional (3D) mathematical models, based on the zone method of radiation analysis, to simulate the thermal performances of a large bloom reheating furnace. The modelling approach adopted in the current paper differs from previous work since it takes into account the net radiation interchanges between the top and bottom firing sections of the furnace and also allows for enthalpy exchange due to the flows of combustion products between these sections. The models were initially validated at two different furnace throughput rates using experimental and plant's model data supplied by Tata Steel. The results to-date demonstrated that the model predictions are in good agreement with measured heating profiles of the blooms encountered in the actual furnace. It was also found no significant differences between the predictions from the 2D and 3D models. Following the validation, the 2D model was then used to assess the impact of the furnace responses to changing throughput rate. It was found that the potential furnace response to changing throughput rate influences the settling time of the furnace to the next steady state operation. Overall the current work demonstrates the feasibility and practicality of zone modelling and its potential for incorporation into a model based furnace control system. - Highlights: ► 2D and 3D zone models of large-scale bloom reheating furnace. ► The models were validated with experimental and plant model data. ► Examine the transient furnace response to changing the furnace throughput rates. ► No significant differences found between the predictions from the 2D and 3D models.

Economically viable large-scale hydrogen liquefaction

Science.gov (United States)

Cardella, U.; Decker, L.; Klein, H.

2017-02-01

The liquid hydrogen demand, particularly driven by clean energy applications, will rise in the near future. As industrial large scale liquefiers will play a major role within the hydrogen supply chain, production capacity will have to increase by a multiple of today’s typical sizes. The main goal is to reduce the total cost of ownership for these plants by increasing energy efficiency with innovative and simple process designs, optimized in capital expenditure. New concepts must ensure a manageable plant complexity and flexible operability. In the phase of process development and selection, a dimensioning of key equipment for large scale liquefiers, such as turbines and compressors as well as heat exchangers, must be performed iteratively to ensure technological feasibility and maturity. Further critical aspects related to hydrogen liquefaction, e.g. fluid properties, ortho-para hydrogen conversion, and coldbox configuration, must be analysed in detail. This paper provides an overview on the approach, challenges and preliminary results in the development of efficient as well as economically viable concepts for large-scale hydrogen liquefaction.

Assessment of climate change impacts on rainfall using large scale ...

Indian Academy of Sciences (India)

Many of the applied techniques in water resources management can be directly or indirectly influenced by ... is based on large scale climate signals data around the world. In order ... predictand relationships are often very complex. .... constraints to solve the optimization problem. ..... social, and environmental sustainability.

A Diagnostic Comparison of Turkish and Korean Students’ Mathematics Performances on the TIMSS 2011 Assessment

Directory of Open Access Journals (Sweden)

Sedat Şen

2015-11-01

Full Text Available The purpose of the present study was to analyze an international large-scale data set using a cognitive assessment approach. Although some researchers question the usefulness of international large-scale assessments (e.g., TIMSS, participating countries have continued to use the results from these large-scale assessments to improve their curricula and teaching methods. Despite the common reporting practice—single-score—in these large scale assessments gives useful insights about students’ overall performances, they still lack diagnostic information. Cognitive diagnosis models (CDMs were developed to provide more feedback on students’ cognitive strengths and weaknesses. This study retrofitted the TIMSS 2011 eighth grade mathematics assessment by applying a specific CDM called the DINA (the deterministic, inputs, noisy, “and” gate model to data from South Korea and Turkey. Results of the DINA model were used to make a detailed comparison between students of these two countries.

Energy transfers in large-scale and small-scale dynamos

Science.gov (United States)

Samtaney, Ravi; Kumar, Rohit; Verma, Mahendra

2015-11-01

We present the energy transfers, mainly energy fluxes and shell-to-shell energy transfers in small-scale dynamo (SSD) and large-scale dynamo (LSD) using numerical simulations of MHD turbulence for Pm = 20 (SSD) and for Pm = 0.2 on 10243 grid. For SSD, we demonstrate that the magnetic energy growth is caused by nonlocal energy transfers from the large-scale or forcing-scale velocity field to small-scale magnetic field. The peak of these energy transfers move towards lower wavenumbers as dynamo evolves, which is the reason for the growth of the magnetic fields at the large scales. The energy transfers U2U (velocity to velocity) and B2B (magnetic to magnetic) are forward and local. For LSD, we show that the magnetic energy growth takes place via energy transfers from large-scale velocity field to large-scale magnetic field. We observe forward U2U and B2B energy flux, similar to SSD.

Fault Transient Analysis and Protection Performance Evaluation within a Large-scale PV Power Plant

Directory of Open Access Journals (Sweden)

Wen Jinghua

2016-01-01

Full Text Available In this paper, a short-circuit test within a large-scale PV power plant with a total capacity of 850MWp is discussed. The fault currents supplied by the PV generation units are presented and analysed. According to the fault behaviour, the existing protection coordination principles with the plant are considered and their performances are evaluated. Moreover, these protections are examined in simulation platform under different operating situations. A simple measure with communication system is proposed to deal with the foreseeable problem about the current protection scheme in the PV power plant.

A large scale field experiment in the Amazon basin (LAMBADA/BATERISTA)

NARCIS (Netherlands)

Dolman, A.J.; Kabat, P.; Gash, J.H.C.; Noilhan, J.; Jochum, A.M.; Nobre, C.

1995-01-01

A description is given of a large-scale field experiment planned in the Amazon basin, aimed at assessing the large-scale balances of energy, water and carbon dioxide. The embedding of this experiment in global change programmes is described, viz. the Biospheric Aspects of the Hydrological Cycle

A Hybrid Testbed for Performance Evaluation of Large-Scale Datacenter Networks

DEFF Research Database (Denmark)

Pilimon, Artur; Ruepp, Sarah Renée

2018-01-01

Datacenters (DC) as well as their network interconnects are growing in scale and complexity. They are constantly being challenged in terms of energy and resource utilization efficiency, scalability, availability, reliability and performance requirements. Therefore, these resource-intensive enviro......Datacenters (DC) as well as their network interconnects are growing in scale and complexity. They are constantly being challenged in terms of energy and resource utilization efficiency, scalability, availability, reliability and performance requirements. Therefore, these resource......-intensive environments must be properly tested and analyzed in order to make timely upgrades and transformations. However, a limited number of academic institutions and Research and Development companies have access to production scale DC Network (DCN) testing facilities, and resource-limited studies can produce...... misleading or inaccurate results. To address this problem, we introduce an alternative solution, which forms a solid base for a more realistic and comprehensive performance evaluation of different aspects of DCNs. It is based on the System-in-the-loop (SITL) concept, where real commercial DCN equipment...

Evaluation of creep-fatigue crack growth for large-scale FBR reactor vessel and NDE assessment

Energy Technology Data Exchange (ETDEWEB)

Joo, Young Sang; Kim, Jong Bum; Kim, Seok Hun; Yoo, Bong

2001-03-01

Creep fatigue crack growth contributes to the failure of FRB reactor vessels in high temperature condition. In the design stage of reactor vessel, crack growth evaluation is very important to ensure the structural safety and setup the in-service inspection strategy. In this study, creep-fatigue crack growth evaluation has been performed for the semi-elliptical surface cracks subjected to thermal loading. The thermal stress analysis of a large-scale FBR reactor vessel has been carried out for the load conditions. The distributions of axial, radial, hoop, and Von Mises stresses were obtained for the loading conditions. At the maximum point of the axial and hoop stress, the longitudinal and circumferential surface cracks (i.e. PTS crack, NDE short crack and shallow long crack) were postulated. Using the maximum and minimum values of stresses, the creep-fatigue crack growth of the proposed cracks was simulated. The crack growth rate of circumferential cracks becomes greater than that of longitudinal cracks. The total crack growth of the largest PTS crack is very small after 427 cycles. The structural integrity of a large-scale reactor can be maintained for the plant life. The crack depth growth of the shallow long crack is faster than that of the NDE short crack. In the ISI of the large-scale FBR reactor vessel, the ultrasonic inspection is beneficial to detect the shallow circumferential cracks.

Needs, opportunities, and options for large scale systems research

Energy Technology Data Exchange (ETDEWEB)

Thompson, G.L.

1984-10-01

The Office of Energy Research was recently asked to perform a study of Large Scale Systems in order to facilitate the development of a true large systems theory. It was decided to ask experts in the fields of electrical engineering, chemical engineering and manufacturing/operations research for their ideas concerning large scale systems research. The author was asked to distribute a questionnaire among these experts to find out their opinions concerning recent accomplishments and future research directions in large scale systems research. He was also requested to convene a conference which included three experts in each area as panel members to discuss the general area of large scale systems research. The conference was held on March 26--27, 1984 in Pittsburgh with nine panel members, and 15 other attendees. The present report is a summary of the ideas presented and the recommendations proposed by the attendees.

Large-scale preparation of hollow graphitic carbon nanospheres

Energy Technology Data Exchange (ETDEWEB)

Feng, Jun; Li, Fu [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Bai, Yu-Jun, E-mail: byj97@126.com [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); State Key laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Han, Fu-Dong; Qi, Yong-Xin; Lun, Ning [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Lu, Xi-Feng [Lunan Institute of Coal Chemical Engineering, Jining 272000 (China)

2013-01-15

Hollow graphitic carbon nanospheres (HGCNSs) were synthesized on large scale by a simple reaction between glucose and Mg at 550 Degree-Sign C in an autoclave. Characterization by X-ray diffraction, Raman spectroscopy and transmission electron microscopy demonstrates the formation of HGCNSs with an average diameter of 10 nm or so and a wall thickness of a few graphenes. The HGCNSs exhibit a reversible capacity of 391 mAh g{sup -1} after 60 cycles when used as anode materials for Li-ion batteries. -- Graphical abstract: Hollow graphitic carbon nanospheres could be prepared on large scale by the simple reaction between glucose and Mg at 550 Degree-Sign C, which exhibit superior electrochemical performance to graphite. Highlights: Black-Right-Pointing-Pointer Hollow graphitic carbon nanospheres (HGCNSs) were prepared on large scale at 550 Degree-Sign C Black-Right-Pointing-Pointer The preparation is simple, effective and eco-friendly. Black-Right-Pointing-Pointer The in situ yielded MgO nanocrystals promote the graphitization. Black-Right-Pointing-Pointer The HGCNSs exhibit superior electrochemical performance to graphite.

Optical interconnect for large-scale systems

Science.gov (United States)

Dress, William

2013-02-01

This paper presents a switchless, optical interconnect module that serves as a node in a network of identical distribution modules for large-scale systems. Thousands to millions of hosts or endpoints may be interconnected by a network of such modules, avoiding the need for multi-level switches. Several common network topologies are reviewed and their scaling properties assessed. The concept of message-flow routing is discussed in conjunction with the unique properties enabled by the optical distribution module where it is shown how top-down software control (global routing tables, spanning-tree algorithms) may be avoided.

Prehospital Acute Stroke Severity Scale to Predict Large Artery Occlusion: Design and Comparison With Other Scales.

Science.gov (United States)

Hastrup, Sidsel; Damgaard, Dorte; Johnsen, Søren Paaske; Andersen, Grethe

2016-07-01

We designed and validated a simple prehospital stroke scale to identify emergent large vessel occlusion (ELVO) in patients with acute ischemic stroke and compared the scale to other published scales for prediction of ELVO. A national historical test cohort of 3127 patients with information on intracranial vessel status (angiography) before reperfusion therapy was identified. National Institutes of Health Stroke Scale (NIHSS) items with the highest predictive value of occlusion of a large intracranial artery were identified, and the most optimal combination meeting predefined criteria to ensure usefulness in the prehospital phase was determined. The predictive performance of Prehospital Acute Stroke Severity (PASS) scale was compared with other published scales for ELVO. The PASS scale was composed of 3 NIHSS scores: level of consciousness (month/age), gaze palsy/deviation, and arm weakness. In derivation of PASS 2/3 of the test cohort was used and showed accuracy (area under the curve) of 0.76 for detecting large arterial occlusion. Optimal cut point ≥2 abnormal scores showed: sensitivity=0.66 (95% CI, 0.62-0.69), specificity=0.83 (0.81-0.85), and area under the curve=0.74 (0.72-0.76). Validation on 1/3 of the test cohort showed similar performance. Patients with a large artery occlusion on angiography with PASS ≥2 had a median NIHSS score of 17 (interquartile range=6) as opposed to PASS <2 with a median NIHSS score of 6 (interquartile range=5). The PASS scale showed equal performance although more simple when compared with other scales predicting ELVO. The PASS scale is simple and has promising accuracy for prediction of ELVO in the field. © 2016 American Heart Association, Inc.

Exploring the large-scale structure of Taylor–Couette turbulence through Large-Eddy Simulations

Science.gov (United States)

Ostilla-Mónico, Rodolfo; Zhu, Xiaojue; Verzicco, Roberto

2018-04-01

Large eddy simulations (LES) of Taylor-Couette (TC) flow, the flow between two co-axial and independently rotating cylinders are performed in an attempt to explore the large-scale axially-pinned structures seen in experiments and simulations. Both static and dynamic LES models are used. The Reynolds number is kept fixed at Re = 3.4 · 104, and the radius ratio η = ri /ro is set to η = 0.909, limiting the effects of curvature and resulting in frictional Reynolds numbers of around Re τ ≈ 500. Four rotation ratios from Rot = ‑0.0909 to Rot = 0.3 are simulated. First, the LES of TC is benchmarked for different rotation ratios. Both the Smagorinsky model with a constant of cs = 0.1 and the dynamic model are found to produce reasonable results for no mean rotation and cyclonic rotation, but deviations increase for increasing rotation. This is attributed to the increasing anisotropic character of the fluctuations. Second, “over-damped” LES, i.e. LES with a large Smagorinsky constant is performed and is shown to reproduce some features of the large-scale structures, even when the near-wall region is not adequately modeled. This shows the potential for using over-damped LES for fast explorations of the parameter space where large-scale structures are found.

Transfrontier consequences to the population of Greece of large scale nuclear accidents: a preliminary assessment

International Nuclear Information System (INIS)

Kollas, J.G.; Catsaros, Nicolas.

1985-06-01

In this report the consequences to the population of Greece from hypothetical large scale nuclear accidents at the Kozlodui (Bulgaria) nuclear power station are estimated under some simplifying assumptions. Three different hypothetical accident scenarios - the most serious for pressurized water reactors - are examined. The analysis is performed by the current Greek version of code CRAC2 and includes health and economic consequences to the population of Greece. (author)

Sensitivity analysis for large-scale problems

Science.gov (United States)

Noor, Ahmed K.; Whitworth, Sandra L.

1987-01-01

The development of efficient techniques for calculating sensitivity derivatives is studied. The objective is to present a computational procedure for calculating sensitivity derivatives as part of performing structural reanalysis for large-scale problems. The scope is limited to framed type structures. Both linear static analysis and free-vibration eigenvalue problems are considered.

Meteorological impact assessment of possible large scale irrigation in Southwest Saudi Arabia

NARCIS (Netherlands)

Maat, ter H.W.; Hutjes, R.W.A.; Ohba, R.; Ueda, H.; Bisselink, B.; Bauer, T.

2006-01-01

On continental to regional scales feedbacks between landuse and landcover change and climate have been widely documented over the past 10¿15 years. In the present study we explore the possibility that also vegetation changes over much smaller areas may affect local precipitation regimes. Large scale

A large-scale peer teaching programme - acceptance and benefit.

Science.gov (United States)

Schuetz, Elisabeth; Obirei, Barbara; Salat, Daniela; Scholz, Julia; Hann, Dagmar; Dethleffsen, Kathrin

2017-08-01

performance in first assessments. 94% of the students participating in tutorials offered in the study year 2013/14 rated the tutorials as "excellent" or "good". An objective benefit has been shown by a significant increase in re-assessment scores with an effect size between the medium and large magnitudes for participants of tutorials compared to non-participants in the years 2012, 2013 and 2014. In addition, significantly higher pass rates of re-assessments could be observed. Acceptance, utilisation and benefit of the assessed peer teaching programme are high. Beyond the support of students, a contribution to the individualisation of studies and teaching is made. Further studies are necessary to investigate possible influences of large-scale peer teaching programmes, for example on the reduction of study length and drop-off rates, as well as additional effects on academic achievements. Copyright © 2017. Published by Elsevier GmbH.

An integrated model for assessing both crop productivity and agricultural water resources at a large scale

Science.gov (United States)

Okada, M.; Sakurai, G.; Iizumi, T.; Yokozawa, M.

2012-12-01

Agricultural production utilizes regional resources (e.g. river water and ground water) as well as local resources (e.g. temperature, rainfall, solar energy). Future climate changes and increasing demand due to population increases and economic developments would intensively affect the availability of water resources for agricultural production. While many studies assessed the impacts of climate change on agriculture, there are few studies that dynamically account for changes in water resources and crop production. This study proposes an integrated model for assessing both crop productivity and agricultural water resources at a large scale. Also, the irrigation management to subseasonal variability in weather and crop response varies for each region and each crop. To deal with such variations, we used the Markov Chain Monte Carlo technique to quantify regional-specific parameters associated with crop growth and irrigation water estimations. We coupled a large-scale crop model (Sakurai et al. 2012), with a global water resources model, H08 (Hanasaki et al. 2008). The integrated model was consisting of five sub-models for the following processes: land surface, crop growth, river routing, reservoir operation, and anthropogenic water withdrawal. The land surface sub-model was based on a watershed hydrology model, SWAT (Neitsch et al. 2009). Surface and subsurface runoffs simulated by the land surface sub-model were input to the river routing sub-model of the H08 model. A part of regional water resources available for agriculture, simulated by the H08 model, was input as irrigation water to the land surface sub-model. The timing and amount of irrigation water was simulated at a daily step. The integrated model reproduced the observed streamflow in an individual watershed. Additionally, the model accurately reproduced the trends and interannual variations of crop yields. To demonstrate the usefulness of the integrated model, we compared two types of impact assessment of

The Neglected Situation: Assessment Performance and Interaction in Context

Science.gov (United States)

Maddox, Bryan

2015-01-01

Informed by Goffman's influential essay on "The neglected situation" this paper examines the contextual and interactive dimensions of performance in large-scale educational assessments. The paper applies Goffman's participation framework and associated theory in linguistic anthropology to examine how testing situations are framed and…

Multilevel Latent Class Analysis for Large-Scale Educational Assessment Data: Exploring the Relation between the Curriculum and Students' Mathematical Strategies

Science.gov (United States)

Fagginger Auer, Marije F.; Hickendorff, Marian; Van Putten, Cornelis M.; Béguin, Anton A.; Heiser, Willem J.

2016-01-01

A first application of multilevel latent class analysis (MLCA) to educational large-scale assessment data is demonstrated. This statistical technique addresses several of the challenges that assessment data offers. Importantly, MLCA allows modeling of the often ignored teacher effects and of the joint influence of teacher and student variables.…

Large-scale data analytics

CERN Document Server

Gkoulalas-Divanis, Aris

2014-01-01

Provides cutting-edge research in large-scale data analytics from diverse scientific areas Surveys varied subject areas and reports on individual results of research in the field Shares many tips and insights into large-scale data analytics from authors and editors with long-term experience and specialization in the field

Real-time simulation of large-scale floods

Science.gov (United States)

Liu, Q.; Qin, Y.; Li, G. D.; Liu, Z.; Cheng, D. J.; Zhao, Y. H.

2016-08-01

According to the complex real-time water situation, the real-time simulation of large-scale floods is very important for flood prevention practice. Model robustness and running efficiency are two critical factors in successful real-time flood simulation. This paper proposed a robust, two-dimensional, shallow water model based on the unstructured Godunov- type finite volume method. A robust wet/dry front method is used to enhance the numerical stability. An adaptive method is proposed to improve the running efficiency. The proposed model is used for large-scale flood simulation on real topography. Results compared to those of MIKE21 show the strong performance of the proposed model.

Optimization of large-scale heterogeneous system-of-systems models.

Energy Technology Data Exchange (ETDEWEB)

Parekh, Ojas; Watson, Jean-Paul; Phillips, Cynthia Ann; Siirola, John; Swiler, Laura Painton; Hough, Patricia Diane (Sandia National Laboratories, Livermore, CA); Lee, Herbert K. H. (University of California, Santa Cruz, Santa Cruz, CA); Hart, William Eugene; Gray, Genetha Anne (Sandia National Laboratories, Livermore, CA); Woodruff, David L. (University of California, Davis, Davis, CA)

2012-01-01

Decision makers increasingly rely on large-scale computational models to simulate and analyze complex man-made systems. For example, computational models of national infrastructures are being used to inform government policy, assess economic and national security risks, evaluate infrastructure interdependencies, and plan for the growth and evolution of infrastructure capabilities. A major challenge for decision makers is the analysis of national-scale models that are composed of interacting systems: effective integration of system models is difficult, there are many parameters to analyze in these systems, and fundamental modeling uncertainties complicate analysis. This project is developing optimization methods to effectively represent and analyze large-scale heterogeneous system of systems (HSoS) models, which have emerged as a promising approach for describing such complex man-made systems. These optimization methods enable decision makers to predict future system behavior, manage system risk, assess tradeoffs between system criteria, and identify critical modeling uncertainties.

Large-scale grid management

International Nuclear Information System (INIS)

Langdal, Bjoern Inge; Eggen, Arnt Ove

2003-01-01

The network companies in the Norwegian electricity industry now have to establish a large-scale network management, a concept essentially characterized by (1) broader focus (Broad Band, Multi Utility,...) and (2) bigger units with large networks and more customers. Research done by SINTEF Energy Research shows so far that the approaches within large-scale network management may be structured according to three main challenges: centralization, decentralization and out sourcing. The article is part of a planned series

A feasibility assessment for incorporating of passive RHRS into large scale active PWR

Energy Technology Data Exchange (ETDEWEB)

Kim, S O; Sub, S Y; Kim, Y S; Chang, M H; Park, J K [Korea Atomic Energy Research Inst., Taejon (Korea, Republic of)

1996-12-01

A feasibility study was carried out for the possible incorporation of passive RHRS (Residual Heat Removal System) into a large-scale of active PWR plant. Four kinds of system configurations were considered. For each case its performance and impacts on plant safety, cost, licensing, operation and maintenance were evaluated. The evaluation came up with a finding of PRHRS with a gravity feed tank as most probable design concept. However, considering rearrangement of structure and pipe routing inside and outside containment, it is concluded that implementation of the PRHRS concept into well developed active plants is not desirable at present. (author). 6 refs, 7 figs, 1 tab.

A feasibility assessment for incorporating of passive RHRS into large scale active PWR

International Nuclear Information System (INIS)

Kim, S.O.; Sub, S.Y.; Kim, Y.S.; Chang, M.H.; Park, J.K.

1996-01-01

A feasibility study was carried out for the possible incorporation of passive RHRS (Residual Heat Removal System) into a large-scale of active PWR plant. Four kinds of system configurations were considered. For each case its performance and impacts on plant safety, cost, licensing, operation and maintenance were evaluated. The evaluation came up with a finding of PRHRS with a gravity feed tank as most probable design concept. However, considering rearrangement of structure and pipe routing inside and outside containment, it is concluded that implementation of the PRHRS concept into well developed active plants is not desirable at present. (author). 6 refs, 7 figs, 1 tab

A long-term, continuous simulation approach for large-scale flood risk assessments

Science.gov (United States)

Falter, Daniela; Schröter, Kai; Viet Dung, Nguyen; Vorogushyn, Sergiy; Hundecha, Yeshewatesfa; Kreibich, Heidi; Apel, Heiko; Merz, Bruno

2014-05-01

The Regional Flood Model (RFM) is a process based model cascade developed for flood risk assessments of large-scale basins. RFM consists of four model parts: the rainfall-runoff model SWIM, a 1D channel routing model, a 2D hinterland inundation model and the flood loss estimation model for residential buildings FLEMOps+r. The model cascade was recently undertaken a proof-of-concept study at the Elbe catchment (Germany) to demonstrate that flood risk assessments, based on a continuous simulation approach, including rainfall-runoff, hydrodynamic and damage estimation models, are feasible for large catchments. The results of this study indicated that uncertainties are significant, especially for hydrodynamic simulations. This was basically a consequence of low data quality and disregarding dike breaches. Therefore, RFM was applied with a refined hydraulic model setup for the Elbe tributary Mulde. The study area Mulde catchment comprises about 6,000 km2 and 380 river-km. The inclusion of more reliable information on overbank cross-sections and dikes considerably improved the results. For the application of RFM for flood risk assessments, long-term climate input data is needed to drive the model chain. This model input was provided by a multi-site, multi-variate weather generator that produces sets of synthetic meteorological data reproducing the current climate statistics. The data set comprises 100 realizations of 100 years of meteorological data. With the proposed continuous simulation approach of RFM, we simulated a virtual period of 10,000 years covering the entire flood risk chain including hydrological, 1D/2D hydrodynamic and flood damage estimation models. This provided a record of around 2.000 inundation events affecting the study area with spatially detailed information on inundation depths and damage to residential buildings on a resolution of 100 m. This serves as basis for a spatially consistent, flood risk assessment for the Mulde catchment presented in

Performance Assessment Strategies: A computational framework for conceptual design of large roofs

Directory of Open Access Journals (Sweden)

Michela Turrin

2014-01-01

Full Text Available Using engineering performance evaluations to explore design alternatives during the conceptual phase of architectural design helps to understand the relationships between form and performance; and is crucial for developing well-performing final designs. Computer aided conceptual design has the potential to aid the design team in discovering and highlighting these relationships; especially by means of procedural and parametric geometry to support the generation of geometric design, and building performance simulation tools to support performance assessments. However, current tools and methods for computer aided conceptual design in architecture do not explicitly reveal nor allow for backtracking the relationships between performance and geometry of the design. They currently support post-engineering, rather than the early design decisions and the design exploration process. Focusing on large roofs, this research aims at developing a computational design approach to support designers in performance driven explorations. The approach is meant to facilitate the multidisciplinary integration and the learning process of the designer; and not to constrain the process in precompiled procedures or in hard engineering formulations, nor to automatize it by delegating the design creativity to computational procedures. PAS (Performance Assessment Strategies as a method is the main output of the research. It consists of a framework including guidelines and an extensible library of procedures for parametric modelling. It is structured on three parts. Pre-PAS provides guidelines for a design strategy-definition, toward the parameterization process. Model-PAS provides guidelines, procedures and scripts for building the parametric models. Explore-PAS supports the solutions-assessment based on numeric evaluations and performance simulations, until the identification of a suitable design solution. PAS has been developed based on action research. Several case studies

Experimental facilities for large-scale and full-scale study of hydrogen accidents

Energy Technology Data Exchange (ETDEWEB)

Merilo, E.; Groethe, M.; Colton, J. [SRI International, Poulter Laboratory, Menlo Park, CA (United States); Chiba, S. [SRI Japan, Tokyo (Japan)

2007-07-01

This paper summarized some of the work that has been performed at SRI International over the past 5 years that address safety issues for the hydrogen-based economy. Researchers at SRI International have conducted experiments at the Corral Hollow Experiment Site (CHES) near Livermore California to obtain fundamental data on hydrogen explosions for risk assessment. In particular, large-scale hydrogen tests were conducted using homogeneous mixtures of hydrogen in volumes from 5.3 m{sup 3} to 300 m{sup 3} to represent scenarios involving fuel cell vehicles as well as transport and storage facilities. Experiments have focused on unconfined deflagrations of hydrogen and air, and detonations of hydrogen in a semi-open space to measure free-field blast effects; the use of blast walls as a mitigation technique; turbulent enhancement of hydrogen combustion due to obstacles within the mixture, and determination of when deflagration-to-detonation transition occurs; the effect of confined hydrogen releases and explosions that could originate from an interconnecting hydrogen pipeline; and, large and small accidental releases of hydrogen. The experiments were conducted to improve the prediction of hydrogen explosions and the capabilities for performing risk assessments, and to develop mitigation techniques. Measurements included hydrogen concentration; flame speed; blast overpressure; heat flux; and, high-speed, standard, and infrared video. The data collected in these experiments is used to correlate computer models and to facilitate the development of codes and standards. This work contributes to better safety technology by evaluating the effectiveness of different blast mitigation techniques. 13 refs., 13 figs.

The Limits and Possibilities of International Large-Scale Assessments. Education Policy Brief. Volume 9, Number 2, Spring 2011

Science.gov (United States)

Rutkowski, David J.; Prusinski, Ellen L.

2011-01-01

The staff of the Center for Evaluation & Education Policy (CEEP) at Indiana University is often asked about how international large-scale assessments influence U.S. educational policy. This policy brief is designed to provide answers to some of the most frequently asked questions encountered by CEEP researchers concerning the three most popular…

On the Fidelity of Semi-distributed Hydrologic Model Simulations for Large Scale Catchment Applications

Science.gov (United States)

Ajami, H.; Sharma, A.; Lakshmi, V.

2017-12-01

Application of semi-distributed hydrologic modeling frameworks is a viable alternative to fully distributed hyper-resolution hydrologic models due to computational efficiency and resolving fine-scale spatial structure of hydrologic fluxes and states. However, fidelity of semi-distributed model simulations is impacted by (1) formulation of hydrologic response units (HRUs), and (2) aggregation of catchment properties for formulating simulation elements. Here, we evaluate the performance of a recently developed Soil Moisture and Runoff simulation Toolkit (SMART) for large catchment scale simulations. In SMART, topologically connected HRUs are delineated using thresholds obtained from topographic and geomorphic analysis of a catchment, and simulation elements are equivalent cross sections (ECS) representative of a hillslope in first order sub-basins. Earlier investigations have shown that formulation of ECSs at the scale of a first order sub-basin reduces computational time significantly without compromising simulation accuracy. However, the implementation of this approach has not been fully explored for catchment scale simulations. To assess SMART performance, we set-up the model over the Little Washita watershed in Oklahoma. Model evaluations using in-situ soil moisture observations show satisfactory model performance. In addition, we evaluated the performance of a number of soil moisture disaggregation schemes recently developed to provide spatially explicit soil moisture outputs at fine scale resolution. Our results illustrate that the statistical disaggregation scheme performs significantly better than the methods based on topographic data. Future work is focused on assessing the performance of SMART using remotely sensed soil moisture observations using spatially based model evaluation metrics.

Safety Performance Evaluations for the Vehicle Based Movable Barriers Using Full Scale Crash Tests

Directory of Open Access Journals (Sweden)

Jin Minsoo

2017-01-01

Full Text Available The present study aims to develop a prototype of large-size movable barriers to protect roadside workers from incoming vehicles to the road work area with the following functions: maximization of work space in the right and left directions, convenient mobility, and minimization of impact without modification of the inside of movable barriers into traffic lanes and perform safety performance assessment on passengers through full scale crash tests. The large movable barrier was divided into folder type and telescope type and the development stage was now at the prototype phase. A full scale crash test was conducted prior to certification test at a level of 90%. The full scale crash test result showed that both types of folder type movable barrier and telescope type movable barrier satisfied the standard of the passenger safety performance evaluation at a level of 90%.

Evolution of scaling emergence in large-scale spatial epidemic spreading.

Science.gov (United States)

Wang, Lin; Li, Xiang; Zhang, Yi-Qing; Zhang, Yan; Zhang, Kan

2011-01-01

Zipf's law and Heaps' law are two representatives of the scaling concepts, which play a significant role in the study of complexity science. The coexistence of the Zipf's law and the Heaps' law motivates different understandings on the dependence between these two scalings, which has still hardly been clarified. In this article, we observe an evolution process of the scalings: the Zipf's law and the Heaps' law are naturally shaped to coexist at the initial time, while the crossover comes with the emergence of their inconsistency at the larger time before reaching a stable state, where the Heaps' law still exists with the disappearance of strict Zipf's law. Such findings are illustrated with a scenario of large-scale spatial epidemic spreading, and the empirical results of pandemic disease support a universal analysis of the relation between the two laws regardless of the biological details of disease. Employing the United States domestic air transportation and demographic data to construct a metapopulation model for simulating the pandemic spread at the U.S. country level, we uncover that the broad heterogeneity of the infrastructure plays a key role in the evolution of scaling emergence. The analyses of large-scale spatial epidemic spreading help understand the temporal evolution of scalings, indicating the coexistence of the Zipf's law and the Heaps' law depends on the collective dynamics of epidemic processes, and the heterogeneity of epidemic spread indicates the significance of performing targeted containment strategies at the early time of a pandemic disease.

Spatiotemporally enhancing time-series DMSP/OLS nighttime light imagery for assessing large-scale urban dynamics

Science.gov (United States)

Xie, Yanhua; Weng, Qihao

2017-06-01

Accurate, up-to-date, and consistent information of urban extents is vital for numerous applications central to urban planning, ecosystem management, and environmental assessment and monitoring. However, current large-scale urban extent products are not uniform with respect to definition, spatial resolution, temporal frequency, and thematic representation. This study aimed to enhance, spatiotemporally, time-series DMSP/OLS nighttime light (NTL) data for detecting large-scale urban changes. The enhanced NTL time series from 1992 to 2013 were firstly generated by implementing global inter-calibration, vegetation-based spatial adjustment, and urban archetype-based temporal modification. The dataset was then used for updating and backdating urban changes for the contiguous U.S.A. (CONUS) and China by using the Object-based Urban Thresholding method (i.e., NTL-OUT method, Xie and Weng, 2016b). The results showed that the updated urban extents were reasonably accurate, with city-scale RMSE (root mean square error) of 27 km2 and Kappa of 0.65 for CONUS, and 55 km2 and 0.59 for China, respectively. The backdated urban extents yielded similar accuracy, with RMSE of 23 km2 and Kappa of 0.63 in CONUS, while 60 km2 and 0.60 in China. The accuracy assessment further revealed that the spatial enhancement greatly improved the accuracy of urban updating and backdating by significantly reducing RMSE and slightly increasing Kappa values. The temporal enhancement also reduced RMSE, and improved the spatial consistency between estimated and reference urban extents. Although the utilization of enhanced NTL data successfully detected urban size change, relatively low locational accuracy of the detected urban changes was observed. It is suggested that the proposed methodology would be more effective for updating and backdating global urban maps if further fusion of NTL data with higher spatial resolution imagery was implemented.

Large-Scale Brain Network Coupling Predicts Total Sleep Deprivation Effects on Cognitive Capacity.

Directory of Open Access Journals (Sweden)

Yu Lei

Full Text Available Interactions between large-scale brain networks have received most attention in the study of cognitive dysfunction of human brain. In this paper, we aimed to test the hypothesis that the coupling strength of large-scale brain networks will reflect the pressure for sleep and will predict cognitive performance, referred to as sleep pressure index (SPI. Fourteen healthy subjects underwent this within-subject functional magnetic resonance imaging (fMRI study during rested wakefulness (RW and after 36 h of total sleep deprivation (TSD. Self-reported scores of sleepiness were higher for TSD than for RW. A subsequent working memory (WM task showed that WM performance was lower after 36 h of TSD. Moreover, SPI was developed based on the coupling strength of salience network (SN and default mode network (DMN. Significant increase of SPI was observed after 36 h of TSD, suggesting stronger pressure for sleep. In addition, SPI was significantly correlated with both the visual analogue scale score of sleepiness and the WM performance. These results showed that alterations in SN-DMN coupling might be critical in cognitive alterations that underlie the lapse after TSD. Further studies may validate the SPI as a potential clinical biomarker to assess the impact of sleep deprivation.

Ethics of large-scale change

OpenAIRE

Arler, Finn

2006-01-01

  The subject of this paper is long-term large-scale changes in human society. Some very significant examples of large-scale change are presented: human population growth, human appropriation of land and primary production, the human use of fossil fuels, and climate change. The question is posed, which kind of attitude is appropriate when dealing with large-scale changes like these from an ethical point of view. Three kinds of approaches are discussed: Aldo Leopold's mountain thinking, th...

How International Large-Scale Skills Assessments Engage with National Actors: Mobilising Networks through Policy, Media and Public Knowledge

Science.gov (United States)

Hamilton, Mary

2017-01-01

This paper examines how international, large-scale skills assessments (ILSAs) engage with the broader societies they seek to serve and improve. It looks particularly at the discursive work that is done by different interest groups and the media through which the findings become part of public conversations and are translated into usable form in…

LARGE-SCALE COMMERCIAL INVESTMENTS IN LAND: SEEKING ...

African Journals Online (AJOL)

extent of large-scale investment in land or to assess its impact on the people in recipient countries. .... favorable lease terms, apparently based on a belief that this is necessary to .... Harm to the rights of local occupiers of land can result from a dearth. 24. ..... applies to a self-identified group based on the group's traditions.

Comparing the Effectiveness of Self-Paced and Collaborative Frame-of-Reference Training on Rater Accuracy in a Large-Scale Writing Assessment

Science.gov (United States)

Raczynski, Kevin R.; Cohen, Allan S.; Engelhard, George, Jr.; Lu, Zhenqiu

2015-01-01

There is a large body of research on the effectiveness of rater training methods in the industrial and organizational psychology literature. Less has been reported in the measurement literature on large-scale writing assessments. This study compared the effectiveness of two widely used rater training methods--self-paced and collaborative…

Embedded Electro-Optic Sensor Network for the On-Site Calibration and Real-Time Performance Monitoring of Large-Scale Phased Arrays

National Research Council Canada - National Science Library

Yang, Kyoung

2005-01-01

This final report summarizes the progress during the Phase I SBIR project entitled "Embedded Electro-Optic Sensor Network for the On-Site Calibration and Real-Time Performance Monitoring of Large-Scale Phased Arrays...

Study on large scale knowledge base with real time operation for autonomous nuclear power plant. 1. Basic concept and expecting performance

International Nuclear Information System (INIS)

Ozaki, Yoshihiko; Suda, Kazunori; Yoshikawa, Shinji; Ozawa, Kenji

1996-04-01

Since it is desired to enhance availability and safety of nuclear power plants operation and maintenance by removing human factor, there are many researches and developments for intelligent operation or diagnosis using artificial intelligence (AI) technique. We have been developing an autonomous operation and maintenance system for nuclear power plants by substituting AI's and intelligent robots. It is indispensable to use various and large scale knowledge relative to plant design, operation, and maintenance, that is, whole life cycle data of the plant for the autonomous nuclear power plant. These knowledge must be given to AI system or intelligent robots adequately and opportunely. Moreover, it is necessary to insure real time operation using the large scale knowledge base for plant control and diagnosis performance. We have been studying on the large scale and real time knowledge base system for autonomous plant. In the report, we would like to present the basic concept and expecting performance of the knowledge base for autonomous plant, especially, autonomous control and diagnosis system. (author)

Analysis of the applicability of fracture mechanics on the basis of large scale specimen testing

International Nuclear Information System (INIS)

Brumovsky, M.; Polachova, H.; Sulc, J.; Anikovskij, V.; Dragunov, Y.; Rivkin, E.; Filatov, V.

1988-01-01

The verification is dealt with of fracture mechanics calculations for WWER reactor pressure vessels by large scale model testing performed on the large testing machine ZZ 8000 (maximum load of 80 MN) in the Skoda Concern. The results of testing a large set of large scale test specimens with surface crack-type defects are presented. The nominal thickness of the specimens was 150 mm with defect depths between 15 and 100 mm, the testing temperature varying between -30 and +80 degC (i.e., in the temperature interval of T ko ±50 degC). Specimens with a scale of 1:8 and 1:12 were also tested, as well as standard (CT and TPB) specimens. Comparisons of results of testing and calculations suggest some conservatism of calculations (especially for small defects) based on Linear Elastic Fracture Mechanics, according to the Nuclear Reactor Pressure Vessel Codes which use the fracture mechanics values from J IC testing. On the basis of large scale tests the ''Defect Analysis Diagram'' was constructed and recommended for brittle fracture assessment of reactor pressure vessels. (author). 7 figs., 2 tabs., 3 refs

Assessing the Performance of Large Scale Green Roofs and Their Impact on the Urban Microclimate

Science.gov (United States)

Smalls-Mantey, L.; Foti, R.; Montalto, F. A.

2015-12-01

In ultra-urban environments green roofs offer a feasible solution to add green infrastructure (GI) in neighborhoods where space is limited. Green roofs offer the typical advantages of urban GI such as stormwater reduction and management while providing direct benefits to the buildings on which they are installed through thermal protection and mitigation of temperature fluctuations. At 6.8 acres, the Jacob K. Javits Convention Center (JJCC) in New York City, hosts the second largest green roof in the United States. Since its installation in August 2013, the Sustainable Water Resource (SWRE) Laboratory at Drexel University has monitored the climate on and around the green roof by means of four weather stations situated on various roof and ground locations. Using two years of fine scale climatic data collected at the JJCC, this study explores the energy balance of a large scale green roof system. Temperature, radiation, evapotranspiration and wind profiles pre- and post- installation of the JJCC green roof were analyzed and compared across monitored locations, with the goal of identifying the impact of the green roof on the building and urban micro-climate. Our findings indicate that the presence of the green roof, not only altered the climatic conditions above the JJCC, but also had a measurable impact on the climatic profile of the areas immediately surrounding it. Furthermore, as a result of the mitigation of roof temperature fluctuations and of the cooling provided during warmer months, an improvement of the building thermal efficiency was contextually observed. Such findings support the installation of GI as an effective practice in urban settings and important in the discussion of key issues including energy conservation measures, carbon emission reductions and the mitigation of urban heat islands.

Large-scale dynamic compaction demonstration using WIPP salt: Fielding and preliminary results

International Nuclear Information System (INIS)

Ahrens, E.H.; Hansen, F.D.

1995-10-01

Reconsolidation of crushed rock salt is a phenomenon of great interest to programs studying isolation of hazardous materials in natural salt geologic settings. Of particular interest is the potential for disaggregated salt to be restored to nearly an impermeable state. For example, reconsolidated crushed salt is proposed as a major shaft seal component for the Waste Isolation Pilot Plant (WIPP) Project. The concept for a permanent shaft seal component of the WIPP repository is to densely compact crushed salt in the four shafts; an effective seal will then be developed as the surrounding salt creeps into the shafts, further consolidating the crushed salt. Fundamental information on placement density and permeability is required to ensure attainment of the design function. The work reported here is the first large-scale compaction demonstration to provide information on initial salt properties applicable to design, construction, and performance expectations. The shaft seals must function for 10,000 years. Over this period a crushed salt mass will become less permeable as it is compressed by creep closure of salt surrounding the shaft. These facts preclude the possibility of conducting a full-scale, real-time field test. Because permanent seals taking advantage of salt reconsolidation have never been constructed, performance measurements have not been made on an appropriately large scale. An understanding of potential construction methods, achievable initial density and permeability, and performance of reconsolidated salt over time is required for seal design and performance assessment. This report discusses fielding and operations of a nearly full-scale dynamic compaction of mine-run WIPP salt, and presents preliminary density and in situ (in place) gas permeability results

Image-based Exploration of Large-Scale Pathline Fields

KAUST Repository

Nagoor, Omniah H.

2014-05-27

While real-time applications are nowadays routinely used in visualizing large nu- merical simulations and volumes, handling these large-scale datasets requires high-end graphics clusters or supercomputers to process and visualize them. However, not all users have access to powerful clusters. Therefore, it is challenging to come up with a visualization approach that provides insight to large-scale datasets on a single com- puter. Explorable images (EI) is one of the methods that allows users to handle large data on a single workstation. Although it is a view-dependent method, it combines both exploration and modification of visual aspects without re-accessing the original huge data. In this thesis, we propose a novel image-based method that applies the concept of EI in visualizing large flow-field pathlines data. The goal of our work is to provide an optimized image-based method, which scales well with the dataset size. Our approach is based on constructing a per-pixel linked list data structure in which each pixel contains a list of pathlines segments. With this view-dependent method it is possible to filter, color-code and explore large-scale flow data in real-time. In addition, optimization techniques such as early-ray termination and deferred shading are applied, which further improves the performance and scalability of our approach.

Large-scale Labeled Datasets to Fuel Earth Science Deep Learning Applications

Science.gov (United States)

Maskey, M.; Ramachandran, R.; Miller, J.

2017-12-01

Deep learning has revolutionized computer vision and natural language processing with various algorithms scaled using high-performance computing. However, generic large-scale labeled datasets such as the ImageNet are the fuel that drives the impressive accuracy of deep learning results. Large-scale labeled datasets already exist in domains such as medical science, but creating them in the Earth science domain is a challenge. While there are ways to apply deep learning using limited labeled datasets, there is a need in the Earth sciences for creating large-scale labeled datasets for benchmarking and scaling deep learning applications. At the NASA Marshall Space Flight Center, we are using deep learning for a variety of Earth science applications where we have encountered the need for large-scale labeled datasets. We will discuss our approaches for creating such datasets and why these datasets are just as valuable as deep learning algorithms. We will also describe successful usage of these large-scale labeled datasets with our deep learning based applications.

Hydrometeorological variability on a large french catchment and its relation to large-scale circulation across temporal scales

Science.gov (United States)

Massei, Nicolas; Dieppois, Bastien; Fritier, Nicolas; Laignel, Benoit; Debret, Maxime; Lavers, David; Hannah, David

2015-04-01

In the present context of global changes, considerable efforts have been deployed by the hydrological scientific community to improve our understanding of the impacts of climate fluctuations on water resources. Both observational and modeling studies have been extensively employed to characterize hydrological changes and trends, assess the impact of climate variability or provide future scenarios of water resources. In the aim of a better understanding of hydrological changes, it is of crucial importance to determine how and to what extent trends and long-term oscillations detectable in hydrological variables are linked to global climate oscillations. In this work, we develop an approach associating large-scale/local-scale correlation, enmpirical statistical downscaling and wavelet multiresolution decomposition of monthly precipitation and streamflow over the Seine river watershed, and the North Atlantic sea level pressure (SLP) in order to gain additional insights on the atmospheric patterns associated with the regional hydrology. We hypothesized that: i) atmospheric patterns may change according to the different temporal wavelengths defining the variability of the signals; and ii) definition of those hydrological/circulation relationships for each temporal wavelength may improve the determination of large-scale predictors of local variations. The results showed that the large-scale/local-scale links were not necessarily constant according to time-scale (i.e. for the different frequencies characterizing the signals), resulting in changing spatial patterns across scales. This was then taken into account by developing an empirical statistical downscaling (ESD) modeling approach which integrated discrete wavelet multiresolution analysis for reconstructing local hydrometeorological processes (predictand : precipitation and streamflow on the Seine river catchment) based on a large-scale predictor (SLP over the Euro-Atlantic sector) on a monthly time-step. This approach

Simulation of buoyancy induced gas mixing tests performed in a large scale containment facility using GOTHIC code

Energy Technology Data Exchange (ETDEWEB)

Liang, Z.; Chin, Y.S. [Atomic Energy of Canada Limited, Chalk River, ON (Canada)

2014-07-01

This paper compares containment thermal-hydraulics simulations performed using GOTHIC against a past test set of large scale buoyancy induced helium-air-steam mixing experiments that had been performed at the AECL's Chalk River Laboratories. A number of typical post-accident containment phenomena, including thermal/gas stratification, natural convection, cool air entrainment, steam condensation on concrete walls and active local air cooler, were covered. The results provide useful insights into hydrogen gas mixing behaviour following a loss-of-coolant accident and demonstrate GOTHIC's capability in simulating these phenomena. (author)

Simulation of buoyancy induced gas mixing tests performed in a large scale containment facility using GOTHIC code

International Nuclear Information System (INIS)

Liang, Z.; Chin, Y.S.

2014-01-01

This paper compares containment thermal-hydraulics simulations performed using GOTHIC against a past test set of large scale buoyancy induced helium-air-steam mixing experiments that had been performed at the AECL's Chalk River Laboratories. A number of typical post-accident containment phenomena, including thermal/gas stratification, natural convection, cool air entrainment, steam condensation on concrete walls and active local air cooler, were covered. The results provide useful insights into hydrogen gas mixing behaviour following a loss-of-coolant accident and demonstrate GOTHIC's capability in simulating these phenomena. (author)

Large-scale assessment of olfactory preferences and learning in Drosophila melanogaster: behavioral and genetic components

Directory of Open Access Journals (Sweden)

Elisabetta Versace

2015-09-01

Full Text Available In the Evolve and Resequence method (E&R, experimental evolution and genomics are combined to investigate evolutionary dynamics and the genotype-phenotype link. As other genomic approaches, this methods requires many replicates with large population sizes, which imposes severe restrictions on the analysis of behavioral phenotypes. Aiming to use E&R for investigating the evolution of behavior in Drosophila, we have developed a simple and effective method to assess spontaneous olfactory preferences and learning in large samples of fruit flies using a T-maze. We tested this procedure on (a a large wild-caught population and (b 11 isofemale lines of Drosophila melanogaster. Compared to previous methods, this procedure reduces the environmental noise and allows for the analysis of large population samples. Consistent with previous results, we show that flies have a preference for orange vs. apple odor. With our procedure wild-derived flies exhibit olfactory learning in the absence of previous laboratory selection. Furthermore, we find genetic differences in the olfactory learning with relatively high heritability. We propose this large-scale method as an effective tool for E&R and genome-wide association studies on olfactory preferences and learning.

Assessing Programming Costs of Explicit Memory Localization on a Large Scale Shared Memory Multiprocessor

Directory of Open Access Journals (Sweden)

Silvio Picano

1992-01-01

Full Text Available We present detailed experimental work involving a commercially available large scale shared memory multiple instruction stream-multiple data stream (MIMD parallel computer having a software controlled cache coherence mechanism. To make effective use of such an architecture, the programmer is responsible for designing the program's structure to match the underlying multiprocessors capabilities. We describe the techniques used to exploit our multiprocessor (the BBN TC2000 on a network simulation program, showing the resulting performance gains and the associated programming costs. We show that an efficient implementation relies heavily on the user's ability to explicitly manage the memory system.

Performance of the first Japanese large-scale facility for radon inhalation experiments with small animals

International Nuclear Information System (INIS)

Ishimori, Y.; Mitsunobu, F.; Yamaoka, K.; Tanaka, H.; Kataoka, T.; Sakoda, A.

2011-01-01

A radon test facility for small animals was developed in order to increase the statistical validity of differences of the biological response in various radon environments. This paper illustrates the performances of that facility, the first large-scale facility of its kind in Japan. The facility has a capability to conduct approximately 150 mouse-scale tests at the same time. The apparatus for exposing small animals to radon has six animal chamber groups with five independent cages each. Different radon concentrations in each animal chamber group are available. Because the first target of this study is to examine the in vivo behaviour of radon and its effects, the major functions to control radon and to eliminate thoron were examined experimentally. Additionally, radon progeny concentrations and their particle size distributions in the cages were also examined experimentally to be considered in future projects. (authors)

Using GRACE Satellite Gravimetry for Assessing Large-Scale Hydrologic Extremes

Directory of Open Access Journals (Sweden)

Alexander Y. Sun

2017-12-01

Full Text Available Global assessment of the spatiotemporal variability in terrestrial total water storage anomalies (TWSA in response to hydrologic extremes is critical for water resources management. Using TWSA derived from the gravity recovery and climate experiment (GRACE satellites, this study systematically assessed the skill of the TWSA-climatology (TC approach and breakpoint (BP detection method for identifying large-scale hydrologic extremes. The TC approach calculates standardized anomalies by using the mean and standard deviation of the GRACE TWSA corresponding to each month. In the BP detection method, the empirical mode decomposition (EMD is first applied to identify the mean return period of TWSA extremes, and then a statistical procedure is used to identify the actual occurrence times of abrupt changes (i.e., BPs in TWSA. Both detection methods were demonstrated on basin-averaged TWSA time series for the world’s 35 largest river basins. A nonlinear event coincidence analysis measure was applied to cross-examine abrupt changes detected by these methods with those detected by the Standardized Precipitation Index (SPI. Results show that our EMD-assisted BP procedure is a promising tool for identifying hydrologic extremes using GRACE TWSA data. Abrupt changes detected by the BP method coincide well with those of the SPI anomalies and with documented hydrologic extreme events. Event timings obtained by the TC method were ambiguous for a number of river basins studied, probably because the GRACE data length is too short to derive long-term climatology at this time. The BP approach demonstrates a robust wet-dry anomaly detection capability, which will be important for applications with the upcoming GRACE Follow-On mission.

Large Scale Solar Heating

DEFF Research Database (Denmark)

Heller, Alfred

2001-01-01

The main objective of the research was to evaluate large-scale solar heating connected to district heating (CSDHP), to build up a simulation tool and to demonstrate the application of the simulation tool for design studies and on a local energy planning case. The evaluation was mainly carried out...... model is designed and validated on the Marstal case. Applying the Danish Reference Year, a design tool is presented. The simulation tool is used for proposals for application of alternative designs, including high-performance solar collector types (trough solar collectors, vaccum pipe collectors......). Simulation programs are proposed as control supporting tool for daily operation and performance prediction of central solar heating plants. Finaly the CSHP technolgy is put into persepctive with respect to alternatives and a short discussion on the barries and breakthrough of the technology are given....

Personality Assessment Inventory scale characteristics and factor structure in the assessment of alcohol dependency.

Science.gov (United States)

Schinka, J A

1995-02-01

Individual scale characteristics and the inventory structure of the Personality Assessment Inventory (PAI; Morey, 1991) were examined by conducting internal consistency and factor analyses of item and scale score data from a large group (N = 301) of alcohol-dependent patients. Alpha coefficients, mean inter-item correlations, and corrected item-total scale correlations for the sample paralleled values reported by Morey for a large clinical sample. Minor differences in the scale factor structure of the inventory from Morey's clinical sample were found. Overall, the findings support the use of the PAI in the assessment of personality and psychopathology of alcohol-dependent patients.

Energy performance strategies for the large scale introduction of geothermal energy in residential and industrial buildings: The GEO.POWER project

International Nuclear Information System (INIS)

Giambastiani, B.M.S.; Tinti, F.; Mendrinos, D.; Mastrocicco, M.

2014-01-01

Use of shallow geothermal energy, in terms of ground coupled heat pumps (GCHP) for heating and cooling purposes, is an environmentally-friendly and cost-effective alternative with potential to replace fossil fuels and help mitigate global warming. Focusing on the recent results of the GEO.POWER project, this paper aims at examining the energy performance strategies and the future regional and national financial instruments for large scale introduction of geothermal energy and GCHP systems in both residential and industrial buildings. After a transferability assessment to evaluate the reproducibility of some outstanding examples of systems currently existing in Europe for the utilisation of shallow geothermal energy, a set of regulatory, economic and technical actions is proposed to encourage the GCHP market development and support geothermal energy investments in the frame of the existing European normative platforms. This analysis shows that many European markets are changing from a new GCHP market to growth market. However some interventions are still required, such as incentives, regulatory framework, certification schemes and training activities in order to accelerate the market uptake and achieve the main European energy and climate targets. - Highlights: • Potentiality of geothermal applications for heating and cooling in buildings. • Description of the GEO.POWER project and its results. • Local strategies for the large scale introduction of GCHPs

Environmental impact assessment and environmental audit in large-scale public infrastructure construction: the case of the Qinghai-Tibet Railway.

Science.gov (United States)

He, Guizhen; Zhang, Lei; Lu, Yonglong

2009-09-01

Large-scale public infrastructure projects have featured in China's modernization course since the early 1980s. During the early stages of China's rapid economic development, public attention focused on the economic and social impact of high-profile construction projects. In recent years, however, we have seen a shift in public concern toward the environmental and ecological effects of such projects, and today governments are required to provide valid environmental impact assessments prior to allowing large-scale construction. The official requirement for the monitoring of environmental conditions has led to an increased number of debates in recent years regarding the effectiveness of Environmental Impact Assessments (EIAs) and Governmental Environmental Audits (GEAs) as environmental safeguards in instances of large-scale construction. Although EIA and GEA are conducted by different institutions and have different goals and enforcement potential, these two practices can be closely related in terms of methodology. This article cites the construction of the Qinghai-Tibet Railway as an instance in which EIA and GEA offer complementary approaches to environmental impact management. This study concludes that the GEA approach can serve as an effective follow-up to the EIA and establishes that the EIA lays a base for conducting future GEAs. The relationship that emerges through a study of the Railway's construction calls for more deliberate institutional arrangements and cooperation if the two practices are to be used in concert to optimal effect.

Solution approach for a large scale personnel transport system for a large company in Latin America

Energy Technology Data Exchange (ETDEWEB)

Garzón-Garnica, Eduardo-Arturo; Caballero-Morales, Santiago-Omar; Martínez-Flores, José-Luis

2017-07-01

The present paper focuses on the modelling and solution of a large-scale personnel transportation system in Mexico where many routes and vehicles are currently used to service 525 points. The routing system proposed can be applied to many cities in the Latin-American region. Design/methodology/approach: This system was modelled as a VRP model considering the use of real-world transit times, and the fact that routes start at the farthest point from the destination center. Experiments were performed on different sized sets of service points. As the size of the instances was increased, the performance of the heuristic method was assessed in comparison with the results of an exact algorithm, the results remaining very close between both. When the size of the instance was full-scale and the exact algorithm took too much time to solve the problem, then the heuristic algorithm provided a feasible solution. Supported by the validation with smaller scale instances, where the difference between both solutions was close to a 6%, the full –scale solution obtained with the heuristic algorithm was considered to be within that same range. Findings: The proposed modelling and solving method provided a solution that would produce significant savings in the daily operation of the routes. Originality/value: The urban distribution of the cities in Latin America is unique to other regions in the world. The general layout of the large cities in this region includes a small town center, usually antique, and a somewhat disordered outer region. The lack of a vehicle-centered urban planning poses distinct challenges for vehicle routing problems in the region. The use of a heuristic VRP combined with the results of an exact VRP, allowed the obtention of an improved routing plan specific to the requirements of the region.

Solution approach for a large scale personnel transport system for a large company in Latin America

International Nuclear Information System (INIS)

Garzón-Garnica, Eduardo-Arturo; Caballero-Morales, Santiago-Omar; Martínez-Flores, José-Luis

2017-01-01

The present paper focuses on the modelling and solution of a large-scale personnel transportation system in Mexico where many routes and vehicles are currently used to service 525 points. The routing system proposed can be applied to many cities in the Latin-American region. Design/methodology/approach: This system was modelled as a VRP model considering the use of real-world transit times, and the fact that routes start at the farthest point from the destination center. Experiments were performed on different sized sets of service points. As the size of the instances was increased, the performance of the heuristic method was assessed in comparison with the results of an exact algorithm, the results remaining very close between both. When the size of the instance was full-scale and the exact algorithm took too much time to solve the problem, then the heuristic algorithm provided a feasible solution. Supported by the validation with smaller scale instances, where the difference between both solutions was close to a 6%, the full –scale solution obtained with the heuristic algorithm was considered to be within that same range. Findings: The proposed modelling and solving method provided a solution that would produce significant savings in the daily operation of the routes. Originality/value: The urban distribution of the cities in Latin America is unique to other regions in the world. The general layout of the large cities in this region includes a small town center, usually antique, and a somewhat disordered outer region. The lack of a vehicle-centered urban planning poses distinct challenges for vehicle routing problems in the region. The use of a heuristic VRP combined with the results of an exact VRP, allowed the obtention of an improved routing plan specific to the requirements of the region.

Solution approach for a large scale personnel transport system for a large company in Latin America

Directory of Open Access Journals (Sweden)

Eduardo-Arturo Garzón-Garnica

2017-10-01

Full Text Available Purpose: The present paper focuses on the modelling and solution of a large-scale personnel transportation system in Mexico where many routes and vehicles are currently used to service 525 points. The routing system proposed can be applied to many cities in the Latin-American region. Design/methodology/approach: This system was modelled as a VRP model considering the use of real-world transit times, and the fact that routes start at the farthest point from the destination center. Experiments were performed on different sized sets of service points. As the size of the instances was increased, the performance of the heuristic method was assessed in comparison with the results of an exact algorithm, the results remaining very close between both.  When the size of the instance was full-scale and the exact algorithm took too much time to solve the problem, then the heuristic algorithm provided a feasible solution. Supported by the validation with smaller scale instances, where the difference between both solutions was close to a 6%, the full –scale solution obtained with the heuristic algorithm was considered to be within that same range. Findings: The proposed modelling and solving method provided a solution that would produce significant savings in the daily operation of the routes. Originality/value: The urban distribution of the cities in Latin America is unique to other regions in the world. The general layout of the large cities in this region includes a small town center, usually antique, and a somewhat disordered outer region. The lack of a vehicle-centered urban planning poses distinct challenges for vehicle routing problems in the region. The use of a heuristic VRP combined with the results of an exact VRP, allowed the obtention of an improved routing plan specific to the requirements of the region.

Political consultation and large-scale research

International Nuclear Information System (INIS)

Bechmann, G.; Folkers, H.

1977-01-01

Large-scale research and policy consulting have an intermediary position between sociological sub-systems. While large-scale research coordinates science, policy, and production, policy consulting coordinates science, policy and political spheres. In this very position, large-scale research and policy consulting lack of institutional guarantees and rational back-ground guarantee which are characteristic for their sociological environment. This large-scale research can neither deal with the production of innovative goods under consideration of rentability, nor can it hope for full recognition by the basis-oriented scientific community. Policy consulting knows neither the competence assignment of the political system to make decisions nor can it judge succesfully by the critical standards of the established social science, at least as far as the present situation is concerned. This intermediary position of large-scale research and policy consulting has, in three points, a consequence supporting the thesis which states that this is a new form of institutionalization of science: These are: 1) external control, 2) the organization form, 3) the theoretical conception of large-scale research and policy consulting. (orig.) [de

Accelerating large-scale phase-field simulations with GPU

Directory of Open Access Journals (Sweden)

Xiaoming Shi

2017-10-01

Full Text Available A new package for accelerating large-scale phase-field simulations was developed by using GPU based on the semi-implicit Fourier method. The package can solve a variety of equilibrium equations with different inhomogeneity including long-range elastic, magnetostatic, and electrostatic interactions. Through using specific algorithm in Compute Unified Device Architecture (CUDA, Fourier spectral iterative perturbation method was integrated in GPU package. The Allen-Cahn equation, Cahn-Hilliard equation, and phase-field model with long-range interaction were solved based on the algorithm running on GPU respectively to test the performance of the package. From the comparison of the calculation results between the solver executed in single CPU and the one on GPU, it was found that the speed on GPU is enormously elevated to 50 times faster. The present study therefore contributes to the acceleration of large-scale phase-field simulations and provides guidance for experiments to design large-scale functional devices.

Performance Characteristics of Hybrid MPI/OpenMP Scientific Applications on a Large-Scale Multithreaded BlueGene/Q Supercomputer

KAUST Repository

Wu, Xingfu; Taylor, Valerie

2013-01-01

In this paper, we investigate the performance characteristics of five hybrid MPI/OpenMP scientific applications (two NAS Parallel benchmarks Multi-Zone SP-MZ and BT-MZ, an earthquake simulation PEQdyna, an aerospace application PMLB and a 3D particle-in-cell application GTC) on a large-scale multithreaded Blue Gene/Q supercomputer at Argonne National laboratory, and quantify the performance gap resulting from using different number of threads per node. We use performance tools and MPI profile and trace libraries available on the supercomputer to analyze and compare the performance of these hybrid scientific applications with increasing the number OpenMP threads per node, and find that increasing the number of threads to some extent saturates or worsens performance of these hybrid applications. For the strong-scaling hybrid scientific applications such as SP-MZ, BT-MZ, PEQdyna and PLMB, using 32 threads per node results in much better application efficiency than using 64 threads per node, and as increasing the number of threads per node, the FPU (Floating Point Unit) percentage decreases, and the MPI percentage (except PMLB) and IPC (Instructions per cycle) per core (except BT-MZ) increase. For the weak-scaling hybrid scientific application such as GTC, the performance trend (relative speedup) is very similar with increasing number of threads per node no matter how many nodes (32, 128, 512) are used. © 2013 IEEE.

Performance Characteristics of Hybrid MPI/OpenMP Scientific Applications on a Large-Scale Multithreaded BlueGene/Q Supercomputer

KAUST Repository

Wu, Xingfu

2013-07-01

In this paper, we investigate the performance characteristics of five hybrid MPI/OpenMP scientific applications (two NAS Parallel benchmarks Multi-Zone SP-MZ and BT-MZ, an earthquake simulation PEQdyna, an aerospace application PMLB and a 3D particle-in-cell application GTC) on a large-scale multithreaded Blue Gene/Q supercomputer at Argonne National laboratory, and quantify the performance gap resulting from using different number of threads per node. We use performance tools and MPI profile and trace libraries available on the supercomputer to analyze and compare the performance of these hybrid scientific applications with increasing the number OpenMP threads per node, and find that increasing the number of threads to some extent saturates or worsens performance of these hybrid applications. For the strong-scaling hybrid scientific applications such as SP-MZ, BT-MZ, PEQdyna and PLMB, using 32 threads per node results in much better application efficiency than using 64 threads per node, and as increasing the number of threads per node, the FPU (Floating Point Unit) percentage decreases, and the MPI percentage (except PMLB) and IPC (Instructions per cycle) per core (except BT-MZ) increase. For the weak-scaling hybrid scientific application such as GTC, the performance trend (relative speedup) is very similar with increasing number of threads per node no matter how many nodes (32, 128, 512) are used. © 2013 IEEE.

Design study on sodium cooled large-scale reactor

International Nuclear Information System (INIS)

Murakami, Tsutomu; Hishida, Masahiko; Kisohara, Naoyuki

2004-07-01

In Phase 1 of the 'Feasibility Studies on Commercialized Fast Reactor Cycle Systems (F/S)', an advanced loop type reactor has been selected as a promising concept of sodium-cooled large-scale reactor, which has a possibility to fulfill the design requirements of the F/S. In Phase 2, design improvement for further cost reduction of establishment of the plant concept has been performed. This report summarizes the results of the design study on the sodium-cooled large-scale reactor performed in JFY2003, which is the third year of Phase 2. In the JFY2003 design study, critical subjects related to safety, structural integrity and thermal hydraulics which found in the last fiscal year has been examined and the plant concept has been modified. Furthermore, fundamental specifications of main systems and components have been set and economy has been evaluated. In addition, as the interim evaluation of the candidate concept of the FBR fuel cycle is to be conducted, cost effectiveness and achievability for the development goal were evaluated and the data of the three large-scale reactor candidate concepts were prepared. As a results of this study, the plant concept of the sodium-cooled large-scale reactor has been constructed, which has a prospect to satisfy the economic goal (construction cost: less than 200,000 yens/kWe, etc.) and has a prospect to solve the critical subjects. From now on, reflecting the results of elemental experiments, the preliminary conceptual design of this plant will be preceded toward the selection for narrowing down candidate concepts at the end of Phase 2. (author)

A method for the assessment of the visual impact caused by the large-scale deployment of renewable-energy facilities

International Nuclear Information System (INIS)

Rodrigues, Marcos; Montanes, Carlos; Fueyo, Norberto

2010-01-01

The production of energy from renewable sources requires a significantly larger use of the territory compared with conventional (fossil and nuclear) sources. For large penetrations of renewable technologies, such as wind power, the overall visual impact at the national level can be substantial, and may prompt public reaction. This study develops a methodology for the assessment of the visual impact that can be used to measure and report the level of impact caused by several renewable technologies (wind farms, solar photovoltaic plants or solar thermal ones), both at the local and regional (e.g. national) scales. Applications are shown to several large-scale, hypothetical scenarios of wind and solar-energy penetration in Spain, and also to the vicinity of an actual, single wind farm.

Approaches to large scale unsaturated flow in heterogeneous, stratified, and fractured geologic media

International Nuclear Information System (INIS)

Ababou, R.

1991-08-01

This report develops a broad review and assessment of quantitative modeling approaches and data requirements for large-scale subsurface flow in radioactive waste geologic repository. The data review includes discussions of controlled field experiments, existing contamination sites, and site-specific hydrogeologic conditions at Yucca Mountain. Local-scale constitutive models for the unsaturated hydrodynamic properties of geologic media are analyzed, with particular emphasis on the effect of structural characteristics of the medium. The report further reviews and analyzes large-scale hydrogeologic spatial variability from aquifer data, unsaturated soil data, and fracture network data gathered from the literature. Finally, various modeling strategies toward large-scale flow simulations are assessed, including direct high-resolution simulation, and coarse-scale simulation based on auxiliary hydrodynamic models such as single equivalent continuum and dual-porosity continuum. The roles of anisotropy, fracturing, and broad-band spatial variability are emphasized. 252 refs

Exploiting Data Sparsity for Large-Scale Matrix Computations

KAUST Repository

Akbudak, Kadir

2018-02-24

Exploiting data sparsity in dense matrices is an algorithmic bridge between architectures that are increasingly memory-austere on a per-core basis and extreme-scale applications. The Hierarchical matrix Computations on Manycore Architectures (HiCMA) library tackles this challenging problem by achieving significant reductions in time to solution and memory footprint, while preserving a specified accuracy requirement of the application. HiCMA provides a high-performance implementation on distributed-memory systems of one of the most widely used matrix factorization in large-scale scientific applications, i.e., the Cholesky factorization. It employs the tile low-rank data format to compress the dense data-sparse off-diagonal tiles of the matrix. It then decomposes the matrix computations into interdependent tasks and relies on the dynamic runtime system StarPU for asynchronous out-of-order scheduling, while allowing high user-productivity. Performance comparisons and memory footprint on matrix dimensions up to eleven million show a performance gain and memory saving of more than an order of magnitude for both metrics on thousands of cores, against state-of-the-art open-source and vendor optimized numerical libraries. This represents an important milestone in enabling large-scale matrix computations toward solving big data problems in geospatial statistics for climate/weather forecasting applications.

Exploiting Data Sparsity for Large-Scale Matrix Computations

KAUST Repository

Akbudak, Kadir; Ltaief, Hatem; Mikhalev, Aleksandr; Charara, Ali; Keyes, David E.

2018-01-01

Exploiting data sparsity in dense matrices is an algorithmic bridge between architectures that are increasingly memory-austere on a per-core basis and extreme-scale applications. The Hierarchical matrix Computations on Manycore Architectures (HiCMA) library tackles this challenging problem by achieving significant reductions in time to solution and memory footprint, while preserving a specified accuracy requirement of the application. HiCMA provides a high-performance implementation on distributed-memory systems of one of the most widely used matrix factorization in large-scale scientific applications, i.e., the Cholesky factorization. It employs the tile low-rank data format to compress the dense data-sparse off-diagonal tiles of the matrix. It then decomposes the matrix computations into interdependent tasks and relies on the dynamic runtime system StarPU for asynchronous out-of-order scheduling, while allowing high user-productivity. Performance comparisons and memory footprint on matrix dimensions up to eleven million show a performance gain and memory saving of more than an order of magnitude for both metrics on thousands of cores, against state-of-the-art open-source and vendor optimized numerical libraries. This represents an important milestone in enabling large-scale matrix computations toward solving big data problems in geospatial statistics for climate/weather forecasting applications.

Matrix Sampling of Items in Large-Scale Assessments

Directory of Open Access Journals (Sweden)

Ruth A. Childs

2003-07-01

Full Text Available Matrix sampling of items -' that is, division of a set of items into different versions of a test form..-' is used by several large-scale testing programs. Like other test designs, matrixed designs have..both advantages and disadvantages. For example, testing time per student is less than if each..student received all the items, but the comparability of student scores may decrease. Also,..curriculum coverage is maintained, but reporting of scores becomes more complex. In this paper,..matrixed designs are compared with more traditional designs in nine categories of costs:..development costs, materials costs, administration costs, educational costs, scoring costs,..reliability costs, comparability costs, validity costs, and reporting costs. In choosing among test..designs, a testing program should examine the costs in light of its mandate(s, the content of the..tests, and the financial resources available, among other considerations.

Hydrogen combustion modelling in large-scale geometries

International Nuclear Information System (INIS)

Studer, E.; Beccantini, A.; Kudriakov, S.; Velikorodny, A.

2014-01-01

Hydrogen risk mitigation issues based on catalytic recombiners cannot exclude flammable clouds to be formed during the course of a severe accident in a Nuclear Power Plant. Consequences of combustion processes have to be assessed based on existing knowledge and state of the art in CFD combustion modelling. The Fukushima accidents have also revealed the need for taking into account the hydrogen explosion phenomena in risk management. Thus combustion modelling in a large-scale geometry is one of the remaining severe accident safety issues. At present day there doesn't exist a combustion model which can accurately describe a combustion process inside a geometrical configuration typical of the Nuclear Power Plant (NPP) environment. Therefore the major attention in model development has to be paid on the adoption of existing approaches or creation of the new ones capable of reliably predicting the possibility of the flame acceleration in the geometries of that type. A set of experiments performed previously in RUT facility and Heiss Dampf Reactor (HDR) facility is used as a validation database for development of three-dimensional gas dynamic model for the simulation of hydrogen-air-steam combustion in large-scale geometries. The combustion regimes include slow deflagration, fast deflagration, and detonation. Modelling is based on Reactive Discrete Equation Method (RDEM) where flame is represented as an interface separating reactants and combustion products. The transport of the progress variable is governed by different flame surface wrinkling factors. The results of numerical simulation are presented together with the comparisons, critical discussions and conclusions. (authors)

Large-scale bioenergy production: how to resolve sustainability trade-offs?

Science.gov (United States)

Humpenöder, Florian; Popp, Alexander; Bodirsky, Benjamin Leon; Weindl, Isabelle; Biewald, Anne; Lotze-Campen, Hermann; Dietrich, Jan Philipp; Klein, David; Kreidenweis, Ulrich; Müller, Christoph; Rolinski, Susanne; Stevanovic, Miodrag

2018-02-01

Large-scale 2nd generation bioenergy deployment is a key element of 1.5 °C and 2 °C transformation pathways. However, large-scale bioenergy production might have negative sustainability implications and thus may conflict with the Sustainable Development Goal (SDG) agenda. Here, we carry out a multi-criteria sustainability assessment of large-scale bioenergy crop production throughout the 21st century (300 EJ in 2100) using a global land-use model. Our analysis indicates that large-scale bioenergy production without complementary measures results in negative effects on the following sustainability indicators: deforestation, CO2 emissions from land-use change, nitrogen losses, unsustainable water withdrawals and food prices. One of our main findings is that single-sector environmental protection measures next to large-scale bioenergy production are prone to involve trade-offs among these sustainability indicators—at least in the absence of more efficient land or water resource use. For instance, if bioenergy production is accompanied by forest protection, deforestation and associated emissions (SDGs 13 and 15) decline substantially whereas food prices (SDG 2) increase. However, our study also shows that this trade-off strongly depends on the development of future food demand. In contrast to environmental protection measures, we find that agricultural intensification lowers some side-effects of bioenergy production substantially (SDGs 13 and 15) without generating new trade-offs—at least among the sustainability indicators considered here. Moreover, our results indicate that a combination of forest and water protection schemes, improved fertilization efficiency, and agricultural intensification would reduce the side-effects of bioenergy production most comprehensively. However, although our study includes more sustainability indicators than previous studies on bioenergy side-effects, our study represents only a small subset of all indicators relevant for the

Large-scale motions in the universe: a review

International Nuclear Information System (INIS)

Burstein, D.

1990-01-01

The expansion of the universe can be retarded in localised regions within the universe both by the presence of gravity and by non-gravitational motions generated in the post-recombination universe. The motions of galaxies thus generated are called 'peculiar motions', and the amplitudes, size scales and coherence of these peculiar motions are among the most direct records of the structure of the universe. As such, measurements of these properties of the present-day universe provide some of the severest tests of cosmological theories. This is a review of the current evidence for large-scale motions of galaxies out to a distance of ∼5000 km s -1 (in an expanding universe, distance is proportional to radial velocity). 'Large-scale' in this context refers to motions that are correlated over size scales larger than the typical sizes of groups of galaxies, up to and including the size of the volume surveyed. To orient the reader into this relatively new field of study, a short modern history is given together with an explanation of the terminology. Careful consideration is given to the data used to measure the distances, and hence the peculiar motions, of galaxies. The evidence for large-scale motions is presented in a graphical fashion, using only the most reliable data for galaxies spanning a wide range in optical properties and over the complete range of galactic environments. The kinds of systematic errors that can affect this analysis are discussed, and the reliability of these motions is assessed. The predictions of two models of large-scale motion are compared to the observations, and special emphasis is placed on those motions in which our own Galaxy directly partakes. (author)

Pro website development and operations streamlining DevOps for large-scale websites

CERN Document Server

Sacks, Matthew

2012-01-01

Pro Website Development and Operations gives you the experience you need to create and operate a large-scale production website. Large-scale websites have their own unique set of problems regarding their design-problems that can get worse when agile methodologies are adopted for rapid results. Managing large-scale websites, deploying applications, and ensuring they are performing well often requires a full scale team involving the development and operations sides of the company-two departments that don't always see eye to eye. When departments struggle with each other, it adds unnecessary comp

Performance of Edmonton Frail Scale on frailty assessment: its association with multi-dimensional geriatric conditions assessed with specific screening tools.

Science.gov (United States)

Perna, Simone; Francis, Matthew D'Arcy; Bologna, Chiara; Moncaglieri, Francesca; Riva, Antonella; Morazzoni, Paolo; Allegrini, Pietro; Isu, Antonio; Vigo, Beatrice; Guerriero, Fabio; Rondanelli, Mariangela

2017-01-04

The aim of this study was to evaluate the performance of Edmonton Frail Scale (EFS) on frailty assessment in association with multi-dimensional conditions assessed with specific screening tools and to explore the prevalence of frailty by gender. We enrolled 366 hospitalised patients (women\\men: 251\\115), mean age 81.5 years. The EFS was given to the patients to evaluate their frailty. Then we collected data concerning cognitive status through Mini-Mental State Examination (MMSE), health status (evaluated with the number of diseases), functional independence (Barthel Index and Activities Daily Living; BI, ADL, IADL), use of drugs (counting of drugs taken every day), Mini Nutritional Assessment (MNA), Geriatric Depression Scale (GDS), Skeletal Muscle Index of sarcopenia (SMI), osteoporosis and functionality (Handgrip strength). According with the EFS, the 19.7% of subjects were classified as non frail, 66.4% as apparently vulnerable and 13.9% with severe frailty. The EFS scores were associated with cognition (MMSE: β = 0.980; p nutrition (MNA: β = -0.413; p performance (Handgrip: β = -0.114, p performance tool for stratifying the state of fragility in a group of institutionalized elderly. As matter of facts the EFS has been shown to be associated with several geriatric conditions such independence, drugs assumption, mood, mental, functional and nutritional status.

Decentralized Large-Scale Power Balancing

DEFF Research Database (Denmark)

Halvgaard, Rasmus; Jørgensen, John Bagterp; Poulsen, Niels Kjølstad

2013-01-01

problem is formulated as a centralized large-scale optimization problem but is then decomposed into smaller subproblems that are solved locally by each unit connected to an aggregator. For large-scale systems the method is faster than solving the full problem and can be distributed to include an arbitrary...

Experimental performance evaluation of software defined networking (SDN) based data communication networks for large scale flexi-grid optical networks.

Science.gov (United States)

Zhao, Yongli; He, Ruiying; Chen, Haoran; Zhang, Jie; Ji, Yuefeng; Zheng, Haomian; Lin, Yi; Wang, Xinbo

2014-04-21

Software defined networking (SDN) has become the focus in the current information and communication technology area because of its flexibility and programmability. It has been introduced into various network scenarios, such as datacenter networks, carrier networks, and wireless networks. Optical transport network is also regarded as an important application scenario for SDN, which is adopted as the enabling technology of data communication networks (DCN) instead of general multi-protocol label switching (GMPLS). However, the practical performance of SDN based DCN for large scale optical networks, which is very important for the technology selection in the future optical network deployment, has not been evaluated up to now. In this paper we have built a large scale flexi-grid optical network testbed with 1000 virtual optical transport nodes to evaluate the performance of SDN based DCN, including network scalability, DCN bandwidth limitation, and restoration time. A series of network performance parameters including blocking probability, bandwidth utilization, average lightpath provisioning time, and failure restoration time have been demonstrated under various network environments, such as with different traffic loads and different DCN bandwidths. The demonstration in this work can be taken as a proof for the future network deployment.

Visual Data-Analytics of Large-Scale Parallel Discrete-Event Simulations

Energy Technology Data Exchange (ETDEWEB)

Ross, Caitlin; Carothers, Christopher D.; Mubarak, Misbah; Carns, Philip; Ross, Robert; Li, Jianping Kelvin; Ma, Kwan-Liu

2016-11-13

Parallel discrete-event simulation (PDES) is an important tool in the codesign of extreme-scale systems because PDES provides a cost-effective way to evaluate designs of highperformance computing systems. Optimistic synchronization algorithms for PDES, such as Time Warp, allow events to be processed without global synchronization among the processing elements. A rollback mechanism is provided when events are processed out of timestamp order. Although optimistic synchronization protocols enable the scalability of large-scale PDES, the performance of the simulations must be tuned to reduce the number of rollbacks and provide an improved simulation runtime. To enable efficient large-scale optimistic simulations, one has to gain insight into the factors that affect the rollback behavior and simulation performance. We developed a tool for ROSS model developers that gives them detailed metrics on the performance of their large-scale optimistic simulations at varying levels of simulation granularity. Model developers can use this information for parameter tuning of optimistic simulations in order to achieve better runtime and fewer rollbacks. In this work, we instrument the ROSS optimistic PDES framework to gather detailed statistics about the simulation engine. We have also developed an interactive visualization interface that uses the data collected by the ROSS instrumentation to understand the underlying behavior of the simulation engine. The interface connects real time to virtual time in the simulation and provides the ability to view simulation data at different granularities. We demonstrate the usefulness of our framework by performing a visual analysis of the dragonfly network topology model provided by the CODES simulation framework built on top of ROSS. The instrumentation needs to minimize overhead in order to accurately collect data about the simulation performance. To ensure that the instrumentation does not introduce unnecessary overhead, we perform a

Comparative Analysis of Different Protocols to Manage Large Scale Networks

OpenAIRE

Anil Rao Pimplapure; Dr Jayant Dubey; Prashant Sen

2013-01-01

In recent year the numbers, complexity and size is increased in Large Scale Network. The best example of Large Scale Network is Internet, and recently once are Data-centers in Cloud Environment. In this process, involvement of several management tasks such as traffic monitoring, security and performance optimization is big task for Network Administrator. This research reports study the different protocols i.e. conventional protocols like Simple Network Management Protocol and newly Gossip bas...

Performance Prediction for Large-Scale Nuclear Waste Repositories: Final Report

International Nuclear Information System (INIS)

Glassley, W E; Nitao, J J; Grant, W; Boulos, T N; Gokoffski, M O; Johnson, J W; Kercher, J R; Levatin, J A; Steefel, C I

2001-01-01

The goal of this project was development of a software package capable of utilizing terascale computational platforms for solving subsurface flow and transport problems important for disposal of high level nuclear waste materials, as well as for DOE-complex clean-up and stewardship efforts. We sought to develop a tool that would diminish reliance on abstracted models, and realistically represent the coupling between subsurface fluid flow, thermal effects and chemical reactions that both modify the physical framework of the rock materials and which change the rock mineralogy and chemistry of the migrating fluid. Providing such a capability would enhance realism in models and increase confidence in long-term predictions of performance. Achieving this goal also allows more cost-effective design and execution of monitoring programs needed to evaluate model results. This goal was successfully accomplished through the development of a new simulation tool (NUFT-C). This capability allows high resolution modeling of complex coupled thermal-hydrological-geochemical processes in the saturated and unsaturated zones of the Earth's crust. The code allows consideration of virtually an unlimited number of chemical species and minerals in a multi-phase, non-isothermal environment. Because the code is constructed to utilize the computational power of the tera-scale IBM ASCI computers, simulations that encompass large rock volumes and complex chemical systems can now be done without sacrificing spatial or temporal resolution. The code is capable of doing one-, two-, and three-dimensional simulations, allowing unprecedented evaluation of the evolution of rock properties and mineralogical and chemical change as a function of time. The code has been validated by comparing results of simulations to laboratory-scale experiments, other benchmark codes, field scale experiments, and observations in natural systems. The results of these exercises demonstrate that the physics and chemistry

Automating large-scale reactor systems

International Nuclear Information System (INIS)

Kisner, R.A.

1985-01-01

This paper conveys a philosophy for developing automated large-scale control systems that behave in an integrated, intelligent, flexible manner. Methods for operating large-scale systems under varying degrees of equipment degradation are discussed, and a design approach that separates the effort into phases is suggested. 5 refs., 1 fig

Guidance for Large-scale Implementation of Alternate Wetting and Drying: A Biophysical Suitability Assessment

Science.gov (United States)

Sander, B. O.; Wassmann, R.; Nelson, A.; Palao, L.; Wollenberg, E.; Ishitani, M.

2014-12-01

The alternate wetting and drying (AWD) technology for rice production does not only save 15-30% of irrigation water, it also reduces methane emissions by up to 70%. AWD is defined by periodic drying and re-flooding of a rice field. Due to its high mitigation potential and its simplicity to execute this practice AWD has gained a lot of attention in recent years. The Climate and Clean Air Coalition (CCAC) has put AWD high on its agenda and funds a project to guide implementation of this technology in Vietnam, Bangladesh and Colombia. One crucial activity is a biophysical suitability assessment for AWD in the three countries. For this, we analyzed rainfall and soil data as well as potential evapotranspiration to assess if the water balance allows practicing AWD or if precipitation is too high for rice fields to fall dry. In my talk I will outline key factors for a successful large-scale implementation of AWD with a focus on the biophysical suitability assessment. The seasonal suitability maps that we generated highlight priority areas for AWD implementation and guide policy makers to informed decisions about meaningful investments in infrastructure and extension work.

Large-scale retrieval for medical image analytics: A comprehensive review.

Science.gov (United States)

Li, Zhongyu; Zhang, Xiaofan; Müller, Henning; Zhang, Shaoting

2018-01-01

Over the past decades, medical image analytics was greatly facilitated by the explosion of digital imaging techniques, where huge amounts of medical images were produced with ever-increasing quality and diversity. However, conventional methods for analyzing medical images have achieved limited success, as they are not capable to tackle the huge amount of image data. In this paper, we review state-of-the-art approaches for large-scale medical image analysis, which are mainly based on recent advances in computer vision, machine learning and information retrieval. Specifically, we first present the general pipeline of large-scale retrieval, summarize the challenges/opportunities of medical image analytics on a large-scale. Then, we provide a comprehensive review of algorithms and techniques relevant to major processes in the pipeline, including feature representation, feature indexing, searching, etc. On the basis of existing work, we introduce the evaluation protocols and multiple applications of large-scale medical image retrieval, with a variety of exploratory and diagnostic scenarios. Finally, we discuss future directions of large-scale retrieval, which can further improve the performance of medical image analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Performance assessment of mass flow rate measurement capability in a large scale transient two-phase flow test system

International Nuclear Information System (INIS)

Nalezny, C.L.; Chapman, R.L.; Martinell, J.S.; Riordon, R.P.; Solbrig, C.W.

1979-01-01

Mass flow is an important measured variable in the Loss-of-Fluid Test (LOFT) Program. Large uncertainties in mass flow measurements in the LOFT piping during LOFT coolant experiments requires instrument testing in a transient two-phase flow loop that simulates the geometry of the LOFT piping. To satisfy this need, a transient two-phase flow loop has been designed and built. The load cell weighing system, which provides reference mass flow measurements, has been analyzed to assess its capability to provide the measurements. The analysis consisted of first performing a thermal-hydraulic analysis using RELAP4 to compute mass inventory and pressure fluctuations in the system and mass flow rate at the instrument location. RELAP4 output was used as input to a structural analysis code SAPIV which is used to determine load cell response. The computed load cell response was then smoothed and differentiated to compute mass flow rate from the system. Comparison between computed mass flow rate at the instrument location and mass flow rate from the system computed from the load cell output was used to evaluate mass flow measurement capability of the load cell weighing system. Results of the analysis indicate that the load cell weighing system will provide reference mass flows more accurately than the instruments now in LOFT

Performance on large-scale science tests: Item attributes that may impact achievement scores

Science.gov (United States)

Gordon, Janet Victoria

Significant differences in achievement among ethnic groups persist on the eighth-grade science Washington Assessment of Student Learning (WASL). The WASL measures academic performance in science using both scenario and stand-alone question types. Previous research suggests that presenting target items connected to an authentic context, like scenario question types, can increase science achievement scores especially in underrepresented groups and thus help to close the achievement gap. The purpose of this study was to identify significant differences in performance between gender and ethnic subgroups by question type on the 2005 eighth-grade science WASL. MANOVA and ANOVA were used to examine relationships between gender and ethnic subgroups as independent variables with achievement scores on scenario and stand-alone question types as dependent variables. MANOVA revealed no significant effects for gender, suggesting that the 2005 eighth-grade science WASL was gender neutral. However, there were significant effects for ethnicity. ANOVA revealed significant effects for ethnicity and ethnicity by gender interaction in both question types. Effect sizes were negligible for the ethnicity by gender interaction. Large effect sizes between ethnicities on scenario question types became moderate to small effect sizes on stand-alone question types. This indicates the score advantage the higher performing subgroups had over the lower performing subgroups was not as large on stand-alone question types compared to scenario question types. A further comparison examined performance on multiple-choice items only within both question types. Similar achievement patterns between ethnicities emerged; however, achievement patterns between genders changed in boys' favor. Scenario question types appeared to register differences between ethnic groups to a greater degree than stand-alone question types. These differences may be attributable to individual differences in cognition

Plasma performance and scaling laws in the RFX-mod reversed-field pinch experiment

International Nuclear Information System (INIS)

Innocente, P.; Alfier, A.; Canton, A.; Pasqualotto, R.

2009-01-01

The large range of plasma currents (I p = 0.2-1.6 MA) and feedback-controlled magnetic boundary conditions of the RFX-mod experiment make it well suited to performing scaling studies. The assessment of such scaling, in particular those on temperature and energy confinement, is crucial both for improving the operating reversed-field pinch (RFP) devices and for validating the RFP configuration as a candidate for the future fusion reactors. For such a purpose scaling laws for magnetic fluctuations, temperature and energy confinement have been evaluated in stationary operation. RFX-mod scaling laws have been compared with those obtained from other RFP devices and numerical simulations. The role of the magnetic boundary has been analysed, comparing discharges performed with different active control schemes of the edge radial magnetic field.

The Software Reliability of Large Scale Integration Circuit and Very Large Scale Integration Circuit

OpenAIRE

Artem Ganiyev; Jan Vitasek

2010-01-01

This article describes evaluation method of faultless function of large scale integration circuits (LSI) and very large scale integration circuits (VLSI). In the article there is a comparative analysis of factors which determine faultless of integrated circuits, analysis of already existing methods and model of faultless function evaluation of LSI and VLSI. The main part describes a proposed algorithm and program for analysis of fault rate in LSI and VLSI circuits.

Role of natural analogs in performance assessment of nuclear waste repositories

International Nuclear Information System (INIS)

Sagar, B.; Wittmeyer, G.W.

1995-01-01

Mathematical models of the flow of water and transport of radionuclides in porous media will be used to assess the ability of deep geologic repositories to safely contain nuclear waste. These models must, in some sense, be validated to ensure that they adequately describe the physical processes occurring within the repository and its geologic setting. Inasmuch as the spatial and temporal scales over which these models must be applied in performance assessment are very large, validation of these models against laboratory and small-scale field experiments may be considered inadequate. Natural analogs may provide validation data that are representative of physico-chemical processes that occur over spatial and temporal scales as large or larger than those relevant to repository design. The authors discuss the manner in which natural analog data may be used to increase confidence in performance assessment models and conclude that, while these data may be suitable for testing the basic laws governing flow and transport, there is insufficient control of boundary and initial conditions and forcing functions to permit quantitative validation of complex, spatially distributed flow and transport models. The authors also express their opinion that, for collecting adequate data from natural analogs, resources will have to be devoted to them that are much larger than are devoted to them at present

Using Agent Base Models to Optimize Large Scale Network for Large System Inventories

Science.gov (United States)

Shameldin, Ramez Ahmed; Bowling, Shannon R.

2010-01-01

The aim of this paper is to use Agent Base Models (ABM) to optimize large scale network handling capabilities for large system inventories and to implement strategies for the purpose of reducing capital expenses. The models used in this paper either use computational algorithms or procedure implementations developed by Matlab to simulate agent based models in a principal programming language and mathematical theory using clusters, these clusters work as a high performance computational performance to run the program in parallel computational. In both cases, a model is defined as compilation of a set of structures and processes assumed to underlie the behavior of a network system.

On Matrix Sampling and Imputation of Context Questionnaires with Implications for the Generation of Plausible Values in Large-Scale Assessments

Science.gov (United States)

Kaplan, David; Su, Dan

2016-01-01

This article presents findings on the consequences of matrix sampling of context questionnaires for the generation of plausible values in large-scale assessments. Three studies are conducted. Study 1 uses data from PISA 2012 to examine several different forms of missing data imputation within the chained equations framework: predictive mean…

Metric matters : the performance and organisation of volumetric water control in large-scale irrigation in the North Coast of Peru

NARCIS (Netherlands)

Vos, J.M.C.

2002-01-01

This thesis describes the organisation and performance of two large-scale irrigation systems in the North Coast of Peru. Good water management is important in this area because water is scarce and irrigated agriculture provides a livelihood to many small and middle-sized farmers. Water in

Large-scale hydrogen production using nuclear reactors

Energy Technology Data Exchange (ETDEWEB)

Ryland, D.; Stolberg, L.; Kettner, A.; Gnanapragasam, N.; Suppiah, S. [Atomic Energy of Canada Limited, Chalk River, ON (Canada)

2014-07-01

For many years, Atomic Energy of Canada Limited (AECL) has been studying the feasibility of using nuclear reactors, such as the Supercritical Water-cooled Reactor, as an energy source for large scale hydrogen production processes such as High Temperature Steam Electrolysis and the Copper-Chlorine thermochemical cycle. Recent progress includes the augmentation of AECL's experimental capabilities by the construction of experimental systems to test high temperature steam electrolysis button cells at ambient pressure and temperatures up to 850{sup o}C and CuCl/HCl electrolysis cells at pressures up to 7 bar and temperatures up to 100{sup o}C. In parallel, detailed models of solid oxide electrolysis cells and the CuCl/HCl electrolysis cell are being refined and validated using experimental data. Process models are also under development to assess options for economic integration of these hydrogen production processes with nuclear reactors. Options for large-scale energy storage, including hydrogen storage, are also under study. (author)

Preliminary design study of a large scale graphite oxidation loop

International Nuclear Information System (INIS)

Epel, L.G.; Majeski, S.J.; Schweitzer, D.G.; Sheehan, T.V.

1979-08-01

A preliminary design study of a large scale graphite oxidation loop was performed in order to assess feasibility and to estimate capital costs. The nominal design operates at 50 atmospheres helium and 1800 F with a graphite specimen 30 inches long and 10 inches in diameter. It was determined that a simple single walled design was not practical at this time because of a lack of commercially available thick walled high temperature alloys. Two alternative concepts, at reduced operating pressure, were investigated. Both were found to be readily fabricable to operate at 1800 F and capital cost estimates for these are included. A design concept, which is outside the scope of this study, was briefly considered

Application of plant metabonomics in quality assessment for large-scale production of traditional Chinese medicine.

Science.gov (United States)

Ning, Zhangchi; Lu, Cheng; Zhang, Yuxin; Zhao, Siyu; Liu, Baoqin; Xu, Xuegong; Liu, Yuanyan

2013-07-01

The curative effects of traditional Chinese medicines are principally based on the synergic effect of their multi-targeting, multi-ingredient preparations, in contrast to modern pharmacology and drug development that often focus on a single chemical entity. Therefore, the method employing a few markers or pharmacologically active constituents to assess the quality and authenticity of the complex preparations has a number of severe challenges. Metabonomics can provide an effective platform for complex sample analysis. It is also reported to be applied to the quality analysis of the traditional Chinese medicine. Metabonomics enables comprehensive assessment of complex traditional Chinese medicines or herbal remedies and sample classification of diverse biological statuses, origins, or qualities in samples, by means of chemometrics. Identification, processing, and pharmaceutical preparation are the main procedures in the large-scale production of Chinese medicinal preparations. Through complete scans, plants metabonomics addresses some of the shortfalls of single analyses and presents a considerable potential to become a sharp tool for traditional Chinese medicine quality assessment. Georg Thieme Verlag KG Stuttgart · New York.

Large scale debris-flow hazard assessment: a geotechnical approach and GIS modelling

Directory of Open Access Journals (Sweden)

G. Delmonaco

2003-01-01

Full Text Available A deterministic distributed model has been developed for large-scale debris-flow hazard analysis in the basin of River Vezza (Tuscany Region – Italy. This area (51.6 km 2 was affected by over 250 landslides. These were classified as debris/earth flow mainly involving the metamorphic geological formations outcropping in the area, triggered by the pluviometric event of 19 June 1996. In the last decades landslide hazard and risk analysis have been favoured by the development of GIS techniques permitting the generalisation, synthesis and modelling of stability conditions on a large scale investigation (>1:10 000. In this work, the main results derived by the application of a geotechnical model coupled with a hydrological model for the assessment of debris flows hazard analysis, are reported. This analysis has been developed starting by the following steps: landslide inventory map derived by aerial photo interpretation, direct field survey, generation of a database and digital maps, elaboration of a DTM and derived themes (i.e. slope angle map, definition of a superficial soil thickness map, geotechnical soil characterisation through implementation of a backanalysis on test slopes, laboratory test analysis, inference of the influence of precipitation, for distinct return times, on ponding time and pore pressure generation, implementation of a slope stability model (infinite slope model and generalisation of the safety factor for estimated rainfall events with different return times. Such an approach has allowed the identification of potential source areas of debris flow triggering. This is used to detected precipitation events with estimated return time of 10, 50, 75 and 100 years. The model shows a dramatic decrease of safety conditions for the simulation when is related to a 75 years return time rainfall event. It corresponds to an estimated cumulated daily intensity of 280–330 mm. This value can be considered the hydrological triggering

Large-scale exact diagonalizations reveal low-momentum scales of nuclei

Science.gov (United States)

Forssén, C.; Carlsson, B. D.; Johansson, H. T.; Sääf, D.; Bansal, A.; Hagen, G.; Papenbrock, T.

2018-03-01

Ab initio methods aim to solve the nuclear many-body problem with controlled approximations. Virtually exact numerical solutions for realistic interactions can only be obtained for certain special cases such as few-nucleon systems. Here we extend the reach of exact diagonalization methods to handle model spaces with dimension exceeding 1010 on a single compute node. This allows us to perform no-core shell model (NCSM) calculations for 6Li in model spaces up to Nmax=22 and to reveal the 4He+d halo structure of this nucleus. Still, the use of a finite harmonic-oscillator basis implies truncations in both infrared (IR) and ultraviolet (UV) length scales. These truncations impose finite-size corrections on observables computed in this basis. We perform IR extrapolations of energies and radii computed in the NCSM and with the coupled-cluster method at several fixed UV cutoffs. It is shown that this strategy enables information gain also from data that is not fully UV converged. IR extrapolations improve the accuracy of relevant bound-state observables for a range of UV cutoffs, thus making them profitable tools. We relate the momentum scale that governs the exponential IR convergence to the threshold energy for the first open decay channel. Using large-scale NCSM calculations we numerically verify this small-momentum scale of finite nuclei.

Phylogenetic distribution of large-scale genome patchiness

Directory of Open Access Journals (Sweden)

Hackenberg Michael

2008-04-01

Full Text Available Abstract Background The phylogenetic distribution of large-scale genome structure (i.e. mosaic compositional patchiness has been explored mainly by analytical ultracentrifugation of bulk DNA. However, with the availability of large, good-quality chromosome sequences, and the recently developed computational methods to directly analyze patchiness on the genome sequence, an evolutionary comparative analysis can be carried out at the sequence level. Results The local variations in the scaling exponent of the Detrended Fluctuation Analysis are used here to analyze large-scale genome structure and directly uncover the characteristic scales present in genome sequences. Furthermore, through shuffling experiments of selected genome regions, computationally-identified, isochore-like regions were identified as the biological source for the uncovered large-scale genome structure. The phylogenetic distribution of short- and large-scale patchiness was determined in the best-sequenced genome assemblies from eleven eukaryotic genomes: mammals (Homo sapiens, Pan troglodytes, Mus musculus, Rattus norvegicus, and Canis familiaris, birds (Gallus gallus, fishes (Danio rerio, invertebrates (Drosophila melanogaster and Caenorhabditis elegans, plants (Arabidopsis thaliana and yeasts (Saccharomyces cerevisiae. We found large-scale patchiness of genome structure, associated with in silico determined, isochore-like regions, throughout this wide phylogenetic range. Conclusion Large-scale genome structure is detected by directly analyzing DNA sequences in a wide range of eukaryotic chromosome sequences, from human to yeast. In all these genomes, large-scale patchiness can be associated with the isochore-like regions, as directly detected in silico at the sequence level.

Managing large-scale models: DBS

International Nuclear Information System (INIS)

1981-05-01

A set of fundamental management tools for developing and operating a large scale model and data base system is presented. Based on experience in operating and developing a large scale computerized system, the only reasonable way to gain strong management control of such a system is to implement appropriate controls and procedures. Chapter I discusses the purpose of the book. Chapter II classifies a broad range of generic management problems into three groups: documentation, operations, and maintenance. First, system problems are identified then solutions for gaining management control are disucssed. Chapters III, IV, and V present practical methods for dealing with these problems. These methods were developed for managing SEAS but have general application for large scale models and data bases

Detecting differential protein expression in large-scale population proteomics

Energy Technology Data Exchange (ETDEWEB)

Ryu, Soyoung; Qian, Weijun; Camp, David G.; Smith, Richard D.; Tompkins, Ronald G.; Davis, Ronald W.; Xiao, Wenzhong

2014-06-17

Mass spectrometry-based high-throughput quantitative proteomics shows great potential in clinical biomarker studies, identifying and quantifying thousands of proteins in biological samples. However, methods are needed to appropriately handle issues/challenges unique to mass spectrometry data in order to detect as many biomarker proteins as possible. One issue is that different mass spectrometry experiments generate quite different total numbers of quantified peptides, which can result in more missing peptide abundances in an experiment with a smaller total number of quantified peptides. Another issue is that the quantification of peptides is sometimes absent, especially for less abundant peptides and such missing values contain the information about the peptide abundance. Here, we propose a Significance Analysis for Large-scale Proteomics Studies (SALPS) that handles missing peptide intensity values caused by the two mechanisms mentioned above. Our model has a robust performance in both simulated data and proteomics data from a large clinical study. Because varying patients’ sample qualities and deviating instrument performances are not avoidable for clinical studies performed over the course of several years, we believe that our approach will be useful to analyze large-scale clinical proteomics data.

Evaluation of psychometric properties of Tinetti performance-oriented mobility assessment scale in subjects with knee osteoarthritis

OpenAIRE

Parveen, Huma; Noohu, Majumi M.

2017-01-01

Objective: The objective of this study was to determine the psychometric properties of the Tinetti Performance-Oriented Mobility Assessment (POMA) scale to measure balance and gait impairments in individuals with knee osteoarthritis (OA). Methods: A convenient sample of 25 individuals with bilateral OA knee were recruited. The convergent validity was determined by correlation analysis between scores of Berg Balance Scale (BBS) with balance subscale (POMA-B) and the Timed Up and Go Test (TU...

Large Scale Self-Organizing Information Distribution System

National Research Council Canada - National Science Library

Low, Steven

2005-01-01

This project investigates issues in "large-scale" networks. Here "large-scale" refers to networks with large number of high capacity nodes and transmission links, and shared by a large number of users...

A new scaling methodology for NO(x) emissions performance of gas burners and furnaces

Science.gov (United States)

Hsieh, Tse-Chih

1997-11-01

A general burner and furnace scaling methodology is presented, together with the resulting scaling model for NOsb{x} emissions performance of a broad class of swirl-stabilized industrial gas burners. The model is based on results from a set of novel burner scaling experiments on a generic gas burner and furnace design at five different scales having near-uniform geometric, aerodynamic, and thermal similarity and uniform measurement protocols. These provide the first NOsb{x} scaling data over the range of thermal scales from 30 kW to 12 MW, including input-output measurements as well as detailed in-flame measurements of NO, NOsb{x}, CO, Osb2, unburned hydrocarbons, temperature, and velocities at each scale. The in-flame measurements allow identification of key sources of NOsb{x} production. The underlying physics of these NOsb{x} sources lead to scaling laws for their respective contributions to the overall NOsb{x} emissions performance. It is found that the relative importance of each source depends on the burner scale and operating conditions. Simple furnace residence time scaling is shown to be largely irrelevant, with NOsb{x} emissions instead being largely controlled by scaling of the near-burner region. The scalings for these NOsb{x} sources are combined in a comprehensive scaling model for NOsb{x} emission performance. Results from the scaling model show good agreement with experimental data at all burner scales and over the entire range of turndown, staging, preheat, and excess air dilution, with correlations generally exceeding 90%. The scaling model permits design trade-off assessments for a broad class of burners and furnaces, and allows performance of full industrial scale burners and furnaces of this type to be inferred from results of small scale tests.

Application of parallel computing techniques to a large-scale reservoir simulation

International Nuclear Information System (INIS)

Zhang, Keni; Wu, Yu-Shu; Ding, Chris; Pruess, Karsten

2001-01-01

Even with the continual advances made in both computational algorithms and computer hardware used in reservoir modeling studies, large-scale simulation of fluid and heat flow in heterogeneous reservoirs remains a challenge. The problem commonly arises from intensive computational requirement for detailed modeling investigations of real-world reservoirs. This paper presents the application of a massive parallel-computing version of the TOUGH2 code developed for performing large-scale field simulations. As an application example, the parallelized TOUGH2 code is applied to develop a three-dimensional unsaturated-zone numerical model simulating flow of moisture, gas, and heat in the unsaturated zone of Yucca Mountain, Nevada, a potential repository for high-level radioactive waste. The modeling approach employs refined spatial discretization to represent the heterogeneous fractured tuffs of the system, using more than a million 3-D gridblocks. The problem of two-phase flow and heat transfer within the model domain leads to a total of 3,226,566 linear equations to be solved per Newton iteration. The simulation is conducted on a Cray T3E-900, a distributed-memory massively parallel computer. Simulation results indicate that the parallel computing technique, as implemented in the TOUGH2 code, is very efficient. The reliability and accuracy of the model results have been demonstrated by comparing them to those of small-scale (coarse-grid) models. These comparisons show that simulation results obtained with the refined grid provide more detailed predictions of the future flow conditions at the site, aiding in the assessment of proposed repository performance

Methods for assessing the socioeconomic impacts of large-scale resource developments: implications for nuclear repository siting

International Nuclear Information System (INIS)

Murdock, S.H.; Leistritz, F.L.

1983-03-01

An overview of the major methods presently available for assessing the socioeconomic impacts of large-scale resource developments and includes discussion of the implications and applications of such methods for nuclear-waste-repository siting are provided. The report: (1) summarizes conceptual approaches underlying, and methodological alternatives for, the conduct of impact assessments in each substantive area, and then enumerates advantages and disadvantages of each alternative; (2) describes factors related to the impact-assessment process, impact events, and the characteristics of rural areas that affect the magnitude and distribution of impacts and the assessment of impacts in each area; (3) provides a detailed review of those methodologies actually used in impact assessment for each area, describes advantages and problems encountered in the use of each method, and identifies the frequency of use and the general level of acceptance of each technique; and (4) summarizes the implications of each area of projection for the repository-siting process, the applicability of the methods for each area to the special and standard features of repositories, and makes general recommendations concerning specific methods and procedures that should be incorporated in assessments for siting areas

Galaxies distribution in the universe: large-scale statistics and structures

International Nuclear Information System (INIS)

Maurogordato, Sophie

1988-01-01

This research thesis addresses the distribution of galaxies in the Universe, and more particularly large scale statistics and structures. Based on an assessment of the main used statistical techniques, the author outlines the need to develop additional tools to correlation functions in order to characterise the distribution. She introduces a new indicator: the probability of a volume randomly tested in the distribution to be void. This allows a characterisation of void properties at the work scales (until 10h"-"1 Mpc) in the Harvard Smithsonian Center for Astrophysics Redshift Survey, or CfA catalog. A systematic analysis of statistical properties of different sub-samples has then been performed with respect to the size and location, luminosity class, and morphological type. This analysis is then extended to different scenarios of structure formation. A program of radial speed measurements based on observations allows the determination of possible relationships between apparent structures. The author also presents results of the search for south extensions of Perseus supernova [fr

A large scale field experiment in the Amazon Basin (Lambada/Bateristca)

Energy Technology Data Exchange (ETDEWEB)

Dolman, A.J.; Kabat, P.; Gash, J.H.C.; Noilhan, J.; Jochum, A.M.; Nobre, C. [Winand Staring Centre, Wageningen (Netherlands)

1994-12-31

A description is given of a large scale field experiment planned in the Amazon Basin, aiming to assess the large scale balances of energy, water and CO{sub 2}. The background for this experiment, the embedding in global change programmes of IGBP/BAHC and WCRP/GEWEX is described. A proposal by four European groups aimed at designing the experiment with the help of mesoscale models is described and a possible European input to this experiment is suggested. 24 refs., 1 app.

Large scale structure and baryogenesis

International Nuclear Information System (INIS)

Kirilova, D.P.; Chizhov, M.V.

2001-08-01

We discuss a possible connection between the large scale structure formation and the baryogenesis in the universe. An update review of the observational indications for the presence of a very large scale 120h -1 Mpc in the distribution of the visible matter of the universe is provided. The possibility to generate a periodic distribution with the characteristic scale 120h -1 Mpc through a mechanism producing quasi-periodic baryon density perturbations during inflationary stage, is discussed. The evolution of the baryon charge density distribution is explored in the framework of a low temperature boson condensate baryogenesis scenario. Both the observed very large scale of a the visible matter distribution in the universe and the observed baryon asymmetry value could naturally appear as a result of the evolution of a complex scalar field condensate, formed at the inflationary stage. Moreover, for some model's parameters a natural separation of matter superclusters from antimatter ones can be achieved. (author)

Creating Large Scale Database Servers

International Nuclear Information System (INIS)

Becla, Jacek

2001-01-01

The BaBar experiment at the Stanford Linear Accelerator Center (SLAC) is designed to perform a high precision investigation of the decays of the B-meson produced from electron-positron interactions. The experiment, started in May 1999, will generate approximately 300TB/year of data for 10 years. All of the data will reside in Objectivity databases accessible via the Advanced Multi-threaded Server (AMS). To date, over 70TB of data have been placed in Objectivity/DB, making it one of the largest databases in the world. Providing access to such a large quantity of data through a database server is a daunting task. A full-scale testbed environment had to be developed to tune various software parameters and a fundamental change had to occur in the AMS architecture to allow it to scale past several hundred terabytes of data. Additionally, several protocol extensions had to be implemented to provide practical access to large quantities of data. This paper will describe the design of the database and the changes that we needed to make in the AMS for scalability reasons and how the lessons we learned would be applicable to virtually any kind of database server seeking to operate in the Petabyte region

Creating Large Scale Database Servers

Energy Technology Data Exchange (ETDEWEB)

Becla, Jacek

2001-12-14

The BaBar experiment at the Stanford Linear Accelerator Center (SLAC) is designed to perform a high precision investigation of the decays of the B-meson produced from electron-positron interactions. The experiment, started in May 1999, will generate approximately 300TB/year of data for 10 years. All of the data will reside in Objectivity databases accessible via the Advanced Multi-threaded Server (AMS). To date, over 70TB of data have been placed in Objectivity/DB, making it one of the largest databases in the world. Providing access to such a large quantity of data through a database server is a daunting task. A full-scale testbed environment had to be developed to tune various software parameters and a fundamental change had to occur in the AMS architecture to allow it to scale past several hundred terabytes of data. Additionally, several protocol extensions had to be implemented to provide practical access to large quantities of data. This paper will describe the design of the database and the changes that we needed to make in the AMS for scalability reasons and how the lessons we learned would be applicable to virtually any kind of database server seeking to operate in the Petabyte region.

Automatic management software for large-scale cluster system

International Nuclear Information System (INIS)

Weng Yunjian; Chinese Academy of Sciences, Beijing; Sun Gongxing

2007-01-01

At present, the large-scale cluster system faces to the difficult management. For example the manager has large work load. It needs to cost much time on the management and the maintenance of large-scale cluster system. The nodes in large-scale cluster system are very easy to be chaotic. Thousands of nodes are put in big rooms so that some managers are very easy to make the confusion with machines. How do effectively carry on accurate management under the large-scale cluster system? The article introduces ELFms in the large-scale cluster system. Furthermore, it is proposed to realize the large-scale cluster system automatic management. (authors)

A probabilistic assessment of large scale wind power development for long-term energy resource planning

Science.gov (United States)

Kennedy, Scott Warren

A steady decline in the cost of wind turbines and increased experience in their successful operation have brought this technology to the forefront of viable alternatives for large-scale power generation. Methodologies for understanding the costs and benefits of large-scale wind power development, however, are currently limited. In this thesis, a new and widely applicable technique for estimating the social benefit of large-scale wind power production is presented. The social benefit is based upon wind power's energy and capacity services and the avoidance of environmental damages. The approach uses probabilistic modeling techniques to account for the stochastic interaction between wind power availability, electricity demand, and conventional generator dispatch. A method for including the spatial smoothing effect of geographically dispersed wind farms is also introduced. The model has been used to analyze potential offshore wind power development to the south of Long Island, NY. If natural gas combined cycle (NGCC) and integrated gasifier combined cycle (IGCC) are the alternative generation sources, wind power exhibits a negative social benefit due to its high capacity cost and the relatively low emissions of these advanced fossil-fuel technologies. Environmental benefits increase significantly if charges for CO2 emissions are included. Results also reveal a diminishing social benefit as wind power penetration increases. The dependence of wind power benefits on natural gas and coal prices is also discussed. In power systems with a high penetration of wind generated electricity, the intermittent availability of wind power may influence hourly spot prices. A price responsive electricity demand model is introduced that shows a small increase in wind power value when consumers react to hourly spot prices. The effectiveness of this mechanism depends heavily on estimates of the own- and cross-price elasticities of aggregate electricity demand. This work makes a valuable

Integrating adaptive behaviour in large-scale flood risk assessments: an Agent-Based Modelling approach

Science.gov (United States)

Haer, Toon; Aerts, Jeroen

2015-04-01

Between 1998 and 2009, Europe suffered over 213 major damaging floods, causing 1126 deaths, displacing around half a million people. In this period, floods caused at least 52 billion euro in insured economic losses making floods the most costly natural hazard faced in Europe. In many low-lying areas, the main strategy to cope with floods is to reduce the risk of the hazard through flood defence structures, like dikes and levees. However, it is suggested that part of the responsibility for flood protection needs to shift to households and businesses in areas at risk, and that governments and insurers can effectively stimulate the implementation of individual protective measures. However, adaptive behaviour towards flood risk reduction and the interaction between the government, insurers, and individuals has hardly been studied in large-scale flood risk assessments. In this study, an European Agent-Based Model is developed including agent representatives for the administrative stakeholders of European Member states, insurers and reinsurers markets, and individuals following complex behaviour models. The Agent-Based Modelling approach allows for an in-depth analysis of the interaction between heterogeneous autonomous agents and the resulting (non-)adaptive behaviour. Existing flood damage models are part of the European Agent-Based Model to allow for a dynamic response of both the agents and the environment to changing flood risk and protective efforts. By following an Agent-Based Modelling approach this study is a first contribution to overcome the limitations of traditional large-scale flood risk models in which the influence of individual adaptive behaviour towards flood risk reduction is often lacking.

Concepts for Large Scale Hydrogen Production

OpenAIRE

Jakobsen, Daniel; Åtland, Vegar

2016-01-01

The objective of this thesis is to perform a techno-economic analysis of large-scale, carbon-lean hydrogen production in Norway, in order to evaluate various production methods and estimate a breakeven price level. Norway possesses vast energy resources and the export of oil and gas is vital to the country s economy. The results of this thesis indicate that hydrogen represents a viable, carbon-lean opportunity to utilize these resources, which can prove key in the future of Norwegian energy e...

The assessment of the readiness of five countries to implement child maltreatment prevention programs on a large scale.

Science.gov (United States)

Mikton, Christopher; Power, Mick; Raleva, Marija; Makoae, Mokhantso; Al Eissa, Majid; Cheah, Irene; Cardia, Nancy; Choo, Claire; Almuneef, Maha

2013-12-01

This study aimed to systematically assess the readiness of five countries - Brazil, the Former Yugoslav Republic of Macedonia, Malaysia, Saudi Arabia, and South Africa - to implement evidence-based child maltreatment prevention programs on a large scale. To this end, it applied a recently developed method called Readiness Assessment for the Prevention of Child Maltreatment based on two parallel 100-item instruments. The first measures the knowledge, attitudes, and beliefs concerning child maltreatment prevention of key informants; the second, completed by child maltreatment prevention experts using all available data in the country, produces a more objective assessment readiness. The instruments cover all of the main aspects of readiness including, for instance, availability of scientific data on the problem, legislation and policies, will to address the problem, and material resources. Key informant scores ranged from 31.2 (Brazil) to 45.8/100 (the Former Yugoslav Republic of Macedonia) and expert scores, from 35.2 (Brazil) to 56/100 (Malaysia). Major gaps identified in almost all countries included a lack of professionals with the skills, knowledge, and expertise to implement evidence-based child maltreatment programs and of institutions to train them; inadequate funding, infrastructure, and equipment; extreme rarity of outcome evaluations of prevention programs; and lack of national prevalence surveys of child maltreatment. In sum, the five countries are in a low to moderate state of readiness to implement evidence-based child maltreatment prevention programs on a large scale. Such an assessment of readiness - the first of its kind - allows gaps to be identified and then addressed to increase the likelihood of program success. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sampling strategy for a large scale indoor radiation survey - a pilot project

International Nuclear Information System (INIS)

Strand, T.; Stranden, E.

1986-01-01

Optimisation of a stratified random sampling strategy for large scale indoor radiation surveys is discussed. It is based on the results from a small scale pilot project where variances in dose rates within different categories of houses were assessed. By selecting a predetermined precision level for the mean dose rate in a given region, the number of measurements needed can be optimised. The results of a pilot project in Norway are presented together with the development of the final sampling strategy for a planned large scale survey. (author)

Large-scale ground motion simulation using GPGPU

Science.gov (United States)

Aoi, S.; Maeda, T.; Nishizawa, N.; Aoki, T.

2012-12-01

Huge computation resources are required to perform large-scale ground motion simulations using 3-D finite difference method (FDM) for realistic and complex models with high accuracy. Furthermore, thousands of various simulations are necessary to evaluate the variability of the assessment caused by uncertainty of the assumptions of the source models for future earthquakes. To conquer the problem of restricted computational resources, we introduced the use of GPGPU (General purpose computing on graphics processing units) which is the technique of using a GPU as an accelerator of the computation which has been traditionally conducted by the CPU. We employed the CPU version of GMS (Ground motion Simulator; Aoi et al., 2004) as the original code and implemented the function for GPU calculation using CUDA (Compute Unified Device Architecture). GMS is a total system for seismic wave propagation simulation based on 3-D FDM scheme using discontinuous grids (Aoi&Fujiwara, 1999), which includes the solver as well as the preprocessor tools (parameter generation tool) and postprocessor tools (filter tool, visualization tool, and so on). The computational model is decomposed in two horizontal directions and each decomposed model is allocated to a different GPU. We evaluated the performance of our newly developed GPU version of GMS on the TSUBAME2.0 which is one of the Japanese fastest supercomputer operated by the Tokyo Institute of Technology. First we have performed a strong scaling test using the model with about 22 million grids and achieved 3.2 and 7.3 times of the speed-up by using 4 and 16 GPUs. Next, we have examined a weak scaling test where the model sizes (number of grids) are increased in proportion to the degree of parallelism (number of GPUs). The result showed almost perfect linearity up to the simulation with 22 billion grids using 1024 GPUs where the calculation speed reached to 79.7 TFlops and about 34 times faster than the CPU calculation using the same number

Methods for large-scale international studies on ICT in education

NARCIS (Netherlands)

Pelgrum, W.J.; Plomp, T.; Voogt, Joke; Knezek, G.A.

2008-01-01

International comparative assessment is a research method applied for describing and analyzing educational processes and outcomes. They are used to ‘describe the status quo’ in educational systems from an international comparative perspective. This chapter reviews different large scale international

Hybrid Reynolds-Averaged/Large Eddy Simulation of a Cavity Flameholder; Assessment of Modeling Sensitivities

Science.gov (United States)

Baurle, R. A.

2015-01-01

Steady-state and scale-resolving simulations have been performed for flow in and around a model scramjet combustor flameholder. The cases simulated corresponded to those used to examine this flowfield experimentally using particle image velocimetry. A variety of turbulence models were used for the steady-state Reynolds-averaged simulations which included both linear and non-linear eddy viscosity models. The scale-resolving simulations used a hybrid Reynolds-averaged / large eddy simulation strategy that is designed to be a large eddy simulation everywhere except in the inner portion (log layer and below) of the boundary layer. Hence, this formulation can be regarded as a wall-modeled large eddy simulation. This effort was undertaken to formally assess the performance of the hybrid Reynolds-averaged / large eddy simulation modeling approach in a flowfield of interest to the scramjet research community. The numerical errors were quantified for both the steady-state and scale-resolving simulations prior to making any claims of predictive accuracy relative to the measurements. The steady-state Reynolds-averaged results showed a high degree of variability when comparing the predictions obtained from each turbulence model, with the non-linear eddy viscosity model (an explicit algebraic stress model) providing the most accurate prediction of the measured values. The hybrid Reynolds-averaged/large eddy simulation results were carefully scrutinized to ensure that even the coarsest grid had an acceptable level of resolution for large eddy simulation, and that the time-averaged statistics were acceptably accurate. The autocorrelation and its Fourier transform were the primary tools used for this assessment. The statistics extracted from the hybrid simulation strategy proved to be more accurate than the Reynolds-averaged results obtained using the linear eddy viscosity models. However, there was no predictive improvement noted over the results obtained from the explicit

Aeroelastic analysis of an offshore wind turbine: Design and Fatigue Performance of Large Utility-Scale Wind Turbine Blades

OpenAIRE

Fossum, Peter Kalsaas

2012-01-01

Aeroelastic design and fatigue analysis of large utility-scale wind turbine blades are performed. The applied fatigue model is based on established methods and is incorporated in an iterative numerical design tool for realistic wind turbine blades. All aerodynamic and structural design properties are available in literature. The software tool FAST is used for advanced aero-servo-elastic load calculations and stress-histories are calculated with elementary beam theory.According to wind energy ...

Large-Scale Outflows in Seyfert Galaxies

Science.gov (United States)

Colbert, E. J. M.; Baum, S. A.

1995-12-01

\\catcode`\\@=11 \\ialign{m @th#1hfil ##hfil \\crcr#2\\crcr\\sim\\crcr}}} \\catcode`\\@=12 Highly collimated outflows extend out to Mpc scales in many radio-loud active galaxies. In Seyfert galaxies, which are radio-quiet, the outflows extend out to kpc scales and do not appear to be as highly collimated. In order to study the nature of large-scale (>~1 kpc) outflows in Seyferts, we have conducted optical, radio and X-ray surveys of a distance-limited sample of 22 edge-on Seyfert galaxies. Results of the optical emission-line imaging and spectroscopic survey imply that large-scale outflows are present in >~{{1} /{4}} of all Seyferts. The radio (VLA) and X-ray (ROSAT) surveys show that large-scale radio and X-ray emission is present at about the same frequency. Kinetic luminosities of the outflows in Seyferts are comparable to those in starburst-driven superwinds. Large-scale radio sources in Seyferts appear diffuse, but do not resemble radio halos found in some edge-on starburst galaxies (e.g. M82). We discuss the feasibility of the outflows being powered by the active nucleus (e.g. a jet) or a circumnuclear starburst.

Assessment of the technology required to develop photovoltaic power system for large scale national energy applications

Science.gov (United States)

Lutwack, R.

1974-01-01

A technical assessment of a program to develop photovoltaic power system technology for large-scale national energy applications was made by analyzing and judging the alternative candidate photovoltaic systems and development tasks. A program plan was constructed based on achieving the 10 year objective of a program to establish the practicability of large-scale terrestrial power installations using photovoltaic conversion arrays costing less than $0.50/peak W. Guidelines for the tasks of a 5 year program were derived from a set of 5 year objectives deduced from the 10 year objective. This report indicates the need for an early emphasis on the development of the single-crystal Si photovoltaic system for commercial utilization; a production goal of 5 x 10 to the 8th power peak W/year of $0.50 cells was projected for the year 1985. The developments of other photovoltaic conversion systems were assigned to longer range development roles. The status of the technology developments and the applicability of solar arrays in particular power installations, ranging from houses to central power plants, was scheduled to be verified in a series of demonstration projects. The budget recommended for the first 5 year phase of the program is $268.5M.

Comparing the performance of SIMD computers by running large air pollution models

DEFF Research Database (Denmark)

Brown, J.; Hansen, Per Christian; Wasniewski, J.

1996-01-01

To compare the performance and use of three massively parallel SIMD computers, we implemented a large air pollution model on these computers. Using a realistic large-scale model, we gained detailed insight about the performance of the computers involved when used to solve large-scale scientific...... problems that involve several types of numerical computations. The computers used in our study are the Connection Machines CM-200 and CM-5, and the MasPar MP-2216...

[A large-scale accident in Alpine terrain].

Science.gov (United States)

Wildner, M; Paal, P

2015-02-01

Due to the geographical conditions, large-scale accidents amounting to mass casualty incidents (MCI) in Alpine terrain regularly present rescue teams with huge challenges. Using an example incident, specific conditions and typical problems associated with such a situation are presented. The first rescue team members to arrive have the elementary tasks of qualified triage and communication to the control room, which is required to dispatch the necessary additional support. Only with a clear "concept", to which all have to adhere, can the subsequent chaos phase be limited. In this respect, a time factor confounded by adverse weather conditions or darkness represents enormous pressure. Additional hazards are frostbite and hypothermia. If priorities can be established in terms of urgency, then treatment and procedure algorithms have proven successful. For evacuation of causalities, a helicopter should be strived for. Due to the low density of hospitals in Alpine regions, it is often necessary to distribute the patients over a wide area. Rescue operations in Alpine terrain have to be performed according to the particular conditions and require rescue teams to have specific knowledge and expertise. The possibility of a large-scale accident should be considered when planning events. With respect to optimization of rescue measures, regular training and exercises are rational, as is the analysis of previous large-scale Alpine accidents.

Exploiting multi-scale parallelism for large scale numerical modelling of laser wakefield accelerators

International Nuclear Information System (INIS)

Fonseca, R A; Vieira, J; Silva, L O; Fiuza, F; Davidson, A; Tsung, F S; Mori, W B

2013-01-01

A new generation of laser wakefield accelerators (LWFA), supported by the extreme accelerating fields generated in the interaction of PW-Class lasers and underdense targets, promises the production of high quality electron beams in short distances for multiple applications. Achieving this goal will rely heavily on numerical modelling to further understand the underlying physics and identify optimal regimes, but large scale modelling of these scenarios is computationally heavy and requires the efficient use of state-of-the-art petascale supercomputing systems. We discuss the main difficulties involved in running these simulations and the new developments implemented in the OSIRIS framework to address these issues, ranging from multi-dimensional dynamic load balancing and hybrid distributed/shared memory parallelism to the vectorization of the PIC algorithm. We present the results of the OASCR Joule Metric program on the issue of large scale modelling of LWFA, demonstrating speedups of over 1 order of magnitude on the same hardware. Finally, scalability to over ∼10 6 cores and sustained performance over ∼2 P Flops is demonstrated, opening the way for large scale modelling of LWFA scenarios. (paper)

SCALE INTERACTION IN A MIXING LAYER. THE ROLE OF THE LARGE-SCALE GRADIENTS

KAUST Repository

Fiscaletti, Daniele

2015-08-23

The interaction between scales is investigated in a turbulent mixing layer. The large-scale amplitude modulation of the small scales already observed in other works depends on the crosswise location. Large-scale positive fluctuations correlate with a stronger activity of the small scales on the low speed-side of the mixing layer, and a reduced activity on the high speed-side. However, from physical considerations we would expect the scales to interact in a qualitatively similar way within the flow and across different turbulent flows. Therefore, instead of the large-scale fluctuations, the large-scale gradients modulation of the small scales has been additionally investigated.

Coupled Large Scale Hydro-mechanical Modelling for cap-rock Failure Risk Assessment of CO2 Storage in Deep Saline Aquifers

International Nuclear Information System (INIS)

Rohmer, J.; Seyedi, D.M.

2010-01-01

This work presents a numerical strategy of large scale hydro-mechanical simulations to assess the risk of damage in cap-rock formations during a CO 2 injection process. The proposed methodology is based on the development of a sequential coupling between a multiphase fluid flow (TOUGH2) and a hydro-mechanical calculation code (Code-Aster) that enables us to perform coupled hydro-mechanical simulation at a regional scale. The likelihood of different cap-rock damage mechanisms can then be evaluated based on the results of the coupled simulations. A scenario based approach is proposed to take into account the effect of the uncertainty of model parameters on damage likelihood. The developed methodology is applied for the cap-rock failure analysis of deep aquifer of the Dogger formation in the context of the Paris basin multilayered geological system as a demonstration example. The simulation is carried out at a regional scale (100 km) considering an industrial mass injection rate of CO 2 of 10 Mt/y. The assessment of the stress state after 10 years of injection is conducted through the developed sequential coupling. Two failure mechanisms have been taken into account, namely the tensile fracturing and the shear slip reactivation of pre-existing fractures. To deal with the large uncertainties due to sparse data on the layer formations, a scenario based strategy is undertaken. It consists in defining a first reference modelling scenario considering the mean values of the hydro-mechanical properties for each layer. A sensitivity analysis is then carried out and shows the importance of both the initial stress state and the reservoir hydraulic properties on the cap-rock failure tendency. On this basis, a second scenario denoted 'critical' is defined so that the most influential model parameters are taken in their worst configuration. None of these failure criteria is activated for the considered conditions. At a phenomenological level, this study points out three key

Dissecting the large-scale galactic conformity

Science.gov (United States)

Seo, Seongu

2018-01-01

Galactic conformity is an observed phenomenon that galaxies located in the same region have similar properties such as star formation rate, color, gas fraction, and so on. The conformity was first observed among galaxies within in the same halos (“one-halo conformity”). The one-halo conformity can be readily explained by mutual interactions among galaxies within a halo. Recent observations however further witnessed a puzzling connection among galaxies with no direct interaction. In particular, galaxies located within a sphere of ~5 Mpc radius tend to show similarities, even though the galaxies do not share common halos with each other ("two-halo conformity" or “large-scale conformity”). Using a cosmological hydrodynamic simulation, Illustris, we investigate the physical origin of the two-halo conformity and put forward two scenarios. First, back-splash galaxies are likely responsible for the large-scale conformity. They have evolved into red galaxies due to ram-pressure stripping in a given galaxy cluster and happen to reside now within a ~5 Mpc sphere. Second, galaxies in strong tidal field induced by large-scale structure also seem to give rise to the large-scale conformity. The strong tides suppress star formation in the galaxies. We discuss the importance of the large-scale conformity in the context of galaxy evolution.

Metric matters : the performance and organisation of volumetric water control in large-scale irrigation in the North Coast of Peru

OpenAIRE

Vos, J.M.C.

2002-01-01

This thesis describes the organisation and performance of two large-scale irrigation systems in the North Coast of Peru. Good water management is important in this area because water is scarce and irrigated agriculture provides a livelihood to many small and middle-sized farmers. Water in the coast of Peru is considered to be badly managed, however this study shows that performance is more optimal than critics assume. Apart from the relevance in the local water management discussion,...

Understanding Business Interests in International Large-Scale Student Assessments: A Media Analysis of "The Economist," "Financial Times," and "Wall Street Journal"

Science.gov (United States)

Steiner-Khamsi, Gita; Appleton, Margaret; Vellani, Shezleen

2018-01-01

The media analysis is situated in the larger body of studies that explore the varied reasons why different policy actors advocate for international large-scale student assessments (ILSAs) and adds to the research on the fast advance of the global education industry. The analysis of "The Economist," "Financial Times," and…

Signatures of non-universal large scales in conditional structure functions from various turbulent flows

International Nuclear Information System (INIS)

Blum, Daniel B; Voth, Greg A; Bewley, Gregory P; Bodenschatz, Eberhard; Gibert, Mathieu; Xu Haitao; Gylfason, Ármann; Mydlarski, Laurent; Yeung, P K

2011-01-01

We present a systematic comparison of conditional structure functions in nine turbulent flows. The flows studied include forced isotropic turbulence simulated on a periodic domain, passive grid wind tunnel turbulence in air and in pressurized SF 6 , active grid wind tunnel turbulence (in both synchronous and random driving modes), the flow between counter-rotating discs, oscillating grid turbulence and the flow in the Lagrangian exploration module (in both constant and random driving modes). We compare longitudinal Eulerian second-order structure functions conditioned on the instantaneous large-scale velocity in each flow to assess the ways in which the large scales affect the small scales in a variety of turbulent flows. Structure functions are shown to have larger values when the large-scale velocity significantly deviates from the mean in most flows, suggesting that dependence on the large scales is typical in many turbulent flows. The effects of the large-scale velocity on the structure functions can be quite strong, with the structure function varying by up to a factor of 2 when the large-scale velocity deviates from the mean by ±2 standard deviations. In several flows, the effects of the large-scale velocity are similar at all the length scales we measured, indicating that the large-scale effects are scale independent. In a few flows, the effects of the large-scale velocity are larger on the smallest length scales. (paper)

Enabling High Performance Large Scale Dense Problems through KBLAS

KAUST Repository

Abdelfattah, Ahmad

2014-05-04

KBLAS (KAUST BLAS) is a small library that provides highly optimized BLAS routines on systems accelerated with GPUs. KBLAS is entirely written in CUDA C, and targets NVIDIA GPUs with compute capability 2.0 (Fermi) or higher. The current focus is on level-2 BLAS routines, namely the general matrix vector multiplication (GEMV) kernel, and the symmetric/hermitian matrix vector multiplication (SYMV/HEMV) kernel. KBLAS provides these two kernels in all four precisions (s, d, c, and z), with support to multi-GPU systems. Through advanced optimization techniques that target latency hiding and pushing memory bandwidth to the limit, KBLAS outperforms state-of-the-art kernels by 20-90% improvement. Competitors include CUBLAS-5.5, MAGMABLAS-1.4.0, and CULAR17. The SYMV/HEMV kernel from KBLAS has been adopted by NVIDIA, and should appear in CUBLAS-6.0. KBLAS has been used in large scale simulations of multi-object adaptive optics.

Large Scale GW Calculations on the Cori System

Science.gov (United States)

Deslippe, Jack; Del Ben, Mauro; da Jornada, Felipe; Canning, Andrew; Louie, Steven

The NERSC Cori system, powered by 9000+ Intel Xeon-Phi processors, represents one of the largest HPC systems for open-science in the United States and the world. We discuss the optimization of the GW methodology for this system, including both node level and system-scale optimizations. We highlight multiple large scale (thousands of atoms) case studies and discuss both absolute application performance and comparison to calculations on more traditional HPC architectures. We find that the GW method is particularly well suited for many-core architectures due to the ability to exploit a large amount of parallelism across many layers of the system. This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division, as part of the Computational Materials Sciences Program.

Low-Complexity Transmit Antenna Selection and Beamforming for Large-Scale MIMO Communications

Directory of Open Access Journals (Sweden)

Kun Qian

2014-01-01

Full Text Available Transmit antenna selection plays an important role in large-scale multiple-input multiple-output (MIMO communications, but optimal large-scale MIMO antenna selection is a technical challenge. Exhaustive search is often employed in antenna selection, but it cannot be efficiently implemented in large-scale MIMO communication systems due to its prohibitive high computation complexity. This paper proposes a low-complexity interactive multiple-parameter optimization method for joint transmit antenna selection and beamforming in large-scale MIMO communication systems. The objective is to jointly maximize the channel outrage capacity and signal-to-noise (SNR performance and minimize the mean square error in transmit antenna selection and minimum variance distortionless response (MVDR beamforming without exhaustive search. The effectiveness of all the proposed methods is verified by extensive simulation results. It is shown that the required antenna selection processing time of the proposed method does not increase along with the increase of selected antennas, but the computation complexity of conventional exhaustive search method will significantly increase when large-scale antennas are employed in the system. This is particularly useful in antenna selection for large-scale MIMO communication systems.

Towards Large-area Field-scale Operational Evapotranspiration for Water Use Mapping

Science.gov (United States)

Senay, G. B.; Friedrichs, M.; Morton, C.; Huntington, J. L.; Verdin, J.

2017-12-01

Field-scale evapotranspiration (ET) estimates are needed for improving surface and groundwater use and water budget studies. Ideally, field-scale ET estimates would be at regional to national levels and cover long time periods. As a result of large data storage and computational requirements associated with processing field-scale satellite imagery such as Landsat, numerous challenges remain to develop operational ET estimates over large areas for detailed water use and availability studies. However, the combination of new science, data availability, and cloud computing technology is enabling unprecedented capabilities for ET mapping. To demonstrate this capability, we used Google's Earth Engine cloud computing platform to create nationwide annual ET estimates with 30-meter resolution Landsat ( 16,000 images) and gridded weather data using the Operational Simplified Surface Energy Balance (SSEBop) model in support of the National Water Census, a USGS research program designed to build decision support capacity for water management agencies and other natural resource managers. By leveraging Google's Earth Engine Application Programming Interface (API) and developing software in a collaborative, open-platform environment, we rapidly advance from research towards applications for large-area field-scale ET mapping. Cloud computing of the Landsat image archive combined with other satellite, climate, and weather data, is creating never imagined opportunities for assessing ET model behavior and uncertainty, and ultimately providing the ability for more robust operational monitoring and assessment of water use at field-scales.

Networks and landscapes: a framework for setting goals and evaluating performance at the large landscape scale

Science.gov (United States)

R Patrick Bixler; Shawn Johnson; Kirk Emerson; Tina Nabatchi; Melly Reuling; Charles Curtin; Michele Romolini; Morgan Grove

2016-01-01

The objective of large landscape conser vation is to mitigate complex ecological problems through interventions at multiple and overlapping scales. Implementation requires coordination among a diverse network of individuals and organizations to integrate local-scale conservation activities with broad-scale goals. This requires an understanding of the governance options...

Feasibility Assessment of Using Power Plant Waste Heat in Large Scale Horticulture Facility Energy Supply Systems

Directory of Open Access Journals (Sweden)

Min Gyung Yu

2016-02-01

Full Text Available Recently, the Korean government has been carrying out projects to construct several large scale horticulture facilities. However, it is difficult for an energy supply to operate stably and economically with only a conventional fossil fuel boiler system. For this reason, several unused energy sources have become attractive and it was found that power plant waste heat has the greatest potential for application in this scenario. In this study, we performed a feasibility assessment of power plant waste heat as an energy source for horticulture facilities. As a result, it was confirmed that there was a sufficient amount of energy potential for the use of waste heat to supply energy to the assumed area. In Dangjin, an horticultural area of 500 ha could be constructed by utilizing 20% of the energy reserves. In Hadong, a horticulture facility can be set up to be 260 ha with 7.4% of the energy reserves. In Youngdong, an assumed area of 65 ha could be built utilizing about 19% of the energy reserves. Furthermore, the payback period was calculated in order to evaluate the economic feasibility compared with a conventional system. The initial investment costs can be recovered by the approximately 83% reduction in the annual operating costs.

Parallel clustering algorithm for large-scale biological data sets.

Science.gov (United States)

Wang, Minchao; Zhang, Wu; Ding, Wang; Dai, Dongbo; Zhang, Huiran; Xie, Hao; Chen, Luonan; Guo, Yike; Xie, Jiang

2014-01-01

Recent explosion of biological data brings a great challenge for the traditional clustering algorithms. With increasing scale of data sets, much larger memory and longer runtime are required for the cluster identification problems. The affinity propagation algorithm outperforms many other classical clustering algorithms and is widely applied into the biological researches. However, the time and space complexity become a great bottleneck when handling the large-scale data sets. Moreover, the similarity matrix, whose constructing procedure takes long runtime, is required before running the affinity propagation algorithm, since the algorithm clusters data sets based on the similarities between data pairs. Two types of parallel architectures are proposed in this paper to accelerate the similarity matrix constructing procedure and the affinity propagation algorithm. The memory-shared architecture is used to construct the similarity matrix, and the distributed system is taken for the affinity propagation algorithm, because of its large memory size and great computing capacity. An appropriate way of data partition and reduction is designed in our method, in order to minimize the global communication cost among processes. A speedup of 100 is gained with 128 cores. The runtime is reduced from serval hours to a few seconds, which indicates that parallel algorithm is capable of handling large-scale data sets effectively. The parallel affinity propagation also achieves a good performance when clustering large-scale gene data (microarray) and detecting families in large protein superfamilies.

The Rights and Responsibility of Test Takers When Large-Scale Testing Is Used for Classroom Assessment

Science.gov (United States)

van Barneveld, Christina; Brinson, Karieann

2017-01-01

The purpose of this research was to identify conflicts in the rights and responsibility of Grade 9 test takers when some parts of a large-scale test are marked by teachers and used in the calculation of students' class marks. Data from teachers' questionnaires and students' questionnaires from a 2009-10 administration of a large-scale test of…

Large-scale perspective as a challenge

NARCIS (Netherlands)

Plomp, M.G.A.

2012-01-01

1. Scale forms a challenge for chain researchers: when exactly is something ‘large-scale’? What are the underlying factors (e.g. number of parties, data, objects in the chain, complexity) that determine this? It appears to be a continuum between small- and large-scale, where positioning on that

Algorithm 896: LSA: Algorithms for Large-Scale Optimization

Czech Academy of Sciences Publication Activity Database

Lukšan, Ladislav; Matonoha, Ctirad; Vlček, Jan

2009-01-01

Roč. 36, č. 3 (2009), 16-1-16-29 ISSN 0098-3500 R&D Pro jects: GA AV ČR IAA1030405; GA ČR GP201/06/P397 Institutional research plan: CEZ:AV0Z10300504 Keywords : algorithms * design * large-scale optimization * large-scale nonsmooth optimization * large-scale nonlinear least squares * large-scale nonlinear minimax * large-scale systems of nonlinear equations * sparse pro blems * partially separable pro blems * limited-memory methods * discrete Newton methods * quasi-Newton methods * primal interior-point methods Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 1.904, year: 2009

Large-scale Intelligent Transporation Systems simulation

Energy Technology Data Exchange (ETDEWEB)

Ewing, T.; Canfield, T.; Hannebutte, U.; Levine, D.; Tentner, A.

1995-06-01

A prototype computer system has been developed which defines a high-level architecture for a large-scale, comprehensive, scalable simulation of an Intelligent Transportation System (ITS) capable of running on massively parallel computers and distributed (networked) computer systems. The prototype includes the modelling of instrumented ``smart`` vehicles with in-vehicle navigation units capable of optimal route planning and Traffic Management Centers (TMC). The TMC has probe vehicle tracking capabilities (display position and attributes of instrumented vehicles), and can provide 2-way interaction with traffic to provide advisories and link times. Both the in-vehicle navigation module and the TMC feature detailed graphical user interfaces to support human-factors studies. The prototype has been developed on a distributed system of networked UNIX computers but is designed to run on ANL`s IBM SP-X parallel computer system for large scale problems. A novel feature of our design is that vehicles will be represented by autonomus computer processes, each with a behavior model which performs independent route selection and reacts to external traffic events much like real vehicles. With this approach, one will be able to take advantage of emerging massively parallel processor (MPP) systems.

Large-scale renewable energy project barriers: Environmental impact assessment streamlining efforts in Japan and the EU

International Nuclear Information System (INIS)

Schumacher, Kim

2017-01-01

Environmental Impact Assessment (EIA) procedures have been identified as a major barrier to renewable energy (RE) development with regards to large-scale projects (LS-RE). However EIA laws have also been neglected by many decision-makers who have been underestimating its impact on RE development and the stifling potential they possess. As a consequence, apart from acknowledging the shortcomings of the systems currently in place, few governments momentarily have concrete plans to reform their EIA laws. By looking at recent EIA streamlining efforts in two industrialized regions that underwent major transformations in their energy sectors, this paper attempts to assess how such reform efforts can act as a means to support the balancing of environmental protection and climate change mitigation with socio-economic challenges. Thereby this paper fills this intellectual void by identifying the strengths and weaknesses of the Japanese EIA law by contrasting it with the recently revised EIA Directive of the European Union (EU). This enables the identification of the regulatory provisions that impact RE development the most and the determination of how structured EIA law reforms would affect domestic RE project development. The main focus lies on the evaluation of regulatory streamlining efforts in the Japanese and EU contexts through the application of a mixed-methods approach, consisting of in-depth literary and legal reviews, followed by a comparative analysis and a series of semi-structured interviews. Highlighting several legal inconsistencies in combination with the views of EIA professionals, academics and law- and policymakers, allowed for a more comprehensive assessment of what streamlining elements of the reformed EU EIA Directive and the proposed Japanese EIA framework modifications could either promote or stifle further RE deployment. - Highlights: •Performs an in-depth review of EIA reforms in OECD territories •First paper to compare Japan and the European

WImpiBLAST: web interface for mpiBLAST to help biologists perform large-scale annotation using high performance computing.

Directory of Open Access Journals (Sweden)

Parichit Sharma

Full Text Available The function of a newly sequenced gene can be discovered by determining its sequence homology with known proteins. BLAST is the most extensively used sequence analysis program for sequence similarity search in large databases of sequences. With the advent of next generation sequencing technologies it has now become possible to study genes and their expression at a genome-wide scale through RNA-seq and metagenome sequencing experiments. Functional annotation of all the genes is done by sequence similarity search against multiple protein databases. This annotation task is computationally very intensive and can take days to obtain complete results. The program mpiBLAST, an open-source parallelization of BLAST that achieves superlinear speedup, can be used to accelerate large-scale annotation by using supercomputers and high performance computing (HPC clusters. Although many parallel bioinformatics applications using the Message Passing Interface (MPI are available in the public domain, researchers are reluctant to use them due to lack of expertise in the Linux command line and relevant programming experience. With these limitations, it becomes difficult for biologists to use mpiBLAST for accelerating annotation. No web interface is available in the open-source domain for mpiBLAST. We have developed WImpiBLAST, a user-friendly open-source web interface for parallel BLAST searches. It is implemented in Struts 1.3 using a Java backbone and runs atop the open-source Apache Tomcat Server. WImpiBLAST supports script creation and job submission features and also provides a robust job management interface for system administrators. It combines script creation and modification features with job monitoring and management through the Torque resource manager on a Linux-based HPC cluster. Use case information highlights the acceleration of annotation analysis achieved by using WImpiBLAST. Here, we describe the WImpiBLAST web interface features and architecture

WImpiBLAST: web interface for mpiBLAST to help biologists perform large-scale annotation using high performance computing.

Science.gov (United States)

Sharma, Parichit; Mantri, Shrikant S

2014-01-01

The function of a newly sequenced gene can be discovered by determining its sequence homology with known proteins. BLAST is the most extensively used sequence analysis program for sequence similarity search in large databases of sequences. With the advent of next generation sequencing technologies it has now become possible to study genes and their expression at a genome-wide scale through RNA-seq and metagenome sequencing experiments. Functional annotation of all the genes is done by sequence similarity search against multiple protein databases. This annotation task is computationally very intensive and can take days to obtain complete results. The program mpiBLAST, an open-source parallelization of BLAST that achieves superlinear speedup, can be used to accelerate large-scale annotation by using supercomputers and high performance computing (HPC) clusters. Although many parallel bioinformatics applications using the Message Passing Interface (MPI) are available in the public domain, researchers are reluctant to use them due to lack of expertise in the Linux command line and relevant programming experience. With these limitations, it becomes difficult for biologists to use mpiBLAST for accelerating annotation. No web interface is available in the open-source domain for mpiBLAST. We have developed WImpiBLAST, a user-friendly open-source web interface for parallel BLAST searches. It is implemented in Struts 1.3 using a Java backbone and runs atop the open-source Apache Tomcat Server. WImpiBLAST supports script creation and job submission features and also provides a robust job management interface for system administrators. It combines script creation and modification features with job monitoring and management through the Torque resource manager on a Linux-based HPC cluster. Use case information highlights the acceleration of annotation analysis achieved by using WImpiBLAST. Here, we describe the WImpiBLAST web interface features and architecture, explain design

Preliminary melter performance assessment report

International Nuclear Information System (INIS)

Elliott, M.L.; Eyler, L.L.; Mahoney, L.A.; Cooper, M.F.; Whitney, L.D.; Shafer, P.J.

1994-08-01

The Melter Performance Assessment activity, a component of the Pacific Northwest Laboratory's (PNL) Vitrification Technology Development (PVTD) effort, was designed to determine the impact of noble metals on the operational life of the reference Hanford Waste Vitrification Plant (HWVP) melter. The melter performance assessment consisted of several activities, including a literature review of all work done with noble metals in glass, gradient furnace testing to study the behavior of noble metals during the melting process, research-scale and engineering-scale melter testing to evaluate effects of noble metals on melter operation, and computer modeling that used the experimental data to predict effects of noble metals on the full-scale melter. Feed used in these tests simulated neutralized current acid waste (NCAW) feed. This report summarizes the results of the melter performance assessment and predicts the lifetime of the HWVP melter. It should be noted that this work was conducted before the recent Tri-Party Agreement changes, so the reference melter referred to here is the Defense Waste Processing Facility (DWPF) melter design

Large Scale Evapotranspiration Estimates: An Important Component in Regional Water Balances to Assess Water Availability

Science.gov (United States)

Garatuza-Payan, J.; Yepez, E. A.; Watts, C.; Rodriguez, J. C.; Valdez-Torres, L. C.; Robles-Morua, A.

2013-05-01

Water security, can be defined as the reliable supply in quantity and quality of water to help sustain future populations and maintaining ecosystem health and productivity. Water security is rapidly declining in many parts of the world due to population growth, drought, climate change, salinity, pollution, land use change, over-allocation and over-utilization, among other issues. Governmental offices (such as the Comision Nacional del Agua in Mexico, CONAGUA) require and conduct studies to estimate reliable water balances at regional or continental scales in order to provide reasonable assessments of the amount of water that can be provided (from surface or ground water sources) to supply all the human needs while maintaining natural vegetation, on an operational basis and, more important, under disturbances, such as droughts. Large scale estimates of evapotranspiration (ET), a critical component of the water cycle, are needed for a better comprehension of the hydrological cycle at large scales, which, in most water balances is left as the residual. For operational purposes, such water balance estimates can not rely on ET measurements since they do not exist, should be simple and require the least ground information possible, information that is often scarce or does not exist at all. Given this limitation, the use of remotely sensed data to estimate ET could supplement the lack of ground information, particularly in remote regions In this study, a simple method, based on the Makkink equation is used to estimate ET for large areas at high spatial resolutions (1 km). The Makkink model used here is forced using three remotely sensed datasets. First, the model uses solar radiation estimates obtained from the Geostationary Operational Environmental Satellite (GOES); Second, the model uses an Enhanced Vegetation Index (EVI) obtained from the Moderate-resolution Imaging Spectroradiometer (MODIS) normalized to get an estimate for vegetation amount and land use which was

Modeling the Hydrologic Effects of Large-Scale Green Infrastructure Projects with GIS

Science.gov (United States)

Bado, R. A.; Fekete, B. M.; Khanbilvardi, R.

2015-12-01

Impervious surfaces in urban areas generate excess runoff, which in turn causes flooding, combined sewer overflows, and degradation of adjacent surface waters. Municipal environmental protection agencies have shown a growing interest in mitigating these effects with 'green' infrastructure practices that partially restore the perviousness and water holding capacity of urban centers. Assessment of the performance of current and future green infrastructure projects is hindered by the lack of adequate hydrological modeling tools; conventional techniques fail to account for the complex flow pathways of urban environments, and detailed analyses are difficult to prepare for the very large domains in which green infrastructure projects are implemented. Currently, no standard toolset exists that can rapidly and conveniently predict runoff, consequent inundations, and sewer overflows at a city-wide scale. We demonstrate how streamlined modeling techniques can be used with open-source GIS software to efficiently model runoff in large urban catchments. Hydraulic parameters and flow paths through city blocks, roadways, and sewer drains are automatically generated from GIS layers, and ultimately urban flow simulations can be executed for a variety of rainfall conditions. With this methodology, users can understand the implications of large-scale land use changes and green/gray storm water retention systems on hydraulic loading, peak flow rates, and runoff volumes.

Large-scale performance studies of the Resistive Plate Chamber fast tracker for the ATLAS 1st-level muon trigger

CERN Document Server

Cattani, G; The ATLAS collaboration

2009-01-01

In the ATLAS experiment, Resistive Plate Chambers provide the first-level muon trigger and bunch crossing identification over large area of the barrel region, as well as being used as a very fast 2D tracker. To achieve these goals a system of about ~4000 gas gaps operating in avalanche mode was built (resulting in a total readout surface of about 16000 m2 segmented into 350000 strips) and is now fully operational in the ATLAS pit, where its functionality has been widely tested up to now using cosmic rays. Such a large scale system allows to study the performance of RPCs (both from the point of view of gas gaps and readout electronics) with unprecedented sensitivity to rare effects, as well as providing the means to correlate (in a statistically significant way) characteristics at production sites with performance during operation. Calibrating such a system means fine tuning thousands of parameters (involving both front-end electronics and gap voltage), as well as constantly monitoring performance and environm...

Large-scale matrix-handling subroutines 'ATLAS'

International Nuclear Information System (INIS)

Tsunematsu, Toshihide; Takeda, Tatsuoki; Fujita, Keiichi; Matsuura, Toshihiko; Tahara, Nobuo

1978-03-01

Subroutine package ''ATLAS'' has been developed for handling large-scale matrices. The package is composed of four kinds of subroutines, i.e., basic arithmetic routines, routines for solving linear simultaneous equations and for solving general eigenvalue problems and utility routines. The subroutines are useful in large scale plasma-fluid simulations. (auth.)

Performance Assessment of Turbulence Models for the Prediction of the Reactor Internal Flow in the Scale-down APR+

International Nuclear Information System (INIS)

Lee, Gonghee; Bang, Youngseok; Woo, Swengwoong; Kim, Dohyeong; Kang, Minku

2013-01-01

The types of errors in CFD simulation can be divided into the two main categories: numerical errors and model errors. Turbulence model is one of the important sources for model errors. In this study, in order to assess the prediction performance of Reynolds-averaged Navier-Stokes (RANS)-based two equations turbulence models for the analysis of flow distribution inside a 1/5 scale-down APR+, the simulation was conducted with the commercial CFD software, ANSYS CFX V. 14. In this study, in order to assess the prediction performance of turbulence models for the analysis of flow distribution inside a 1/5 scale-down APR+, the simulation was conducted with the commercial CFD software, ANSYS CFX V. 14. Both standard k-ε model and SST model predicted the similar flow pattern inside reactor. Therefore it was concluded that the prediction performance of both turbulence models was nearly same. Complex thermal-hydraulic characteristics exist inside reactor because the reactor internals consist of fuel assembly, control rod assembly, and the internal structures. Either flow distribution test for the scale-down reactor model or computational fluid dynamics (CFD) simulation have been conducted to understand these complex thermal-hydraulic features inside reactor

Towards Building a High Performance Spatial Query System for Large Scale Medical Imaging Data.

Science.gov (United States)

Aji, Ablimit; Wang, Fusheng; Saltz, Joel H

2012-11-06

Support of high performance queries on large volumes of scientific spatial data is becoming increasingly important in many applications. This growth is driven by not only geospatial problems in numerous fields, but also emerging scientific applications that are increasingly data- and compute-intensive. For example, digital pathology imaging has become an emerging field during the past decade, where examination of high resolution images of human tissue specimens enables more effective diagnosis, prediction and treatment of diseases. Systematic analysis of large-scale pathology images generates tremendous amounts of spatially derived quantifications of micro-anatomic objects, such as nuclei, blood vessels, and tissue regions. Analytical pathology imaging provides high potential to support image based computer aided diagnosis. One major requirement for this is effective querying of such enormous amount of data with fast response, which is faced with two major challenges: the "big data" challenge and the high computation complexity. In this paper, we present our work towards building a high performance spatial query system for querying massive spatial data on MapReduce. Our framework takes an on demand index building approach for processing spatial queries and a partition-merge approach for building parallel spatial query pipelines, which fits nicely with the computing model of MapReduce. We demonstrate our framework on supporting multi-way spatial joins for algorithm evaluation and nearest neighbor queries for microanatomic objects. To reduce query response time, we propose cost based query optimization to mitigate the effect of data skew. Our experiments show that the framework can efficiently support complex analytical spatial queries on MapReduce.

Development of performance assessment instrument based contextual learning for measuring students laboratory skills

Science.gov (United States)

Susilaningsih, E.; Khotimah, K.; Nurhayati, S.

2018-04-01

The assessment of laboratory skill in general hasn’t specific guideline in assessment, while the individual assessment of students during a performance and skill in performing laboratory is still not been observed and measured properly. Alternative assessment that can be used to measure student laboratory skill is use performance assessment. The purpose of this study was to determine whether the performance assessment instrument that the result of research can be used to assess basic skills student laboratory. This research was conducted by the Research and Development. The result of the data analysis performance assessment instruments developed feasible to implement and validation result 62.5 with very good categories for observation sheets laboratory skills and all of the components with the very good category. The procedure is the preliminary stages of research and development stages. Preliminary stages are divided in two, namely the field studies and literature studies. The development stages are divided into several parts, namely 1) development of the type instrument, 2) validation by an expert, 3) a limited scale trial, 4) large-scale trials and 5) implementation of the product. The instrument included in the category of effective because 26 from 29 students have very high laboratory skill and high laboratory skill. The research of performance assessment instrument is standard and can be used to assess basic skill student laboratory.

Computing the universe: how large-scale simulations illuminate galaxies and dark energy

Science.gov (United States)

O'Shea, Brian

2015-04-01

High-performance and large-scale computing is absolutely to understanding astronomical objects such as stars, galaxies, and the cosmic web. This is because these are structures that operate on physical, temporal, and energy scales that cannot be reasonably approximated in the laboratory, and whose complexity and nonlinearity often defies analytic modeling. In this talk, I show how the growth of computing platforms over time has facilitated our understanding of astrophysical and cosmological phenomena, focusing primarily on galaxies and large-scale structure in the Universe.

Probes of large-scale structure in the Universe

International Nuclear Information System (INIS)

Suto, Yasushi; Gorski, K.; Juszkiewicz, R.; Silk, J.

1988-01-01

Recent progress in observational techniques has made it possible to confront quantitatively various models for the large-scale structure of the Universe with detailed observational data. We develop a general formalism to show that the gravitational instability theory for the origin of large-scale structure is now capable of critically confronting observational results on cosmic microwave background radiation angular anisotropies, large-scale bulk motions and large-scale clumpiness in the galaxy counts. (author)

Potential Impact of Large Scale Abstraction on the Quality of Shallow ...

African Journals Online (AJOL)

PRO

Significant increase in crop production would not, however, be ... sounding) using Geonics EM34-3 and Abem SAS300C Terrameter to determine the aquifer (fresh water lens) ..... Final report on environmental impact assessment of large scale.

Utilization of Large Scale Surface Models for Detailed Visibility Analyses

Science.gov (United States)

Caha, J.; Kačmařík, M.

2017-11-01

This article demonstrates utilization of large scale surface models with small spatial resolution and high accuracy, acquired from Unmanned Aerial Vehicle scanning, for visibility analyses. The importance of large scale data for visibility analyses on the local scale, where the detail of the surface model is the most defining factor, is described. The focus is not only the classic Boolean visibility, that is usually determined within GIS, but also on so called extended viewsheds that aims to provide more information about visibility. The case study with examples of visibility analyses was performed on river Opava, near the Ostrava city (Czech Republic). The multiple Boolean viewshed analysis and global horizon viewshed were calculated to determine most prominent features and visibility barriers of the surface. Besides that, the extended viewshed showing angle difference above the local horizon, which describes angular height of the target area above the barrier, is shown. The case study proved that large scale models are appropriate data source for visibility analyses on local level. The discussion summarizes possible future applications and further development directions of visibility analyses.

Very Large-Scale Neighborhoods with Performance Guarantees for Minimizing Makespan on Parallel Machines

NARCIS (Netherlands)

Brueggemann, T.; Hurink, Johann L.; Vredeveld, T.; Woeginger, Gerhard

2006-01-01

We study the problem of minimizing the makespan on m parallel machines. We introduce a very large-scale neighborhood of exponential size (in the number of machines) that is based on a matching in a complete graph. The idea is to partition the jobs assigned to the same machine into two sets. This

A Ranking Approach on Large-Scale Graph With Multidimensional Heterogeneous Information.

Science.gov (United States)

Wei, Wei; Gao, Bin; Liu, Tie-Yan; Wang, Taifeng; Li, Guohui; Li, Hang

2016-04-01

Graph-based ranking has been extensively studied and frequently applied in many applications, such as webpage ranking. It aims at mining potentially valuable information from the raw graph-structured data. Recently, with the proliferation of rich heterogeneous information (e.g., node/edge features and prior knowledge) available in many real-world graphs, how to effectively and efficiently leverage all information to improve the ranking performance becomes a new challenging problem. Previous methods only utilize part of such information and attempt to rank graph nodes according to link-based methods, of which the ranking performances are severely affected by several well-known issues, e.g., over-fitting or high computational complexity, especially when the scale of graph is very large. In this paper, we address the large-scale graph-based ranking problem and focus on how to effectively exploit rich heterogeneous information of the graph to improve the ranking performance. Specifically, we propose an innovative and effective semi-supervised PageRank (SSP) approach to parameterize the derived information within a unified semi-supervised learning framework (SSLF-GR), then simultaneously optimize the parameters and the ranking scores of graph nodes. Experiments on the real-world large-scale graphs demonstrate that our method significantly outperforms the algorithms that consider such graph information only partially.

Large-scale grid management; Storskala Nettforvaltning

Energy Technology Data Exchange (ETDEWEB)

Langdal, Bjoern Inge; Eggen, Arnt Ove

2003-07-01

The network companies in the Norwegian electricity industry now have to establish a large-scale network management, a concept essentially characterized by (1) broader focus (Broad Band, Multi Utility,...) and (2) bigger units with large networks and more customers. Research done by SINTEF Energy Research shows so far that the approaches within large-scale network management may be structured according to three main challenges: centralization, decentralization and out sourcing. The article is part of a planned series.

Large scale laboratory diffusion experiments in clay rocks

International Nuclear Information System (INIS)

Garcia-Gutierrez, M.; Missana, T.; Mingarro, M.; Martin, P.L.; Cormenzana, J.L.

2005-01-01

Full text of publication follows: Clay formations are potential host rocks for high-level radioactive waste repositories. In clay materials the radionuclide diffusion is the main transport mechanism. Thus, the understanding of the diffusion processes and the determination of diffusion parameters in conditions as similar as possible to the real ones, are critical for the performance assessment of deep geological repository. Diffusion coefficients are mainly measured in the laboratory using small samples, after a preparation to fit into the diffusion cell. In addition, a few field tests are usually performed for confirming laboratory results, and analyse scale effects. In field or 'in situ' tests the experimental set-up usually includes the injection of a tracer diluted in reconstituted formation water into a packed off section of a borehole. Both experimental systems may produce artefacts in the determination of diffusion coefficients. In laboratory the preparation of the sample can generate structural change mainly if the consolidated clay have a layered fabric, and in field test the introduction of water could modify the properties of the saturated clay in the first few centimeters, just where radionuclide diffusion is expected to take place. In this work, a large scale laboratory diffusion experiment is proposed, using a large cylindrical sample of consolidated clay that can overcome the above mentioned problems. The tracers used were mixed with clay obtained by drilling a central hole, re-compacted into the hole at approximately the same density as the consolidated block and finally sealed. Neither additional treatment of the sample nor external monitoring are needed. After the experimental time needed for diffusion to take place (estimated by scoping calculations) the block was sampled to obtain a 3D distribution of the tracer concentration and the results were modelled. An additional advantage of the proposed configuration is that it could be used in 'in situ

Japanese large-scale interferometers

CERN Document Server

Kuroda, K; Miyoki, S; Ishizuka, H; Taylor, C T; Yamamoto, K; Miyakawa, O; Fujimoto, M K; Kawamura, S; Takahashi, R; Yamazaki, T; Arai, K; Tatsumi, D; Ueda, A; Fukushima, M; Sato, S; Shintomi, T; Yamamoto, A; Suzuki, T; Saitô, Y; Haruyama, T; Sato, N; Higashi, Y; Uchiyama, T; Tomaru, T; Tsubono, K; Ando, M; Takamori, A; Numata, K; Ueda, K I; Yoneda, H; Nakagawa, K; Musha, M; Mio, N; Moriwaki, S; Somiya, K; Araya, A; Kanda, N; Telada, S; Sasaki, M; Tagoshi, H; Nakamura, T; Tanaka, T; Ohara, K

2002-01-01

The objective of the TAMA 300 interferometer was to develop advanced technologies for kilometre scale interferometers and to observe gravitational wave events in nearby galaxies. It was designed as a power-recycled Fabry-Perot-Michelson interferometer and was intended as a step towards a final interferometer in Japan. The present successful status of TAMA is presented. TAMA forms a basis for LCGT (large-scale cryogenic gravitational wave telescope), a 3 km scale cryogenic interferometer to be built in the Kamioka mine in Japan, implementing cryogenic mirror techniques. The plan of LCGT is schematically described along with its associated R and D.

Novel material and structural design for large-scale marine protective devices

International Nuclear Information System (INIS)

Qiu, Ang; Lin, Wei; Ma, Yong; Zhao, Chengbi; Tang, Youhong

2015-01-01

Highlights: • Large-scale protective devices with different structural designs have been optimized. • Large-scale protective devices with novel material designs have been optimized. • Protective devices constructed of sandwich panels have the best anti-collision performance. • Protective devices with novel material design can reduce weight and construction cost. - Abstract: Large-scale protective devices must endure the impact of severe forces, large structural deformation, the increased stress and strain rate effects, and multiple coupling effects. In evaluation of the safety of conceptual design through simulation, several key parameters considered in this research are maximum impact force, energy dissipated by the impactor (e.g. a ship) and energy absorbed by the device and the impactor stroke. During impact, the main function of the ring beam structure is to resist and buffer the impact force between ship and bridge pile caps, which could guarantee that the magnitude of impact force meets the corresponding requirements. The means of improving anti-collision performance can be to increase the strength of the beam section or to exchange the steel material with novel fiber reinforced polymer laminates. The main function of the buoyancy tank is to absorb and transfer the ship’s kinetic energy through large plastic deformation, damage, or friction occurring within itself. The energy absorption effect can be improved by structure optimization or by the use of new sandwich panels. Structural and material optimization schemes are proposed on the basis of conceptual design in this research, and protective devices constructed of sandwich panels prove to have the best anti-collision performance

Quantitative Missense Variant Effect Prediction Using Large-Scale Mutagenesis Data.

Science.gov (United States)

Gray, Vanessa E; Hause, Ronald J; Luebeck, Jens; Shendure, Jay; Fowler, Douglas M

2018-01-24

Large datasets describing the quantitative effects of mutations on protein function are becoming increasingly available. Here, we leverage these datasets to develop Envision, which predicts the magnitude of a missense variant's molecular effect. Envision combines 21,026 variant effect measurements from nine large-scale experimental mutagenesis datasets, a hitherto untapped training resource, with a supervised, stochastic gradient boosting learning algorithm. Envision outperforms other missense variant effect predictors both on large-scale mutagenesis data and on an independent test dataset comprising 2,312 TP53 variants whose effects were measured using a low-throughput approach. This dataset was never used for hyperparameter tuning or model training and thus serves as an independent validation set. Envision prediction accuracy is also more consistent across amino acids than other predictors. Finally, we demonstrate that Envision's performance improves as more large-scale mutagenesis data are incorporated. We precompute Envision predictions for every possible single amino acid variant in human, mouse, frog, zebrafish, fruit fly, worm, and yeast proteomes (https://envision.gs.washington.edu/). Copyright © 2017 Elsevier Inc. All rights reserved.

A concurrent visualization system for large-scale unsteady simulations. Parallel vector performance on an NEC SX-4

International Nuclear Information System (INIS)

Takei, Toshifumi; Doi, Shun; Matsumoto, Hideki; Muramatsu, Kazuhiro

2000-01-01

We have developed a concurrent visualization system RVSLIB (Real-time Visual Simulation Library). This paper shows the effectiveness of the system when it is applied to large-scale unsteady simulations, for which the conventional post-processing approach may no longer work, on high-performance parallel vector supercomputers. The system performs almost all of the visualization tasks on a computation server and uses compressed visualized image data for efficient communication between the server and the user terminal. We have introduced several techniques, including vectorization and parallelization, into the system to minimize the computational costs of the visualization tools. The performance of RVSLIB was evaluated by using an actual CFD code on an NEC SX-4. The computational time increase due to the concurrent visualization was at most 3% for a smaller (1.6 million) grid and less than 1% for a larger (6.2 million) one. (author)

A Decentralized Multivariable Robust Adaptive Voltage and Speed Regulator for Large-Scale Power Systems

Science.gov (United States)

Okou, Francis A.; Akhrif, Ouassima; Dessaint, Louis A.; Bouchard, Derrick

2013-05-01

This papter introduces a decentralized multivariable robust adaptive voltage and frequency regulator to ensure the stability of large-scale interconnnected generators. Interconnection parameters (i.e. load, line and transormer parameters) are assumed to be unknown. The proposed design approach requires the reformulation of conventiaonal power system models into a multivariable model with generator terminal voltages as state variables, and excitation and turbine valve inputs as control signals. This model, while suitable for the application of modern control methods, introduces problems with regards to current design techniques for large-scale systems. Interconnection terms, which are treated as perturbations, do not meet the common matching condition assumption. A new adaptive method for a certain class of large-scale systems is therefore introduces that does not require the matching condition. The proposed controller consists of nonlinear inputs that cancel some nonlinearities of the model. Auxiliary controls with linear and nonlinear components are used to stabilize the system. They compensate unknown parametes of the model by updating both the nonlinear component gains and excitation parameters. The adaptation algorithms involve the sigma-modification approach for auxiliary control gains, and the projection approach for excitation parameters to prevent estimation drift. The computation of the matrix-gain of the controller linear component requires the resolution of an algebraic Riccati equation and helps to solve the perturbation-mismatching problem. A realistic power system is used to assess the proposed controller performance. The results show that both stability and transient performance are considerably improved following a severe contingency.

Design study on sodium-cooled large-scale reactor

International Nuclear Information System (INIS)

Shimakawa, Yoshio; Nibe, Nobuaki; Hori, Toru

2002-05-01

In Phase 1 of the 'Feasibility Study on Commercialized Fast Reactor Cycle Systems (F/S)', an advanced loop type reactor has been selected as a promising concept of sodium-cooled large-scale reactor, which has a possibility to fulfill the design requirements of the F/S. In Phase 2 of the F/S, it is planed to precede a preliminary conceptual design of a sodium-cooled large-scale reactor based on the design of the advanced loop type reactor. Through the design study, it is intended to construct such a plant concept that can show its attraction and competitiveness as a commercialized reactor. This report summarizes the results of the design study on the sodium-cooled large-scale reactor performed in JFY2001, which is the first year of Phase 2. In the JFY2001 design study, a plant concept has been constructed based on the design of the advanced loop type reactor, and fundamental specifications of main systems and components have been set. Furthermore, critical subjects related to safety, structural integrity, thermal hydraulics, operability, maintainability and economy have been examined and evaluated. As a result of this study, the plant concept of the sodium-cooled large-scale reactor has been constructed, which has a prospect to satisfy the economic goal (construction cost: less than 200,000yens/kWe, etc.) and has a prospect to solve the critical subjects. From now on, reflecting the results of elemental experiments, the preliminary conceptual design of this plant will be preceded toward the selection for narrowing down candidate concepts at the end of Phase 2. (author)

Low-Temperature Soft-Cover Deposition of Uniform Large-Scale Perovskite Films for High-Performance Solar Cells.

Science.gov (United States)

Ye, Fei; Tang, Wentao; Xie, Fengxian; Yin, Maoshu; He, Jinjin; Wang, Yanbo; Chen, Han; Qiang, Yinghuai; Yang, Xudong; Han, Liyuan

2017-09-01

Large-scale high-quality perovskite thin films are crucial to produce high-performance perovskite solar cells. However, for perovskite films fabricated by solvent-rich processes, film uniformity can be prevented by convection during thermal evaporation of the solvent. Here, a scalable low-temperature soft-cover deposition (LT-SCD) method is presented, where the thermal convection-induced defects in perovskite films are eliminated through a strategy of surface tension relaxation. Compact, homogeneous, and convection-induced-defects-free perovskite films are obtained on an area of 12 cm 2 , which enables a power conversion efficiency (PCE) of 15.5% on a solar cell with an area of 5 cm 2 . This is the highest efficiency at this large cell area. A PCE of 15.3% is also obtained on a flexible perovskite solar cell deposited on the polyethylene terephthalate substrate owing to the advantage of presented low-temperature processing. Hence, the present LT-SCD technology provides a new non-spin-coating route to the deposition of large-area uniform perovskite films for both rigid and flexible perovskite devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Modeling the impact of large-scale energy conversion systems on global climate

International Nuclear Information System (INIS)

Williams, J.

There are three energy options which could satisfy a projected energy requirement of about 30 TW and these are the solar, nuclear and (to a lesser extent) coal options. Climate models can be used to assess the impact of large scale deployment of these options. The impact of waste heat has been assessed using energy balance models and general circulation models (GCMs). Results suggest that the impacts are significant when the heat imput is very high and studies of more realistic scenarios are required. Energy balance models, radiative-convective models and a GCM have been used to study the impact of doubling the atmospheric CO 2 concentration. State-of-the-art models estimate a surface temperature increase of 1.5-3.0 0 C with large amplification near the poles, but much uncertainty remains. Very few model studies have been made of the impact of particles on global climate, more information on the characteristics of particle input are required. The impact of large-scale deployment of solar energy conversion systems has received little attention but model studies suggest that large scale changes in surface characteristics associated with such systems (surface heat balance, roughness and hydrological characteristics and ocean surface temperature) could have significant global climatic effects. (Auth.)

A visual analytics system for optimizing the performance of large-scale networks in supercomputing systems

Directory of Open Access Journals (Sweden)

Takanori Fujiwara

2018-03-01

Full Text Available The overall efficiency of an extreme-scale supercomputer largely relies on the performance of its network interconnects. Several of the state of the art supercomputers use networks based on the increasingly popular Dragonfly topology. It is crucial to study the behavior and performance of different parallel applications running on Dragonfly networks in order to make optimal system configurations and design choices, such as job scheduling and routing strategies. However, in order to study these temporal network behavior, we would need a tool to analyze and correlate numerous sets of multivariate time-series data collected from the Dragonfly’s multi-level hierarchies. This paper presents such a tool–a visual analytics system–that uses the Dragonfly network to investigate the temporal behavior and optimize the communication performance of a supercomputer. We coupled interactive visualization with time-series analysis methods to help reveal hidden patterns in the network behavior with respect to different parallel applications and system configurations. Our system also provides multiple coordinated views for connecting behaviors observed at different levels of the network hierarchies, which effectively helps visual analysis tasks. We demonstrate the effectiveness of the system with a set of case studies. Our system and findings can not only help improve the communication performance of supercomputing applications, but also the network performance of next-generation supercomputers. Keywords: Supercomputing, Parallel communication network, Dragonfly networks, Time-series data, Performance analysis, Visual analytics

Sensitivity of the scale partition for variational multiscale large-eddy simulation of channel flow

NARCIS (Netherlands)

Holmen, J.; Hughes, T.J.R.; Oberai, A.A.; Wells, G.N.

2004-01-01

The variational multiscale method has been shown to perform well for large-eddy simulation (LES) of turbulent flows. The method relies upon a partition of the resolved velocity field into large- and small-scale components. The subgrid model then acts only on the small scales of motion, unlike

Why small-scale cannabis growers stay small: five mechanisms that prevent small-scale growers from going large scale.

Science.gov (United States)

Hammersvik, Eirik; Sandberg, Sveinung; Pedersen, Willy

2012-11-01

Over the past 15-20 years, domestic cultivation of cannabis has been established in a number of European countries. New techniques have made such cultivation easier; however, the bulk of growers remain small-scale. In this study, we explore the factors that prevent small-scale growers from increasing their production. The study is based on 1 year of ethnographic fieldwork and qualitative interviews conducted with 45 Norwegian cannabis growers, 10 of whom were growing on a large-scale and 35 on a small-scale. The study identifies five mechanisms that prevent small-scale indoor growers from going large-scale. First, large-scale operations involve a number of people, large sums of money, a high work-load and a high risk of detection, and thus demand a higher level of organizational skills than for small growing operations. Second, financial assets are needed to start a large 'grow-site'. Housing rent, electricity, equipment and nutrients are expensive. Third, to be able to sell large quantities of cannabis, growers need access to an illegal distribution network and knowledge of how to act according to black market norms and structures. Fourth, large-scale operations require advanced horticultural skills to maximize yield and quality, which demands greater skills and knowledge than does small-scale cultivation. Fifth, small-scale growers are often embedded in the 'cannabis culture', which emphasizes anti-commercialism, anti-violence and ecological and community values. Hence, starting up large-scale production will imply having to renegotiate or abandon these values. Going from small- to large-scale cannabis production is a demanding task-ideologically, technically, economically and personally. The many obstacles that small-scale growers face and the lack of interest and motivation for going large-scale suggest that the risk of a 'slippery slope' from small-scale to large-scale growing is limited. Possible political implications of the findings are discussed. Copyright

Large scale gas injection test (Lasgit) performed at the Aespoe Hard Rock Laboratory. Summary report 2008

International Nuclear Information System (INIS)

Cuss, R.J.; Harrington, J.F.; Noy, D.J.

2010-02-01

This report describes the set-up, operation and observations from the first 1,385 days (3.8 years) of the large scale gas injection test (Lasgit) experiment conducted at the Aespoe Hard Rock Laboratory. During this time the bentonite buffer has been artificially hydrated and has given new insight into the evolution of the buffer. After 2 years (849 days) of artificial hydration a canister filter was identified to perform a series of hydraulic and gas tests, a period that lasted 268 days. The results from the gas test showed that the full-scale bentonite buffer behaved in a similar way to previous laboratory experiments. This confirms the up-scaling of laboratory observations with the addition of considerable information on the stress responses throughout the deposition hole. During the gas testing stage, the buffer was continued to artificially hydrate. Hydraulic results, from controlled and uncontrolled events, show that the buffer continues to mature and has yet to reach full maturation. Lasgit has yielded high quality data relating to the hydration of the bentonite and the evolution in hydrogeological properties adjacent to the deposition hole. The initial hydraulic and gas injection tests confirm the correct working of all control and data acquisition systems. Lasgit has been in successful operation for in excess of 1,385 days

Large scale gas injection test (Lasgit) performed at the Aespoe Hard Rock Laboratory. Summary report 2008

Energy Technology Data Exchange (ETDEWEB)

Cuss, R.J.; Harrington, J.F.; Noy, D.J. (British Geological Survey (United Kingdom))

2010-02-15

This report describes the set-up, operation and observations from the first 1,385 days (3.8 years) of the large scale gas injection test (Lasgit) experiment conducted at the Aespoe Hard Rock Laboratory. During this time the bentonite buffer has been artificially hydrated and has given new insight into the evolution of the buffer. After 2 years (849 days) of artificial hydration a canister filter was identified to perform a series of hydraulic and gas tests, a period that lasted 268 days. The results from the gas test showed that the full-scale bentonite buffer behaved in a similar way to previous laboratory experiments. This confirms the up-scaling of laboratory observations with the addition of considerable information on the stress responses throughout the deposition hole. During the gas testing stage, the buffer was continued to artificially hydrate. Hydraulic results, from controlled and uncontrolled events, show that the buffer continues to mature and has yet to reach full maturation. Lasgit has yielded high quality data relating to the hydration of the bentonite and the evolution in hydrogeological properties adjacent to the deposition hole. The initial hydraulic and gas injection tests confirm the correct working of all control and data acquisition systems. Lasgit has been in successful operation for in excess of 1,385 days

Distributed large-scale dimensional metrology new insights

CERN Document Server

Franceschini, Fiorenzo; Maisano, Domenico

2011-01-01

Focuses on the latest insights into and challenges of distributed large scale dimensional metrology Enables practitioners to study distributed large scale dimensional metrology independently Includes specific examples of the development of new system prototypes

Deterministic sensitivity and uncertainty analysis for large-scale computer models

International Nuclear Information System (INIS)

Worley, B.A.; Pin, F.G.; Oblow, E.M.; Maerker, R.E.; Horwedel, J.E.; Wright, R.Q.

1988-01-01

The fields of sensitivity and uncertainty analysis have traditionally been dominated by statistical techniques when large-scale modeling codes are being analyzed. These methods are able to estimate sensitivities, generate response surfaces, and estimate response probability distributions given the input parameter probability distributions. Because the statistical methods are computationally costly, they are usually applied only to problems with relatively small parameter sets. Deterministic methods, on the other hand, are very efficient and can handle large data sets, but generally require simpler models because of the considerable programming effort required for their implementation. The first part of this paper reports on the development and availability of two systems, GRESS and ADGEN, that make use of computer calculus compilers to automate the implementation of deterministic sensitivity analysis capability into existing computer models. This automation removes the traditional limitation of deterministic sensitivity methods. This second part of the paper describes a deterministic uncertainty analysis method (DUA) that uses derivative information as a basis to propagate parameter probability distributions to obtain result probability distributions. This paper is applicable to low-level radioactive waste disposal system performance assessment

Air pollutant dispersion from a large semi-enclosed stadium in an urban area: high-resolution CFD modeling versus full-scale measurements

NARCIS (Netherlands)

Hooff, van T.A.J.; Blocken, B.J.E.; Seppelt, R.; Voinov, A.A.; Lange, S.; Bankamp, D.

2012-01-01

Abstract: High-resolution CFD simulations and full-scale measurements have been performed to assess the dispersion of air pollutants (CO2) from the large semi-enclosed Amsterdam ArenA football stadium. The dispersion process is driven by natural ventilation by the urban wind flow and by buoyancy,

PERSEUS-HUB: Interactive and Collective Exploration of Large-Scale Graphs

Directory of Open Access Journals (Sweden)

Di Jin

2017-07-01

Full Text Available Graphs emerge naturally in many domains, such as social science, neuroscience, transportation engineering, and more. In many cases, such graphs have millions or billions of nodes and edges, and their sizes increase daily at a fast pace. How can researchers from various domains explore large graphs interactively and efficiently to find out what is ‘important’? How can multiple researchers explore a new graph dataset collectively and “help” each other with their findings? In this article, we present Perseus-Hub, a large-scale graph mining tool that computes a set of graph properties in a distributed manner, performs ensemble, multi-view anomaly detection to highlight regions that are worth investigating, and provides users with uncluttered visualization and easy interaction with complex graph statistics. Perseus-Hub uses a Spark cluster to calculate various statistics of large-scale graphs efficiently, and aggregates the results in a summary on the master node to support interactive user exploration. In Perseus-Hub, the visualized distributions of graph statistics provide preliminary analysis to understand a graph. To perform a deeper analysis, users with little prior knowledge can leverage patterns (e.g., spikes in the power-law degree distribution marked by other users or experts. Moreover, Perseus-Hub guides users to regions of interest by highlighting anomalous nodes and helps users establish a more comprehensive understanding about the graph at hand. We demonstrate our system through the case study on real, large-scale networks.

REQUIREMENTS FOR SYSTEMS DEVELOPMENT LIFE CYCLE MODELS FOR LARGE-SCALE DEFENSE SYSTEMS

Directory of Open Access Journals (Sweden)

Kadir Alpaslan DEMIR

2015-10-01

Full Text Available TLarge-scale defense system projects are strategic for maintaining and increasing the national defense capability. Therefore, governments spend billions of dollars in the acquisition and development of large-scale defense systems. The scale of defense systems is always increasing and the costs to build them are skyrocketing. Today, defense systems are software intensive and they are either a system of systems or a part of it. Historically, the project performances observed in the development of these systems have been signifi cantly poor when compared to other types of projects. It is obvious that the currently used systems development life cycle models are insuffi cient to address today’s challenges of building these systems. Using a systems development life cycle model that is specifi cally designed for largescale defense system developments and is effective in dealing with today’s and near-future challenges will help to improve project performances. The fi rst step in the development a large-scale defense systems development life cycle model is the identifi cation of requirements for such a model. This paper contributes to the body of literature in the fi eld by providing a set of requirements for system development life cycle models for large-scale defense systems. Furthermore, a research agenda is proposed.

Modeling Student Motivation and Students’ Ability Estimates From a Large-Scale Assessment of Mathematics

Directory of Open Access Journals (Sweden)

Carlos Zerpa

2011-09-01

Full Text Available When large-scale assessments (LSA do not hold personal stakes for students, students may not put forth their best effort. Low-effort examinee behaviors (e.g., guessing, omitting items result in an underestimate of examinee abilities, which is a concern when using results of LSA to inform educational policy and planning. The purpose of this study was to explore the relationship between examinee motivation as defined by expectancy-value theory, student effort, and examinee mathematics abilities. A principal components analysis was used to examine the data from Grade 9 students (n = 43,562 who responded to a self-report questionnaire on their attitudes and practices related to mathematics. The results suggested a two-component model where the components were interpreted as task-values in mathematics and student effort. Next, a hierarchical linear model was implemented to examine the relationship between examinee component scores and their estimated ability on a LSA. The results of this study provide evidence that motivation, as defined by the expectancy-value theory and student effort, partially explains student ability estimates and may have implications in the information that get transferred to testing organizations, school boards, and teachers while assessing students’ Grade 9 mathematics learning.

GPU-Accelerated Sparse Matrix Solvers for Large-Scale Simulations, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Many large-scale numerical simulations can be broken down into common mathematical routines. While the applications may differ, the need to perform functions such as...

SCALE INTERACTION IN A MIXING LAYER. THE ROLE OF THE LARGE-SCALE GRADIENTS

KAUST Repository

Fiscaletti, Daniele; Attili, Antonio; Bisetti, Fabrizio; Elsinga, Gerrit E.

2015-01-01

from physical considerations we would expect the scales to interact in a qualitatively similar way within the flow and across different turbulent flows. Therefore, instead of the large-scale fluctuations, the large-scale gradients modulation of the small scales has been additionally investigated.

Assessing large-scale weekly cycles in meteorological variables: a review

Directory of Open Access Journals (Sweden)

A. Sanchez-Lorenzo

2012-07-01

Full Text Available Several studies have claimed to have found significant weekly cycles of meteorological variables appearing over large domains, which can hardly be related to urban effects exclusively. Nevertheless, there is still an ongoing scientific debate whether these large-scale weekly cycles exist or not, and some other studies fail to reproduce them with statistical significance. In addition to the lack of the positive proof for the existence of these cycles, their possible physical explanations have been controversially discussed during the last years. In this work we review the main results about this topic published during the recent two decades, including a summary of the existence or non-existence of significant weekly weather cycles across different regions of the world, mainly over the US, Europe and Asia. In addition, some shortcomings of common statistical methods for analyzing weekly cycles are listed. Finally, a brief summary of supposed causes of the weekly cycles, focusing on the aerosol-cloud-radiation interactions and their impact on meteorological variables as a result of the weekly cycles of anthropogenic activities, and possible directions for future research, is presented.

Large-scale, multi-compartment tests in PANDA for LWR-containment analysis and code validation

International Nuclear Information System (INIS)

Paladino, Domenico; Auban, Olivier; Zboray, Robert

2006-01-01

The large-scale thermal-hydraulic PANDA facility has been used for the last years for investigating passive decay heat removal systems and related containment phenomena relevant for next-generation and current light water reactors. As part of the 5. EURATOM framework program project TEMPEST, a series of tests was performed in PANDA to experimentally investigate the distribution of hydrogen inside the containment and its effect on the performance of the Passive Containment Cooling System (PCCS) designed for the Economic Simplified Boiling Water Reactor (ESBWR). In a postulated severe accident, a large amount of hydrogen could be released in the Reactor Pressure Vessel (RPV) as a consequence of the cladding Metal- Water (M-W) reaction and discharged together with steam to the Drywell (DW) compartment. In PANDA tests, hydrogen was simulated by using helium. This paper illustrates the results of a TEMPEST test performed in PANDA and named as Test T1.2. In Test T1.2, the gas stratification (steam-helium) patterns forming in the large-scale multi-compartment PANDA DW, and the effect of non-condensable gas (helium) on the overall behaviour of the PCCS were identified. Gas mixing and stratification in a large-scale multi-compartment system are currently being further investigated in PANDA in the frame of the OECD project SETH. The testing philosophy in this new PANDA program is to produce data for code validation in relation to specific phenomena, such as: gas stratification in the containment, gas transport between containment compartments, wall condensation, etc. These types of phenomena are driven by buoyant high-momentum injections (jets) and/or low momentum injection (plumes), depending on the transient scenario. In this context, the new SETH tests in PANDA are particularly valuable to produce an experimental database for code assessment. This paper also presents an overview of the PANDA SETH tests and the major improvements in instrumentation carried out in the PANDA

Trends in large-scale testing of reactor structures

International Nuclear Information System (INIS)

Blejwas, T.E.

2003-01-01

Large-scale tests of reactor structures have been conducted at Sandia National Laboratories since the late 1970s. This paper describes a number of different large-scale impact tests, pressurization tests of models of containment structures, and thermal-pressure tests of models of reactor pressure vessels. The advantages of large-scale testing are evident, but cost, in particular limits its use. As computer models have grown in size, such as number of degrees of freedom, the advent of computer graphics has made possible very realistic representation of results - results that may not accurately represent reality. A necessary condition to avoiding this pitfall is the validation of the analytical methods and underlying physical representations. Ironically, the immensely larger computer models sometimes increase the need for large-scale testing, because the modeling is applied to increasing more complex structural systems and/or more complex physical phenomena. Unfortunately, the cost of large-scale tests is a disadvantage that will likely severely limit similar testing in the future. International collaborations may provide the best mechanism for funding future programs with large-scale tests. (author)

Performing a Large-Scale Modal Test on the B2 Stand Crane at NASA's Stennis Space Center

Science.gov (United States)

Stasiunas, Eric C.; Parks, Russel A.; Sontag, Brendan D.

2018-01-01

A modal test of NASA's Space Launch System (SLS) Core Stage is scheduled to occur at the Stennis Space Center B2 test stand. A derrick crane with a 150-ft long boom, located at the top of the stand, will be used to suspend the Core Stage in order to achieve defined boundary conditions. During this suspended modal test, it is expected that dynamic coupling will occur between the crane and the Core Stage. Therefore, a separate modal test was performed on the B2 crane itself, in order to evaluate the varying dynamic characteristics and correlate math models of the crane. Performing a modal test on such a massive structure was challenging and required creative test setup and procedures, including implementing both AC and DC accelerometers, and performing both classical hammer and operational modal analysis. This paper describes the logistics required to perform this large-scale test, as well as details of the test setup, the modal test methods used, and an overview and application of the results.

DECOVALEX III/BENCHPAR PROJECTS. Approaches to Upscaling Thermal-Hydro-Mechanical Processes in a Fractured Rock. Mass and its Significance for Large-Scale Repository Performance Assessment. Summary of Findings. Report of BMT2/WP3

International Nuclear Information System (INIS)

Andersson, Johan; Staub, Isabelle; Knight, Les

2005-02-01

The Benchmark Test 2 of DECOVALEX III and Work Package 3 of BENCHPAR concerns the upscaling Thermal (T), Hydrological (H) and Mechanical (M) processes in a fractured rock mass and its significance for large-scale repository performance assessment. The work is primarily concerned with the extent to which various thermo-hydro-mechanical couplings in a fractured rock mass adjacent to a repository are significant in terms of solute transport typically calculated in large-scale repository performance assessments. Since the presence of even quite small fractures may control the hydraulic, mechanical and coupled hydromechanical behaviour of the rock mass, a key of the work has been to explore the extent to which these can be upscaled and represented by 'equivalent' continuum properties appropriate PA calculations. From these general aims the BMT was set-up as a numerical study of a large scale reference problem. Analysing this reference problem should: help explore how different means of simplifying the geometrical detail of a site, with its implications on model parameters, ('upscaling') impacts model predictions of relevance to repository performance, explore to what extent the THM-coupling needs to be considered in relation to PA-measures, compare the uncertainties in upscaling (both to uncertainty on how to upscale or uncertainty that arises due to the upscaling processes) and consideration of THM couplings with the inherent uncertainty and spatial variability of the site specific data. Furthermore, it has been an essential component of the work that individual teams not only produce numerical results but are forced to make their own judgements and to provide the proper justification for their conclusions based on their analysis. It should also be understood that conclusions drawn will partly be specific to the problem analysed, in particular as it mainly concerns a 2D application. This means that specific conclusions may have limited applicability to real problems in

Large Scale Computations in Air Pollution Modelling

DEFF Research Database (Denmark)

Zlatev, Z.; Brandt, J.; Builtjes, P. J. H.

Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998......Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998...

Large-scale building energy efficiency retrofit: Concept, model and control

International Nuclear Information System (INIS)

Wu, Zhou; Wang, Bo; Xia, Xiaohua

2016-01-01

BEER (Building energy efficiency retrofit) projects are initiated in many nations and regions over the world. Existing studies of BEER focus on modeling and planning based on one building and one year period of retrofitting, which cannot be applied to certain large BEER projects with multiple buildings and multi-year retrofit. In this paper, the large-scale BEER problem is defined in a general TBT (time-building-technology) framework, which fits essential requirements of real-world projects. The large-scale BEER is newly studied in the control approach rather than the optimization approach commonly used before. Optimal control is proposed to design optimal retrofitting strategy in terms of maximal energy savings and maximal NPV (net present value). The designed strategy is dynamically changing on dimensions of time, building and technology. The TBT framework and the optimal control approach are verified in a large BEER project, and results indicate that promising performance of energy and cost savings can be achieved in the general TBT framework. - Highlights: • Energy efficiency retrofit of many buildings is studied. • A TBT (time-building-technology) framework is proposed. • The control system of the large-scale BEER is modeled. • The optimal retrofitting strategy is obtained.

Scale-Up: Improving Large Enrollment Physics Courses

Science.gov (United States)

Beichner, Robert

1999-11-01

The Student-Centered Activities for Large Enrollment University Physics (SCALE-UP) project is working to establish a learning environment that will promote increased conceptual understanding, improved problem-solving performance, and greater student satisfaction, while still maintaining class sizes of approximately 100. We are also addressing the new ABET engineering accreditation requirements for inquiry-based learning along with communication and team-oriented skills development. Results of studies of our latest classroom design, plans for future classroom space, and the current iteration of instructional materials will be discussed.

Environment and host as large-scale controls of ectomycorrhizal fungi.

Science.gov (United States)

van der Linde, Sietse; Suz, Laura M; Orme, C David L; Cox, Filipa; Andreae, Henning; Asi, Endla; Atkinson, Bonnie; Benham, Sue; Carroll, Christopher; Cools, Nathalie; De Vos, Bruno; Dietrich, Hans-Peter; Eichhorn, Johannes; Gehrmann, Joachim; Grebenc, Tine; Gweon, Hyun S; Hansen, Karin; Jacob, Frank; Kristöfel, Ferdinand; Lech, Paweł; Manninger, Miklós; Martin, Jan; Meesenburg, Henning; Merilä, Päivi; Nicolas, Manuel; Pavlenda, Pavel; Rautio, Pasi; Schaub, Marcus; Schröck, Hans-Werner; Seidling, Walter; Šrámek, Vít; Thimonier, Anne; Thomsen, Iben Margrete; Titeux, Hugues; Vanguelova, Elena; Verstraeten, Arne; Vesterdal, Lars; Waldner, Peter; Wijk, Sture; Zhang, Yuxin; Žlindra, Daniel; Bidartondo, Martin I

2018-06-06

Explaining the large-scale diversity of soil organisms that drive biogeochemical processes-and their responses to environmental change-is critical. However, identifying consistent drivers of belowground diversity and abundance for some soil organisms at large spatial scales remains problematic. Here we investigate a major guild, the ectomycorrhizal fungi, across European forests at a spatial scale and resolution that is-to our knowledge-unprecedented, to explore key biotic and abiotic predictors of ectomycorrhizal diversity and to identify dominant responses and thresholds for change across complex environmental gradients. We show the effect of 38 host, environment, climate and geographical variables on ectomycorrhizal diversity, and define thresholds of community change for key variables. We quantify host specificity and reveal plasticity in functional traits involved in soil foraging across gradients. We conclude that environmental and host factors explain most of the variation in ectomycorrhizal diversity, that the environmental thresholds used as major ecosystem assessment tools need adjustment and that the importance of belowground specificity and plasticity has previously been underappreciated.

Large-Scale 3D Printing: The Way Forward

Science.gov (United States)

Jassmi, Hamad Al; Najjar, Fady Al; Ismail Mourad, Abdel-Hamid

2018-03-01

Research on small-scale 3D printing has rapidly evolved, where numerous industrial products have been tested and successfully applied. Nonetheless, research on large-scale 3D printing, directed to large-scale applications such as construction and automotive manufacturing, yet demands a great a great deal of efforts. Large-scale 3D printing is considered an interdisciplinary topic and requires establishing a blended knowledge base from numerous research fields including structural engineering, materials science, mechatronics, software engineering, artificial intelligence and architectural engineering. This review article summarizes key topics of relevance to new research trends on large-scale 3D printing, particularly pertaining (1) technological solutions of additive construction (i.e. the 3D printers themselves), (2) materials science challenges, and (3) new design opportunities.

Data and performance profiles applying an adaptive truncation criterion, within linesearch-based truncated Newton methods, in large scale nonconvex optimization

Directory of Open Access Journals (Sweden)

Andrea Caliciotti

2018-04-01

Full Text Available In this paper, we report data and experiments related to the research article entitled “An adaptive truncation criterion, for linesearch-based truncated Newton methods in large scale nonconvex optimization” by Caliciotti et al. [1]. In particular, in Caliciotti et al. [1], large scale unconstrained optimization problems are considered by applying linesearch-based truncated Newton methods. In this framework, a key point is the reduction of the number of inner iterations needed, at each outer iteration, to approximately solving the Newton equation. A novel adaptive truncation criterion is introduced in Caliciotti et al. [1] to this aim. Here, we report the details concerning numerical experiences over a commonly used test set, namely CUTEst (Gould et al., 2015 [2]. Moreover, comparisons are reported in terms of performance profiles (Dolan and Moré, 2002 [3], adopting different parameters settings. Finally, our linesearch-based scheme is compared with a renowned trust region method, namely TRON (Lin and Moré, 1999 [4].

Growth Limits in Large Scale Networks

DEFF Research Database (Denmark)

Knudsen, Thomas Phillip

limitations. The rising complexity of network management with the convergence of communications platforms is shown as problematic for both automatic management feasibility and for manpower resource management. In the fourth step the scope is extended to include the present society with the DDN project as its......The Subject of large scale networks is approached from the perspective of the network planner. An analysis of the long term planning problems is presented with the main focus on the changing requirements for large scale networks and the potential problems in meeting these requirements. The problems...... the fundamental technological resources in network technologies are analysed for scalability. Here several technological limits to continued growth are presented. The third step involves a survey of major problems in managing large scale networks given the growth of user requirements and the technological...

Accelerating sustainability in large-scale facilities

CERN Multimedia

Marina Giampietro

2011-01-01

Scientific research centres and large-scale facilities are intrinsically energy intensive, but how can big science improve its energy management and eventually contribute to the environmental cause with new cleantech? CERN’s commitment to providing tangible answers to these questions was sealed in the first workshop on energy management for large scale scientific infrastructures held in Lund, Sweden, on the 13-14 October.   Participants at the energy management for large scale scientific infrastructures workshop. The workshop, co-organised with the European Spallation Source (ESS) and  the European Association of National Research Facilities (ERF), tackled a recognised need for addressing energy issues in relation with science and technology policies. It brought together more than 150 representatives of Research Infrastrutures (RIs) and energy experts from Europe and North America. “Without compromising our scientific projects, we can ...

Large scale tracking algorithms

Energy Technology Data Exchange (ETDEWEB)

Hansen, Ross L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Love, Joshua Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Melgaard, David Kennett [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Karelitz, David B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pitts, Todd Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zollweg, Joshua David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Anderson, Dylan Z. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nandy, Prabal [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Whitlow, Gary L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bender, Daniel A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Byrne, Raymond Harry [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-01-01

Low signal-to-noise data processing algorithms for improved detection, tracking, discrimination and situational threat assessment are a key research challenge. As sensor technologies progress, the number of pixels will increase signi cantly. This will result in increased resolution, which could improve object discrimination, but unfortunately, will also result in a significant increase in the number of potential targets to track. Many tracking techniques, like multi-hypothesis trackers, suffer from a combinatorial explosion as the number of potential targets increase. As the resolution increases, the phenomenology applied towards detection algorithms also changes. For low resolution sensors, "blob" tracking is the norm. For higher resolution data, additional information may be employed in the detection and classfication steps. The most challenging scenarios are those where the targets cannot be fully resolved, yet must be tracked and distinguished for neighboring closely spaced objects. Tracking vehicles in an urban environment is an example of such a challenging scenario. This report evaluates several potential tracking algorithms for large-scale tracking in an urban environment.

Large scale reflood test

International Nuclear Information System (INIS)

Hirano, Kemmei; Murao, Yoshio

1980-01-01

The large-scale reflood test with a view to ensuring the safety of light water reactors was started in fiscal 1976 based on the special account act for power source development promotion measures by the entrustment from the Science and Technology Agency. Thereafter, to establish the safety of PWRs in loss-of-coolant accidents by joint international efforts, the Japan-West Germany-U.S. research cooperation program was started in April, 1980. Thereupon, the large-scale reflood test is now included in this program. It consists of two tests using a cylindrical core testing apparatus for examining the overall system effect and a plate core testing apparatus for testing individual effects. Each apparatus is composed of the mock-ups of pressure vessel, primary loop, containment vessel and ECCS. The testing method, the test results and the research cooperation program are described. (J.P.N.)

Large-area perovskite nanowire arrays fabricated by large-scale roll-to-roll micro-gravure printing and doctor blading

Science.gov (United States)

Hu, Qiao; Wu, Han; Sun, Jia; Yan, Donghang; Gao, Yongli; Yang, Junliang

2016-02-01

Organic-inorganic hybrid halide perovskite nanowires (PNWs) show great potential applications in electronic and optoelectronic devices such as solar cells, field-effect transistors and photodetectors. It is very meaningful to fabricate ordered, large-area PNW arrays and greatly accelerate their applications and commercialization in electronic and optoelectronic devices. Herein, highly oriented and ultra-long methylammonium lead iodide (CH3NH3PbI3) PNW array thin films were fabricated by large-scale roll-to-roll (R2R) micro-gravure printing and doctor blading in ambient environments (humility ~45%, temperature ~28 °C), which produced PNW lengths as long as 15 mm. Furthermore, photodetectors based on these PNWs were successfully fabricated on both silicon oxide (SiO2) and flexible polyethylene terephthalate (PET) substrates and showed moderate performance. This study provides low-cost, large-scale techniques to fabricate large-area PNW arrays with great potential applications in flexible electronic and optoelectronic devices.Organic-inorganic hybrid halide perovskite nanowires (PNWs) show great potential applications in electronic and optoelectronic devices such as solar cells, field-effect transistors and photodetectors. It is very meaningful to fabricate ordered, large-area PNW arrays and greatly accelerate their applications and commercialization in electronic and optoelectronic devices. Herein, highly oriented and ultra-long methylammonium lead iodide (CH3NH3PbI3) PNW array thin films were fabricated by large-scale roll-to-roll (R2R) micro-gravure printing and doctor blading in ambient environments (humility ~45%, temperature ~28 °C), which produced PNW lengths as long as 15 mm. Furthermore, photodetectors based on these PNWs were successfully fabricated on both silicon oxide (SiO2) and flexible polyethylene terephthalate (PET) substrates and showed moderate performance. This study provides low-cost, large-scale techniques to fabricate large-area PNW arrays

Presenting an Approach for Conducting Knowledge Architecture within Large-Scale Organizations.

Science.gov (United States)

Varaee, Touraj; Habibi, Jafar; Mohaghar, Ali

2015-01-01

Knowledge architecture (KA) establishes the basic groundwork for the successful implementation of a short-term or long-term knowledge management (KM) program. An example of KA is the design of a prototype before a new vehicle is manufactured. Due to a transformation to large-scale organizations, the traditional architecture of organizations is undergoing fundamental changes. This paper explores the main strengths and weaknesses in the field of KA within large-scale organizations and provides a suitable methodology and supervising framework to overcome specific limitations. This objective was achieved by applying and updating the concepts from the Zachman information architectural framework and the information architectural methodology of enterprise architecture planning (EAP). The proposed solution may be beneficial for architects in knowledge-related areas to successfully accomplish KM within large-scale organizations. The research method is descriptive; its validity is confirmed by performing a case study and polling the opinions of KA experts.

A Combined Eulerian-Lagrangian Data Representation for Large-Scale Applications.

Science.gov (United States)

Sauer, Franz; Xie, Jinrong; Ma, Kwan-Liu

2017-10-01

The Eulerian and Lagrangian reference frames each provide a unique perspective when studying and visualizing results from scientific systems. As a result, many large-scale simulations produce data in both formats, and analysis tasks that simultaneously utilize information from both representations are becoming increasingly popular. However, due to their fundamentally different nature, drawing correlations between these data formats is a computationally difficult task, especially in a large-scale setting. In this work, we present a new data representation which combines both reference frames into a joint Eulerian-Lagrangian format. By reorganizing Lagrangian information according to the Eulerian simulation grid into a "unit cell" based approach, we can provide an efficient out-of-core means of sampling, querying, and operating with both representations simultaneously. We also extend this design to generate multi-resolution subsets of the full data to suit the viewer's needs and provide a fast flow-aware trajectory construction scheme. We demonstrate the effectiveness of our method using three large-scale real world scientific datasets and provide insight into the types of performance gains that can be achieved.

Large Scale Cosmological Anomalies and Inhomogeneous Dark Energy

Directory of Open Access Journals (Sweden)

Leandros Perivolaropoulos

2014-01-01

Full Text Available A wide range of large scale observations hint towards possible modifications on the standard cosmological model which is based on a homogeneous and isotropic universe with a small cosmological constant and matter. These observations, also known as “cosmic anomalies” include unexpected Cosmic Microwave Background perturbations on large angular scales, large dipolar peculiar velocity flows of galaxies (“bulk flows”, the measurement of inhomogenous values of the fine structure constant on cosmological scales (“alpha dipole” and other effects. The presence of the observational anomalies could either be a large statistical fluctuation in the context of ΛCDM or it could indicate a non-trivial departure from the cosmological principle on Hubble scales. Such a departure is very much constrained by cosmological observations for matter. For dark energy however there are no significant observational constraints for Hubble scale inhomogeneities. In this brief review I discuss some of the theoretical models that can naturally lead to inhomogeneous dark energy, their observational constraints and their potential to explain the large scale cosmic anomalies.

Large-scale patterns in Rayleigh-Benard convection

International Nuclear Information System (INIS)

Hardenberg, J. von; Parodi, A.; Passoni, G.; Provenzale, A.; Spiegel, E.A.

2008-01-01

Rayleigh-Benard convection at large Rayleigh number is characterized by the presence of intense, vertically moving plumes. Both laboratory and numerical experiments reveal that the rising and descending plumes aggregate into separate clusters so as to produce large-scale updrafts and downdrafts. The horizontal scales of the aggregates reported so far have been comparable to the horizontal extent of the containers, but it has not been clear whether that represents a limitation imposed by domain size. In this work, we present numerical simulations of convection at sufficiently large aspect ratio to ascertain whether there is an intrinsic saturation scale for the clustering process when that ratio is large enough. From a series of simulations of Rayleigh-Benard convection with Rayleigh numbers between 10 5 and 10 8 and with aspect ratios up to 12π, we conclude that the clustering process has a finite horizontal saturation scale with at most a weak dependence on Rayleigh number in the range studied

Decision support for large-scale remediation strategies by fused urban metabolism and life cycle assessment

DEFF Research Database (Denmark)

Ohms, Pernille; Andersen, Camilla; Landgren, Mathilde

2018-01-01

Purpose: This paper seeks to identify the most environmental friendly way of conducting a refurbishment of Broendby Strand, with focus on PCB remediation. The actual identification is conducted by comparing four remediation techniques using urban metabolism fused with life cycle assessment (UM......-LCA) in combination with information relating to cost and efficiency of the compared techniques. The methodological goal of our paper is to test UM-LCA as a decision support tool and discuss application of the method in relation to large refurbishment projects. Methods: To assess the environmental performance of PCB......-remediation techniques, the UM-LCA method was applied. By combining UM and LCA methodologies, the total environmental impact potentials of the remediation techniques were calculated. To build an inventory for each technique, we contacted and interviewed experts and studied existing literature, cases, and projects...

On the relationship between large-scale climate modes and regional synoptic patterns that drive Victorian rainfall

Science.gov (United States)

Verdon-Kidd, D. C.; Kiem, A. S.

2009-04-01

In this paper regional (synoptic) and large-scale climate drivers of rainfall are investigated for Victoria, Australia. A non-linear classification methodology known as self-organizing maps (SOM) is used to identify 20 key regional synoptic patterns, which are shown to capture a range of significant synoptic features known to influence the climate of the region. Rainfall distributions are assigned to each of the 20 patterns for nine rainfall stations located across Victoria, resulting in a clear distinction between wet and dry synoptic types at each station. The influence of large-scale climate modes on the frequency and timing of the regional synoptic patterns is also investigated. This analysis revealed that phase changes in the El Niño Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD) and/or the Southern Annular Mode (SAM) are associated with a shift in the relative frequency of wet and dry synoptic types on an annual to inter-annual timescale. In addition, the relative frequency of synoptic types is shown to vary on a multi-decadal timescale, associated with changes in the Inter-decadal Pacific Oscillation (IPO). Importantly, these results highlight the potential to utilise the link between the regional synoptic patterns derived in this study and large-scale climate modes to improve rainfall forecasting for Victoria, both in the short- (i.e. seasonal) and long-term (i.e. decadal/multi-decadal scale). In addition, the regional and large-scale climate drivers identified in this study provide a benchmark by which the performance of Global Climate Models (GCMs) may be assessed.

Methodology for a GIS-based damage assessment for researchers following large scale disasters

Science.gov (United States)

Crawford, Patrick Shane

research field. Along with visually mapping the data, geometric calculations can be conducted on the data to give the viewer more information about the damage. In Chapter 4, a tornado damage contour for Moore, Oklahoma following the May 20, 2013 tornado is shown. This damage contour was created in GIS based on the Enhanced Fujita (EF) damage scale, and gives the viewer an easily understood picture of the extent and distribution of the tornado. This thesis aims to describe a foundational groundwork for activities that are performed in the GIS-based damage assessment procedure and provide uses for the damage assessment as well as research being conducted on how to use the data collected from these assessments. This will allow researchers to conduct a highly adaptable, rapid GIS-based damage assessment of their own.

The effect of various parameters of large scale radio propagation models on improving performance mobile communications

Science.gov (United States)

Pinem, M.; Fauzi, R.

2018-02-01

One technique for ensuring continuity of wireless communication services and keeping a smooth transition on mobile communication networks is the soft handover technique. In the Soft Handover (SHO) technique the inclusion and reduction of Base Station from the set of active sets is determined by initiation triggers. One of the initiation triggers is based on the strong reception signal. In this paper we observed the influence of parameters of large-scale radio propagation models to improve the performance of mobile communications. The observation parameters for characterizing the performance of the specified mobile system are Drop Call, Radio Link Degradation Rate and Average Size of Active Set (AS). The simulated results show that the increase in altitude of Base Station (BS) Antenna and Mobile Station (MS) Antenna contributes to the improvement of signal power reception level so as to improve Radio Link quality and increase the average size of Active Set and reduce the average Drop Call rate. It was also found that Hata’s propagation model contributed significantly to improvements in system performance parameters compared to Okumura’s propagation model and Lee’s propagation model.

Evaluating the Performance of the Goddard Multi-Scale Modeling Framework against GPM, TRMM and CloudSat/CALIPSO Products

Science.gov (United States)

Chern, J. D.; Tao, W. K.; Lang, S. E.; Matsui, T.; Mohr, K. I.

2014-12-01

Four six-month (March-August 2014) experiments with the Goddard Multi-scale Modeling Framework (MMF) were performed to study the impacts of different Goddard one-moment bulk microphysical schemes and large-scale forcings on the performance of the MMF. Recently a new Goddard one-moment bulk microphysics with four-ice classes (cloud ice, snow, graupel, and frozen drops/hail) has been developed based on cloud-resolving model simulations with large-scale forcings from field campaign observations. The new scheme has been successfully implemented to the MMF and two MMF experiments were carried out with this new scheme and the old three-ice classes (cloud ice, snow graupel) scheme. The MMF has global coverage and can rigorously evaluate microphysics performance for different cloud regimes. The results show MMF with the new scheme outperformed the old one. The MMF simulations are also strongly affected by the interaction between large-scale and cloud-scale processes. Two MMF sensitivity experiments with and without nudging large-scale forcings to those of ERA-Interim reanalysis were carried out to study the impacts of large-scale forcings. The model simulated mean and variability of surface precipitation, cloud types, cloud properties such as cloud amount, hydrometeors vertical profiles, and cloud water contents, etc. in different geographic locations and climate regimes are evaluated against GPM, TRMM, CloudSat/CALIPSO satellite observations. The Goddard MMF has also been coupled with the Goddard Satellite Data Simulation Unit (G-SDSU), a system with multi-satellite, multi-sensor, and multi-spectrum satellite simulators. The statistics of MMF simulated radiances and backscattering can be directly compared with satellite observations to assess the strengths and/or deficiencies of MMF simulations and provide guidance on how to improve the MMF and microphysics.

Manufacturing test of large scale hollow capsule and long length cladding in the large scale oxide dispersion strengthened (ODS) martensitic steel

International Nuclear Information System (INIS)

Narita, Takeshi; Ukai, Shigeharu; Kaito, Takeji; Ohtsuka, Satoshi; Fujiwara, Masayuki

2004-04-01

Mass production capability of oxide dispersion strengthened (ODS) martensitic steel cladding (9Cr) has being evaluated in the Phase II of the Feasibility Studies on Commercialized Fast Reactor Cycle System. The cost for manufacturing mother tube (raw materials powder production, mechanical alloying (MA) by ball mill, canning, hot extrusion, and machining) is a dominant factor in the total cost for manufacturing ODS ferritic steel cladding. In this study, the large-sale 9Cr-ODS martensitic steel mother tube which is made with a large-scale hollow capsule, and long length claddings were manufactured, and the applicability of these processes was evaluated. Following results were obtained in this study. (1) Manufacturing the large scale mother tube in the dimension of 32 mm OD, 21 mm ID, and 2 m length has been successfully carried out using large scale hollow capsule. This mother tube has a high degree of accuracy in size. (2) The chemical composition and the micro structure of the manufactured mother tube are similar to the existing mother tube manufactured by a small scale can. And the remarkable difference between the bottom and top sides in the manufactured mother tube has not been observed. (3) The long length cladding has been successfully manufactured from the large scale mother tube which was made using a large scale hollow capsule. (4) For reducing the manufacturing cost of the ODS steel claddings, manufacturing process of the mother tubes using a large scale hollow capsules is promising. (author)

Infrastructure for large-scale quality-improvement projects: early lessons from North Carolina Improving Performance in Practice.

Science.gov (United States)

Newton, Warren P; Lefebvre, Ann; Donahue, Katrina E; Bacon, Thomas; Dobson, Allen

2010-01-01

Little is known regarding how to accomplish large-scale health care improvement. Our goal is to improve the quality of chronic disease care in all primary care practices throughout North Carolina. Methods for improvement include (1) common quality measures and shared data system; (2) rapid cycle improvement principles; (3) quality-improvement consultants (QICs), or practice facilitators; (4) learning networks; and (5) alignment of incentives. We emphasized a community-based strategy and developing a statewide infrastructure. Results are reported from the first 2 years of the North Carolina Improving Performance in Practice (IPIP) project. A coalition was formed to include professional societies, North Carolina AHEC, Community Care of North Carolina, insurers, and other organizations. Wave One started with 18 practices in 2 of 9 regions of the state. Quality-improvement consultants recruited practices. Over 80 percent of practices attended all quarterly regional meetings. In 9 months, almost all diabetes measures improved, and a bundled asthma measure improved from 33 to 58 percent. Overall, the magnitude of improvement was clinically and statistically significant (P = .001). Quality improvements were maintained on review 1 year later. Wave Two has spread to 103 practices in all 9 regions of the state, with 42 additional practices beginning the enrollment process. Large-scale health care quality improvement is feasible, when broadly supported by statewide leadership and community infrastructure. Practice-collected data and lack of a control group are limitations of the study design. Future priorities include maintaining improved sustainability for practices and communities. Our long-term goal is to transform all 2000 primary-care practices in our state.

Just enough inflation. Power spectrum modifications at large scales

International Nuclear Information System (INIS)

Cicoli, Michele; Downes, Sean

2014-07-01

We show that models of 'just enough' inflation, where the slow-roll evolution lasted only 50-60 e-foldings, feature modifications of the CMB power spectrum at large angular scales. We perform a systematic and model-independent analysis of any possible non-slow-roll background evolution prior to the final stage of slow-roll inflation. We find a high degree of universality since most common backgrounds like fast-roll evolution, matter or radiation-dominance give rise to a power loss at large angular scales and a peak together with an oscillatory behaviour at scales around the value of the Hubble parameter at the beginning of slow-roll inflation. Depending on the value of the equation of state parameter, different pre-inflationary epochs lead instead to an enhancement of power at low-l, and so seem disfavoured by recent observational hints for a lack of CMB power at l< or similar 40. We also comment on the importance of initial conditions and the possibility to have multiple pre-inflationary stages.

Superconducting materials for large scale applications

International Nuclear Information System (INIS)

Dew-Hughes, D.

1975-01-01

Applications of superconductors capable of carrying large current densities in large-scale electrical devices are examined. Discussions are included on critical current density, superconducting materials available, and future prospects for improved superconducting materials. (JRD)

Presenting an Approach for Conducting Knowledge Architecture within Large-Scale Organizations

Science.gov (United States)

Varaee, Touraj; Habibi, Jafar; Mohaghar, Ali

2015-01-01

Knowledge architecture (KA) establishes the basic groundwork for the successful implementation of a short-term or long-term knowledge management (KM) program. An example of KA is the design of a prototype before a new vehicle is manufactured. Due to a transformation to large-scale organizations, the traditional architecture of organizations is undergoing fundamental changes. This paper explores the main strengths and weaknesses in the field of KA within large-scale organizations and provides a suitable methodology and supervising framework to overcome specific limitations. This objective was achieved by applying and updating the concepts from the Zachman information architectural framework and the information architectural methodology of enterprise architecture planning (EAP). The proposed solution may be beneficial for architects in knowledge-related areas to successfully accomplish KM within large-scale organizations. The research method is descriptive; its validity is confirmed by performing a case study and polling the opinions of KA experts. PMID:25993414

Survey of large-scale solar water heaters installed in Taiwan, China

Energy Technology Data Exchange (ETDEWEB)

Chang Keh-Chin; Lee Tsong-Sheng; Chung Kung-Ming [Cheng Kung Univ., Tainan (China); Lien Ya-Feng; Lee Chine-An [Cheng Kung Univ. Research and Development Foundation, Tainan (China)

2008-07-01

Almost all the solar collectors installed in Taiwan, China were used for production of hot water for homeowners (residential systems), in which the area of solar collectors is less than 10 square meters. From 2001 to 2006, there were only 39 large-scale systems (defined as the area of solar collectors being over 100 m{sup 2}) installed. Their utilization purposes are for rooming house (dormitory), swimming pool, restaurant, and manufacturing process. A comprehensive survey of those large-scale solar water heaters was conducted in 2006. The objectives of the survey were to asses the systems' performance and to have the feedback from the individual users. It is found that lack of experience in system design and maintenance are the key factors for reliable operation of a system. For further promotion of large-scale solar water heaters in Taiwan, a more compressive program on a system design for manufacturing process should be conducted. (orig.)

Analysis using large-scale ringing data

Directory of Open Access Journals (Sweden)

Baillie, S. R.

2004-06-01

Full Text Available Birds are highly mobile organisms and there is increasing evidence that studies at large spatial scales are needed if we are to properly understand their population dynamics. While classical metapopulation models have rarely proved useful for birds, more general metapopulation ideas involving collections of populations interacting within spatially structured landscapes are highly relevant (Harrison, 1994. There is increasing interest in understanding patterns of synchrony, or lack of synchrony, between populations and the environmental and dispersal mechanisms that bring about these patterns (Paradis et al., 2000. To investigate these processes we need to measure abundance, demographic rates and dispersal at large spatial scales, in addition to gathering data on relevant environmental variables. There is an increasing realisation that conservation needs to address rapid declines of common and widespread species (they will not remain so if such trends continue as well as the management of small populations that are at risk of extinction. While the knowledge needed to support the management of small populations can often be obtained from intensive studies in a few restricted areas, conservation of widespread species often requires information on population trends and processes measured at regional, national and continental scales (Baillie, 2001. While management prescriptions for widespread populations may initially be developed from a small number of local studies or experiments, there is an increasing need to understand how such results will scale up when applied across wider areas. There is also a vital role for monitoring at large spatial scales both in identifying such population declines and in assessing population recovery. Gathering data on avian abundance and demography at large spatial scales usually relies on the efforts of large numbers of skilled volunteers. Volunteer studies based on ringing (for example Constant Effort Sites [CES

Large-scale influences in near-wall turbulence.

Science.gov (United States)

Hutchins, Nicholas; Marusic, Ivan

2007-03-15

Hot-wire data acquired in a high Reynolds number facility are used to illustrate the need for adequate scale separation when considering the coherent structure in wall-bounded turbulence. It is found that a large-scale motion in the log region becomes increasingly comparable in energy to the near-wall cycle as the Reynolds number increases. Through decomposition of fluctuating velocity signals, it is shown that this large-scale motion has a distinct modulating influence on the small-scale energy (akin to amplitude modulation). Reassessment of DNS data, in light of these results, shows similar trends, with the rate and intensity of production due to the near-wall cycle subject to a modulating influence from the largest-scale motions.

Computational challenges of large-scale, long-time, first-principles molecular dynamics

International Nuclear Information System (INIS)

Kent, P R C

2008-01-01

Plane wave density functional calculations have traditionally been able to use the largest available supercomputing resources. We analyze the scalability of modern projector-augmented wave implementations to identify the challenges in performing molecular dynamics calculations of large systems containing many thousands of electrons. Benchmark calculations on the Cray XT4 demonstrate that global linear-algebra operations are the primary reason for limited parallel scalability. Plane-wave related operations can be made sufficiently scalable. Improving parallel linear-algebra performance is an essential step to reaching longer timescales in future large-scale molecular dynamics calculations

Special educaction and rewiews in the municipality of large scale Sobral (CE

Directory of Open Access Journals (Sweden)

Ana Paula Lima Barbosa Cardoso

2012-11-01

Full Text Available This article aims to discuss and analyze the participation of students with disabilities in public schools of the city of Sobral-CE in the assessment scale developed in that context. It follows a case study, a qualitative approach, conducted within the Department of Education and two municipal schools; the highest and lowest IDEB results (2009. The data collection instruments: analysis of documents, interviews and observation, and content analysis. The theoretical framework discusses the large-scale evaluation in the brazilian context in conjunction with the literature on the evaluation of teaching for students with disabilities. We describe the landscape of education in general sobralense and also data on special education. The research results discussed two cases of large-scale evaluation that occurred in that municipality: municipal evaluation and Proof Brazil. Regarding the first, the subjects affirms the participation of students with disabilities through a mechanism that prevents these results affect other students, are called "children of the shore." In Proof Brazil, the subjects again reported the participation of these students in national testing. It's criticizing the appropriateness of that instrument to assess this particular student body, suggesting the need of developping more "relevant" ones. Finally, it appears that the large-scale evaluation calls into question the process of schooling experienced by pupils with disabilities in Sobral-CE, showing the challenges and difficulties of the actions of school inclusion proposals in that context.

Large-Scale Astrophysical Visualization on Smartphones

Science.gov (United States)

Becciani, U.; Massimino, P.; Costa, A.; Gheller, C.; Grillo, A.; Krokos, M.; Petta, C.

2011-07-01

Nowadays digital sky surveys and long-duration, high-resolution numerical simulations using high performance computing and grid systems produce multidimensional astrophysical datasets in the order of several Petabytes. Sharing visualizations of such datasets within communities and collaborating research groups is of paramount importance for disseminating results and advancing astrophysical research. Moreover educational and public outreach programs can benefit greatly from novel ways of presenting these datasets by promoting understanding of complex astrophysical processes, e.g., formation of stars and galaxies. We have previously developed VisIVO Server, a grid-enabled platform for high-performance large-scale astrophysical visualization. This article reviews the latest developments on VisIVO Web, a custom designed web portal wrapped around VisIVO Server, then introduces VisIVO Smartphone, a gateway connecting VisIVO Web and data repositories for mobile astrophysical visualization. We discuss current work and summarize future developments.

Large-scale hydrogen combustion experiments: Volume 2, Data plots: Final report

International Nuclear Information System (INIS)

Thompson, R.T.; Torok, R.C.; Randall, D.S.; Sullivan, J.S.; Thompson, L.B.; Haugh, J.J.

1988-10-01

Forty large-scale experiments to investigate the combustion behavior of hydrogen during postulated degraded core accidents were conducted in a 16 m (52 ft) diameter sphere. The performance of safety related equipment and cable also was examined. Combustion was initiated by thermal igniters in both premixed hydrogen air-steam atmospheres and during the continuous injection of hydrogen and steam. The effects of steam, igniter location, water sprays, fans and injection rates were studied. Measurements were made of gas concentrations, combustion pressures, temperatures and heat fluxes. Burn fractions and flame speeds also were determined. Near-infrared seeing cameras permitted direct observation of the hydrogen burns. Combustion pressures and temperatures in premixed atmospheres with hydrogen concentrations up to 13 vol% (steam saturated) were less than the theoretical maximum values. Multiple deflagrations were not encountered during continuous hydrogen injection with pre-activated igniters. Moderate pressure rises resulted from diffusion flames. These flames generally were found above the source. Combustion results have been compared to smaller scale experiments. Several safety related equipment items exhibited degraded performance after a number of tests. Most cable samples passed their electrical checks at the end of the test series. These experiments confirm the effectiveness of the deliberate ignition approach to controlling hydrogen. They also provide data for validating computer codes used to predict hydrogen combustion during degraded core accidents, and for assessing the performance of safety related equipment in such environments

DECOVALEX III III/BENCHPAR PROJECTS. Approaches to Upscaling Thermal-Hydro-Mechanical Processes in a Fractured Rock. Mass and its Significance for Large-Scale Repository Performance Assessment. Summary of Findings. Report of BMT2/WP3

Energy Technology Data Exchange (ETDEWEB)

Andersson, Johan (comp.) [JA Streamflow AB, Aelvsjoe (Sweden); Staub, Isabelle (comp.) [Golder Associates AB, Stockholm (Sweden); Knight, Les (comp.) [Nirex UK Ltd, Oxon (United Kingdom)

2005-02-15

The Benchmark Test 2 of DECOVALEX III and Work Package 3 of BENCHPAR concerns the upscaling Thermal (T), Hydrological (H) and Mechanical (M) processes in a fractured rock mass and its significance for large-scale repository performance assessment. The work is primarily concerned with the extent to which various thermo-hydro-mechanical couplings in a fractured rock mass adjacent to a repository are significant in terms of solute transport typically calculated in large-scale repository performance assessments. Since the presence of even quite small fractures may control the hydraulic, mechanical and coupled hydromechanical behaviour of the rock mass, a key of the work has been to explore the extent to which these can be upscaled and represented by 'equivalent' continuum properties appropriate PA calculations. From these general aims the BMT was set-up as a numerical study of a large scale reference problem. Analysing this reference problem should: help explore how different means of simplifying the geometrical detail of a site, with its implications on model parameters, ('upscaling') impacts model predictions of relevance to repository performance, explore to what extent the THM-coupling needs to be considered in relation to PA-measures, compare the uncertainties in upscaling (both to uncertainty on how to upscale or uncertainty that arises due to the upscaling processes) and consideration of THM couplings with the inherent uncertainty and spatial variability of the site specific data. Furthermore, it has been an essential component of the work that individual teams not only produce numerical results but are forced to make their own judgements and to provide the proper justification for their conclusions based on their analysis. It should also be understood that conclusions drawn will partly be specific to the problem analysed, in particular as it mainly concerns a 2D application. This means that specific conclusions may have limited applicability

Performance of lap splices in large-scale column specimens affected by ASR and/or DEF-extension phase.

Science.gov (United States)

2015-03-01

A large experimental program, consisting of the design, construction, curing, exposure, and structural load : testing of 16 large-scale column specimens with a critical lap splice region that were influenced by varying : stages of alkali-silica react...

Experimental Investigation of a Large-Scale Low-Boom Inlet Concept

Science.gov (United States)

Hirt, Stefanie M.; Chima, Rodrick V.; Vyas, Manan A.; Wayman, Thomas R.; Conners, Timothy R.; Reger, Robert W.

2011-01-01

A large-scale low-boom inlet concept was tested in the NASA Glenn Research Center 8- x 6- foot Supersonic Wind Tunnel. The purpose of this test was to assess inlet performance, stability and operability at various Mach numbers and angles of attack. During this effort, two models were tested: a dual stream inlet designed to mimic potential aircraft flight hardware integrating a high-flow bypass stream; and a single stream inlet designed to study a configuration with a zero-degree external cowl angle and to permit surface visualization of the vortex generator flow on the internal centerbody surface. During the course of the test, the low-boom inlet concept was demonstrated to have high recovery, excellent buzz margin, and high operability. This paper will provide an overview of the setup, show a brief comparison of the dual stream and single stream inlet results, and examine the dual stream inlet characteristics.

Initial condition effects on large scale structure in numerical simulations of plane mixing layers

Science.gov (United States)

McMullan, W. A.; Garrett, S. J.

2016-01-01

In this paper, Large Eddy Simulations are performed on the spatially developing plane turbulent mixing layer. The simulated mixing layers originate from initially laminar conditions. The focus of this research is on the effect of the nature of the imposed fluctuations on the large-scale spanwise and streamwise structures in the flow. Two simulations are performed; one with low-level three-dimensional inflow fluctuations obtained from pseudo-random numbers, the other with physically correlated fluctuations of the same magnitude obtained from an inflow generation technique. Where white-noise fluctuations provide the inflow disturbances, no spatially stationary streamwise vortex structure is observed, and the large-scale spanwise turbulent vortical structures grow continuously and linearly. These structures are observed to have a three-dimensional internal geometry with branches and dislocations. Where physically correlated provide the inflow disturbances a "streaky" streamwise structure that is spatially stationary is observed, with the large-scale turbulent vortical structures growing with the square-root of time. These large-scale structures are quasi-two-dimensional, on top of which the secondary structure rides. The simulation results are discussed in the context of the varying interpretations of mixing layer growth that have been postulated. Recommendations are made concerning the data required from experiments in order to produce accurate numerical simulation recreations of real flows.

Large-scale sulfolane-impacted soil remediation at a gas plant

Energy Technology Data Exchange (ETDEWEB)

Lavoie, G.; Rockwell, K. [Biogenie Inc., Calgary, AB (Canada)

2006-07-01

A large-scale sulfolane-impacted soil remediation project at a gas plant in central Alberta was discussed. The plant was operational from the 1960s to present and the former operation involved the Sulfinol process which resulted in groundwater contamination. In 2005, the client wanted to address the sources area. The Sulfinol process has been used since the 1960s to remove hydrogen sulfide and other corrosive gases from natural gas streams. Sulfinol uses sulfolane and diisopropanolamine. Sulfolane is toxic, non-volatile, and water soluble. The presentation also addressed the remediation objectives and an additional site assessment that was conducted to better delineate the sulfolane and sulphur plume, as well as metals. The findings of the ESA and site specific challenges were presented. These challenges included: plant operation concerns; numerous overhead, surface, and underground structures; large volume of impacted material, limited space available on site; several types of contaminants; and time required to perform the overall work. Next, the sulfolane remediation strategy was discussed including advantages and results of the investigation. Last, the results of the project were presented. It was found that there were no recordable safety incidents and that all remedial objectives were achieved. tabs., figs.

Selective vulnerability related to aging in large-scale resting brain networks.

Science.gov (United States)

Zhang, Hong-Ying; Chen, Wen-Xin; Jiao, Yun; Xu, Yao; Zhang, Xiang-Rong; Wu, Jing-Tao

2014-01-01

Normal aging is associated with cognitive decline. Evidence indicates that large-scale brain networks are affected by aging; however, it has not been established whether aging has equivalent effects on specific large-scale networks. In the present study, 40 healthy subjects including 22 older (aged 60-80 years) and 18 younger (aged 22-33 years) adults underwent resting-state functional MRI scanning. Four canonical resting-state networks, including the default mode network (DMN), executive control network (ECN), dorsal attention network (DAN) and salience network, were extracted, and the functional connectivities in these canonical networks were compared between the younger and older groups. We found distinct, disruptive alterations present in the large-scale aging-related resting brain networks: the ECN was affected the most, followed by the DAN. However, the DMN and salience networks showed limited functional connectivity disruption. The visual network served as a control and was similarly preserved in both groups. Our findings suggest that the aged brain is characterized by selective vulnerability in large-scale brain networks. These results could help improve our understanding of the mechanism of degeneration in the aging brain. Additional work is warranted to determine whether selective alterations in the intrinsic networks are related to impairments in behavioral performance.

PKI security in large-scale healthcare networks.

Science.gov (United States)

Mantas, Georgios; Lymberopoulos, Dimitrios; Komninos, Nikos

2012-06-01

During the past few years a lot of PKI (Public Key Infrastructures) infrastructures have been proposed for healthcare networks in order to ensure secure communication services and exchange of data among healthcare professionals. However, there is a plethora of challenges in these healthcare PKI infrastructures. Especially, there are a lot of challenges for PKI infrastructures deployed over large-scale healthcare networks. In this paper, we propose a PKI infrastructure to ensure security in a large-scale Internet-based healthcare network connecting a wide spectrum of healthcare units geographically distributed within a wide region. Furthermore, the proposed PKI infrastructure facilitates the trust issues that arise in a large-scale healthcare network including multi-domain PKI infrastructures.

Large-Scale Assessment of Change in Student Achievement: Dutch Primary School Students' Results on Written Division in 1997 and 2004 as an Example

Science.gov (United States)

van den Heuvel-Panhuizen, Marja; Robitzsch, Alexander; Treffers, Adri; Koller, Olaf

2009-01-01

This article discusses large-scale assessment of change in student achievement and takes the study by Hickendorff, Heiser, Van Putten, and Verhelst (2009) as an example. This study compared the achievement of students in the Netherlands in 1997 and 2004 on written division problems. Based on this comparison, they claim that there is a performance…

Emerging large-scale solar heating applications

International Nuclear Information System (INIS)

Wong, W.P.; McClung, J.L.

2009-01-01

Currently the market for solar heating applications in Canada is dominated by outdoor swimming pool heating, make-up air pre-heating and domestic water heating in homes, commercial and institutional buildings. All of these involve relatively small systems, except for a few air pre-heating systems on very large buildings. Together these applications make up well over 90% of the solar thermal collectors installed in Canada during 2007. These three applications, along with the recent re-emergence of large-scale concentrated solar thermal for generating electricity, also dominate the world markets. This paper examines some emerging markets for large scale solar heating applications, with a focus on the Canadian climate and market. (author)

Emerging large-scale solar heating applications

Energy Technology Data Exchange (ETDEWEB)

Wong, W.P.; McClung, J.L. [Science Applications International Corporation (SAIC Canada), Ottawa, Ontario (Canada)

2009-07-01

Currently the market for solar heating applications in Canada is dominated by outdoor swimming pool heating, make-up air pre-heating and domestic water heating in homes, commercial and institutional buildings. All of these involve relatively small systems, except for a few air pre-heating systems on very large buildings. Together these applications make up well over 90% of the solar thermal collectors installed in Canada during 2007. These three applications, along with the recent re-emergence of large-scale concentrated solar thermal for generating electricity, also dominate the world markets. This paper examines some emerging markets for large scale solar heating applications, with a focus on the Canadian climate and market. (author)

Performance regression manager for large scale systems

Science.gov (United States)

Faraj, Daniel A.

2017-08-01

System and computer program product to perform an operation comprising generating, based on a first output generated by a first execution instance of a command, a first output file specifying a value of at least one performance metric, wherein the first output file is formatted according to a predefined format, comparing the value of the at least one performance metric in the first output file to a value of the performance metric in a second output file, the second output file having been generated based on a second output generated by a second execution instance of the command, and outputting for display an indication of a result of the comparison of the value of the at least one performance metric of the first output file to the value of the at least one performance metric of the second output file.

Iodine oxides in large-scale THAI tests

International Nuclear Information System (INIS)

Funke, F.; Langrock, G.; Kanzleiter, T.; Poss, G.; Fischer, K.; Kühnel, A.; Weber, G.; Allelein, H.-J.

2012-01-01

Highlights: ► Iodine oxide particles were produced from gaseous iodine and ozone. ► Ozone replaced the effect of ionizing radiation in the large-scale THAI facility. ► The mean diameter of the iodine oxide particles was about 0.35 μm. ► Particle formation was faster than the chemical reaction between iodine and ozone. ► Deposition of iodine oxide particles was slow in the absence of other aerosols. - Abstract: The conversion of gaseous molecular iodine into iodine oxide aerosols has significant relevance in the understanding of the fission product iodine volatility in a LWR containment during severe accidents. In containment, the high radiation field caused by fission products released from the reactor core induces radiolytic oxidation into iodine oxides. To study the characteristics and the behaviour of iodine oxides in large scale, two THAI tests Iod-13 and Iod-14 were performed, simulating radiolytic oxidation of molecular iodine by reaction of iodine with ozone, with ozone injected from an ozone generator. The observed iodine oxides form submicron particles with mean volume-related diameters of about 0.35 μm and show low deposition rates in the THAI tests performed in the absence of other nuclear aerosols. Formation of iodine aerosols from gaseous precursors iodine and ozone is fast as compared to their chemical interaction. The current approach in empirical iodine containment behaviour models in severe accidents, including the radiolytic production of I 2 -oxidizing agents followed by the I 2 oxidation itself, is confirmed by these THAI tests.

Referred Students' Performance on the Reynolds Intellectual Assessment Scales and the Wechsler Intelligence Scale for Children--Fourth Edition

Science.gov (United States)

Edwards, Oliver W.; Paulin, Rachel V.

2007-01-01

This study investigates the convergent relations of the Reynolds Intellectual Assessment Scales (RIAS) and the Wechsler Intelligence Scale for Children--Fourth Edition (WISC-IV). Data from counterbalanced administrations of each instrument to 48 elementary school students referred for psychoeducational testing were examined. Analysis of the 96…

Large-scale regions of antimatter

International Nuclear Information System (INIS)

Grobov, A. V.; Rubin, S. G.

2015-01-01

Amodified mechanism of the formation of large-scale antimatter regions is proposed. Antimatter appears owing to fluctuations of a complex scalar field that carries a baryon charge in the inflation era

Large-scale regions of antimatter

Energy Technology Data Exchange (ETDEWEB)

Grobov, A. V., E-mail: alexey.grobov@gmail.com; Rubin, S. G., E-mail: sgrubin@mephi.ru [National Research Nuclear University MEPhI (Russian Federation)

2015-07-15

Amodified mechanism of the formation of large-scale antimatter regions is proposed. Antimatter appears owing to fluctuations of a complex scalar field that carries a baryon charge in the inflation era.

Environmental implications of large-scale adoption of wind power: a scenario-based life cycle assessment

International Nuclear Information System (INIS)

Arvesen, Anders; Hertwich, Edgar G

2011-01-01

We investigate the potential environmental impacts of a large-scale adoption of wind power to meet up to 22% of the world’s growing electricity demand. The analysis builds on life cycle assessments of generic onshore and offshore wind farms, meant to represent average conditions for global deployment of wind power. We scale unit-based findings to estimate aggregated emissions of building, operating and decommissioning wind farms toward 2050, taking into account changes in the electricity mix in manufacturing. The energy scenarios investigated are the International Energy Agency’s BLUE scenarios. We estimate 1.7–2.6 Gt CO 2 -eq climate change, 2.1–3.2 Mt N-eq marine eutrophication, 9.2–14 Mt NMVOC photochemical oxidant formation, and 9.5–15 Mt SO 2 -eq terrestrial acidification impact category indicators due to global wind power in 2007–50. Assuming lifetimes 5 yr longer than reference, the total climate change indicator values are reduced by 8%. In the BLUE Map scenario, construction of new capacity contributes 64%, and repowering of existing capacity 38%, to total cumulative greenhouse gas emissions. The total emissions of wind electricity range between 4% and 14% of the direct emissions of the replaced fossil-fueled power plants. For all impact categories, the indirect emissions of displaced fossil power are larger than the total emissions caused by wind power.

Assessing Human Modifications to Floodplains using Large-Scale Hydrogeomorphic Floodplain Modeling

Science.gov (United States)

Morrison, R. R.; Scheel, K.; Nardi, F.; Annis, A.

2017-12-01

Human modifications to floodplains for water resource and flood management purposes have significantly transformed river-floodplain connectivity dynamics in many watersheds. Bridges, levees, reservoirs, shifts in land use, and other hydraulic engineering works have altered flow patterns and caused changes in the timing and extent of floodplain inundation processes. These hydrogeomorphic changes have likely resulted in negative impacts to aquatic habitat and ecological processes. The availability of large-scale topographic datasets at high resolution provide an opportunity for detecting anthropogenic impacts by means of geomorphic mapping. We have developed and are implementing a methodology for comparing a hydrogeomorphic floodplain mapping technique to hydraulically-modeled floodplain boundaries to estimate floodplain loss due to human activities. Our hydrogeomorphic mapping methodology assumes that river valley morphology intrinsically includes information on flood-driven erosion and depositional phenomena. We use a digital elevation model-based algorithm to identify the floodplain as the area of the fluvial corridor laying below water reference levels, which are estimated using a simplified hydrologic model. Results from our hydrogeomorphic method are compared to hydraulically-derived flood zone maps and spatial datasets of levee protected-areas to explore where water management features, such as levees, have changed floodplain dynamics and landscape features. Parameters associated with commonly used F-index functions are quantified and analyzed to better understand how floodplain areas have been reduced within a basin. Preliminary results indicate that the hydrogeomorphic floodplain model is useful for quickly delineating floodplains at large watershed scales, but further analyses are needed to understand the caveats for using the model in determining floodplain loss due to levees. We plan to continue this work by exploring the spatial dependencies of the F

The Climate Potentials and Side-Effects of Large-Scale terrestrial CO2 Removal - Insights from Quantitative Model Assessments

Science.gov (United States)

Boysen, L.; Heck, V.; Lucht, W.; Gerten, D.

2015-12-01

Terrestrial carbon dioxide removal (tCDR) through dedicated biomass plantations is considered as one climate engineering (CE) option if implemented at large-scale. While the risks and costs are supposed to be small, the effectiveness depends strongly on spatial and temporal scales of implementation. Based on simulations with a dynamic global vegetation model (LPJmL) we comprehensively assess the effectiveness, biogeochemical side-effects and tradeoffs from an earth system-analytic perspective. We analyzed systematic land-use scenarios in which all, 25%, or 10% of natural and/or agricultural areas are converted to tCDR plantations including the assumption that biomass plantations are established once the 2°C target is crossed in a business-as-usual climate change trajectory. The resulting tCDR potentials in year 2100 include the net accumulated annual biomass harvests and changes in all land carbon pools. We find that only the most spatially excessive, and thus undesirable, scenario would be capable to restore the 2° target by 2100 under continuing high emissions (with a cooling of 3.02°C). Large-scale biomass plantations covering areas between 1.1 - 4.2 Gha would produce a climate reduction potential of 0.8 - 1.4°C. tCDR plantations at smaller scales do not build up enough biomass over this considered period and the potentials to achieve global warming reductions are substantially lowered to no more than 0.5-0.6°C. Finally, we demonstrate that the (non-economic) costs for the Earth system include negative impacts on the water cycle and on ecosystems, which are already under pressure due to both land use change and climate change. Overall, tCDR may lead to a further transgression of land- and water-related planetary boundaries while not being able to set back the crossing of the planetary boundary for climate change. tCDR could still be considered in the near-future mitigation portfolio if implemented on small scales on wisely chosen areas.

Large-Scale Analysis of Art Proportions

DEFF Research Database (Denmark)

Jensen, Karl Kristoffer

2014-01-01

While literature often tries to impute mathematical constants into art, this large-scale study (11 databases of paintings and photos, around 200.000 items) shows a different truth. The analysis, consisting of the width/height proportions, shows a value of rarely if ever one (square) and with majo......While literature often tries to impute mathematical constants into art, this large-scale study (11 databases of paintings and photos, around 200.000 items) shows a different truth. The analysis, consisting of the width/height proportions, shows a value of rarely if ever one (square...

The Expanded Large Scale Gap Test

Science.gov (United States)

1987-03-01

NSWC TR 86-32 DTIC THE EXPANDED LARGE SCALE GAP TEST BY T. P. LIDDIARD D. PRICE RESEARCH AND TECHNOLOGY DEPARTMENT ’ ~MARCH 1987 Ap~proved for public...arises, to reduce the spread in the LSGT 50% gap value.) The worst charges, such as those with the highest or lowest densities, the largest re-pressed...Arlington, VA 22217 PE 62314N INS3A 1 RJ14E31 7R4TBK 11 TITLE (Include Security CIlmsilficatiorn The Expanded Large Scale Gap Test . 12. PEIRSONAL AUTHOR() T

Large-scale runoff generation - parsimonious parameterisation using high-resolution topography

Science.gov (United States)

Gong, L.; Halldin, S.; Xu, C.-Y.

2011-08-01

World water resources have primarily been analysed by global-scale hydrological models in the last decades. Runoff generation in many of these models are based on process formulations developed at catchments scales. The division between slow runoff (baseflow) and fast runoff is primarily governed by slope and spatial distribution of effective water storage capacity, both acting at very small scales. Many hydrological models, e.g. VIC, account for the spatial storage variability in terms of statistical distributions; such models are generally proven to perform well. The statistical approaches, however, use the same runoff-generation parameters everywhere in a basin. The TOPMODEL concept, on the other hand, links the effective maximum storage capacity with real-world topography. Recent availability of global high-quality, high-resolution topographic data makes TOPMODEL attractive as a basis for a physically-based runoff-generation algorithm at large scales, even if its assumptions are not valid in flat terrain or for deep groundwater systems. We present a new runoff-generation algorithm for large-scale hydrology based on TOPMODEL concepts intended to overcome these problems. The TRG (topography-derived runoff generation) algorithm relaxes the TOPMODEL equilibrium assumption so baseflow generation is not tied to topography. TRG only uses the topographic index to distribute average storage to each topographic index class. The maximum storage capacity is proportional to the range of topographic index and is scaled by one parameter. The distribution of storage capacity within large-scale grid cells is obtained numerically through topographic analysis. The new topography-derived distribution function is then inserted into a runoff-generation framework similar VIC's. Different basin parts are parameterised by different storage capacities, and different shapes of the storage-distribution curves depend on their topographic characteristics. The TRG algorithm is driven by the

Falsire: CSNI project for fracture analyses of large-scale international reference experiments (Phase 1). Comparison report

International Nuclear Information System (INIS)

1994-01-01

A summary of the recently completed Phase I of the Project for Fracture Analysis of Large-Scale International Reference Experiments (Project FALSIRE) is presented. Project FALSIRE was created by the Fracture Assessment Group (FAG) of Principal Working Group No. 3 (PWG/3) of the OECD/NEA Committee on the Safety of Nuclear Installations (CSNI), formed to evaluate fracture prediction capabilities currently used in safety assessments of nuclear vessel components. The aim of the Project FALSIRE was to assess various fracture methodologies through interpretive analyses of selected large-scale fracture experiments. The six experiments used in Project FALSIRE (performed in the Federal Republic of Germany, Japan, the United Kingdom, and the U.S.A.) were designed to examine various aspects of crack growth in reactor pressure vessel (RPV) steels under pressurized-thermal-shock (PTS) loading conditions. The analysis techniques employed by the participants included engineering and finite-element methods, which were combined with Jr fracture methodology and the French local approach. For each experiment, analysis results provided estimates of variables such as crack growth, crack-mouth-opening displacement, temperature, stress, strain, and applied J and K values. A comparative assessment and discussion of the analysis results are presented; also, the current status of the entire results data base is summarized. Some conclusions concerning predictive capabilities of selected ductile fracture methodologies, as applied to RPVs subjected to PTS loading, are given, and recommendations for future development of fracture methodologies are made

Solving large scale structure in ten easy steps with COLA

Energy Technology Data Exchange (ETDEWEB)

Tassev, Svetlin [Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Princeton, NJ 08544 (United States); Zaldarriaga, Matias [School of Natural Sciences, Institute for Advanced Study, Olden Lane, Princeton, NJ 08540 (United States); Eisenstein, Daniel J., E-mail: stassev@cfa.harvard.edu, E-mail: matiasz@ias.edu, E-mail: deisenstein@cfa.harvard.edu [Center for Astrophysics, Harvard University, 60 Garden Street, Cambridge, MA 02138 (United States)

2013-06-01

We present the COmoving Lagrangian Acceleration (COLA) method: an N-body method for solving for Large Scale Structure (LSS) in a frame that is comoving with observers following trajectories calculated in Lagrangian Perturbation Theory (LPT). Unlike standard N-body methods, the COLA method can straightforwardly trade accuracy at small-scales in order to gain computational speed without sacrificing accuracy at large scales. This is especially useful for cheaply generating large ensembles of accurate mock halo catalogs required to study galaxy clustering and weak lensing, as those catalogs are essential for performing detailed error analysis for ongoing and future surveys of LSS. As an illustration, we ran a COLA-based N-body code on a box of size 100 Mpc/h with particles of mass ≈ 5 × 10{sup 9}M{sub s}un/h. Running the code with only 10 timesteps was sufficient to obtain an accurate description of halo statistics down to halo masses of at least 10{sup 11}M{sub s}un/h. This is only at a modest speed penalty when compared to mocks obtained with LPT. A standard detailed N-body run is orders of magnitude slower than our COLA-based code. The speed-up we obtain with COLA is due to the fact that we calculate the large-scale dynamics exactly using LPT, while letting the N-body code solve for the small scales, without requiring it to capture exactly the internal dynamics of halos. Achieving a similar level of accuracy in halo statistics without the COLA method requires at least 3 times more timesteps than when COLA is employed.

Large scale and big data processing and management

CERN Document Server

Sakr, Sherif

2014-01-01

Large Scale and Big Data: Processing and Management provides readers with a central source of reference on the data management techniques currently available for large-scale data processing. Presenting chapters written by leading researchers, academics, and practitioners, it addresses the fundamental challenges associated with Big Data processing tools and techniques across a range of computing environments.The book begins by discussing the basic concepts and tools of large-scale Big Data processing and cloud computing. It also provides an overview of different programming models and cloud-bas

The role of natural analogues in performance assessment

International Nuclear Information System (INIS)

Ewing, R.C.

1992-01-01

One of the unique and scientifically most challenging aspects of nuclear waste isolation is the extrapolation of short-term laboratory data (hours to years) to the long time periods (10 3 - 10 5 years) required by regulatory agencies for performance assessment. The direct verification of these extrapolations is not possible, but methods must be developed to demonstrate compliance with government regulations and to satisfy the lay public that there is a demonstrable and reasonable basis for accepting the long-term extrapolations. Natural systems provide perhaps the only means of partial verification, as well as data that may be used directly in the models that are used in the extrapolation. Natural systems provide data on very large spatial (m to km) and temporal (10 3 - 10 8 years) scales, and in highly complex terranes in which unknown synergisms may effect radionuclide migration. This paper reviews the application (and most importantly, the limitations) of data from natural analogue systems to the verification of performance assessments

Base Station Placement Algorithm for Large-Scale LTE Heterogeneous Networks.

Science.gov (United States)

Lee, Seungseob; Lee, SuKyoung; Kim, Kyungsoo; Kim, Yoon Hyuk

2015-01-01

Data traffic demands in cellular networks today are increasing at an exponential rate, giving rise to the development of heterogeneous networks (HetNets), in which small cells complement traditional macro cells by extending coverage to indoor areas. However, the deployment of small cells as parts of HetNets creates a key challenge for operators' careful network planning. In particular, massive and unplanned deployment of base stations can cause high interference, resulting in highly degrading network performance. Although different mathematical modeling and optimization methods have been used to approach various problems related to this issue, most traditional network planning models are ill-equipped to deal with HetNet-specific characteristics due to their focus on classical cellular network designs. Furthermore, increased wireless data demands have driven mobile operators to roll out large-scale networks of small long term evolution (LTE) cells. Therefore, in this paper, we aim to derive an optimum network planning algorithm for large-scale LTE HetNets. Recently, attempts have been made to apply evolutionary algorithms (EAs) to the field of radio network planning, since they are characterized as global optimization methods. Yet, EA performance often deteriorates rapidly with the growth of search space dimensionality. To overcome this limitation when designing optimum network deployments for large-scale LTE HetNets, we attempt to decompose the problem and tackle its subcomponents individually. Particularly noting that some HetNet cells have strong correlations due to inter-cell interference, we propose a correlation grouping approach in which cells are grouped together according to their mutual interference. Both the simulation and analytical results indicate that the proposed solution outperforms the random-grouping based EA as well as an EA that detects interacting variables by monitoring the changes in the objective function algorithm in terms of system

Large scale cluster computing workshop

International Nuclear Information System (INIS)

Dane Skow; Alan Silverman

2002-01-01

Recent revolutions in computer hardware and software technologies have paved the way for the large-scale deployment of clusters of commodity computers to address problems heretofore the domain of tightly coupled SMP processors. Near term projects within High Energy Physics and other computing communities will deploy clusters of scale 1000s of processors and be used by 100s to 1000s of independent users. This will expand the reach in both dimensions by an order of magnitude from the current successful production facilities. The goals of this workshop were: (1) to determine what tools exist which can scale up to the cluster sizes foreseen for the next generation of HENP experiments (several thousand nodes) and by implication to identify areas where some investment of money or effort is likely to be needed. (2) To compare and record experimences gained with such tools. (3) To produce a practical guide to all stages of planning, installing, building and operating a large computing cluster in HENP. (4) To identify and connect groups with similar interest within HENP and the larger clustering community

On the validity of self-report assessment of cognitive abilities: Attentional control scale associations with cognitive performance, emotional adjustment, and personality.

Science.gov (United States)

Williams, Paula G; Rau, Holly K; Suchy, Yana; Thorgusen, Sommer R; Smith, Timothy W

2017-05-01

Individual differences in attentional control involve the ability to voluntarily direct, shift, and sustain attention. In studies of the role of attentional control in emotional adjustment, social relationships, and vulnerability to the effects of stress, self-report questionnaires are commonly used to measure this construct. Yet, convincing evidence of the association between self-report scales and actual cognitive performance has not been demonstrated. Across 2 independent samples, we examined associations between self-reported attentional control (Attentional Control Scale; ACS), self-reported emotional adjustment, Five-Factor Model personality traits (NEO Personality Inventory-Revised) and performance measures of attentional control. Study 1 examined behavioral performance on the Attention Network Test (ANT; Fan, McCandliss, Sommer, Raz, & Posner, 2002) and the Modified Switching Task (MST; Suchy & Kosson, 2006) in a large sample (n = 315) of healthy young adults. Study 2 (n = 78) examined behavioral performance on standardized neuropsychological tests of attention, including Conner's Continuous Performance Test-II and subtests from the Wechsler Adult Intelligence Scales, Third Edition (WAIS-III; Psychological Corporation, 1997) and Delis-Kaplan Executive Function System (D-KEFS; Delis, Kaplan, & Kramer, 2001). Results indicated that the ACS was largely unrelated to behavioral performance measures of attentional control but was significantly associated with emotional adjustment, neuroticism, and conscientiousness. These findings suggest that although self-reported attentional control may be a useful construct, researchers using the ACS should exercise caution in interpreting it as a proxy for actual cognitive ability or performance. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Large-Scale Agriculture and Outgrower Schemes in Ethiopia

DEFF Research Database (Denmark)

Wendimu, Mengistu Assefa

, the impact of large-scale agriculture and outgrower schemes on productivity, household welfare and wages in developing countries is highly contentious. Chapter 1 of this thesis provides an introduction to the study, while also reviewing the key debate in the contemporary land ‘grabbing’ and historical large...... sugarcane outgrower scheme on household income and asset stocks. Chapter 5 examines the wages and working conditions in ‘formal’ large-scale and ‘informal’ small-scale irrigated agriculture. The results in Chapter 2 show that moisture stress, the use of untested planting materials, and conflict over land...... commands a higher wage than ‘formal’ large-scale agriculture, while rather different wage determination mechanisms exist in the two sectors. Human capital characteristics (education and experience) partly explain the differences in wages within the formal sector, but play no significant role...

Study of multi-functional precision optical measuring system for large scale equipment

Science.gov (United States)

Jiang, Wei; Lao, Dabao; Zhou, Weihu; Zhang, Wenying; Jiang, Xingjian; Wang, Yongxi

2017-10-01

The effective application of high performance measurement technology can greatly improve the large-scale equipment manufacturing ability. Therefore, the geometric parameters measurement, such as size, attitude and position, requires the measurement system with high precision, multi-function, portability and other characteristics. However, the existing measuring instruments, such as laser tracker, total station, photogrammetry system, mostly has single function, station moving and other shortcomings. Laser tracker needs to work with cooperative target, but it can hardly meet the requirement of measurement in extreme environment. Total station is mainly used for outdoor surveying and mapping, it is hard to achieve the demand of accuracy in industrial measurement. Photogrammetry system can achieve a wide range of multi-point measurement, but the measuring range is limited and need to repeatedly move station. The paper presents a non-contact opto-electronic measuring instrument, not only it can work by scanning the measurement path but also measuring the cooperative target by tracking measurement. The system is based on some key technologies, such as absolute distance measurement, two-dimensional angle measurement, automatically target recognition and accurate aiming, precision control, assembly of complex mechanical system and multi-functional 3D visualization software. Among them, the absolute distance measurement module ensures measurement with high accuracy, and the twodimensional angle measuring module provides precision angle measurement. The system is suitable for the case of noncontact measurement of large-scale equipment, it can ensure the quality and performance of large-scale equipment throughout the process of manufacturing and improve the manufacturing ability of large-scale and high-end equipment.

Mixing and scale affect moving bed biofilm reactor (MBBR) performance

NARCIS (Netherlands)

Kamstra, Andries; Blom, Ewout; Terjesen, Bendik Fyhn

2017-01-01

Moving Bed Biofilm Reactors (MBBR) are used increasingly in closed systems for farming of fish. Scaling, i.e. design of units of increasing size, is an important issue in general bio-reactor design since mixing behaviour will differ between small and large scale. Research is mostly performed on

Large Scale Processes and Extreme Floods in Brazil

Science.gov (United States)

Ribeiro Lima, C. H.; AghaKouchak, A.; Lall, U.

2016-12-01

Persistent large scale anomalies in the atmospheric circulation and ocean state have been associated with heavy rainfall and extreme floods in water basins of different sizes across the world. Such studies have emerged in the last years as a new tool to improve the traditional, stationary based approach in flood frequency analysis and flood prediction. Here we seek to advance previous studies by evaluating the dominance of large scale processes (e.g. atmospheric rivers/moisture transport) over local processes (e.g. local convection) in producing floods. We consider flood-prone regions in Brazil as case studies and the role of large scale climate processes in generating extreme floods in such regions is explored by means of observed streamflow, reanalysis data and machine learning methods. The dynamics of the large scale atmospheric circulation in the days prior to the flood events are evaluated based on the vertically integrated moisture flux and its divergence field, which are interpreted in a low-dimensional space as obtained by machine learning techniques, particularly supervised kernel principal component analysis. In such reduced dimensional space, clusters are obtained in order to better understand the role of regional moisture recycling or teleconnected moisture in producing floods of a given magnitude. The convective available potential energy (CAPE) is also used as a measure of local convection activities. We investigate for individual sites the exceedance probability in which large scale atmospheric fluxes dominate the flood process. Finally, we analyze regional patterns of floods and how the scaling law of floods with drainage area responds to changes in the climate forcing mechanisms (e.g. local vs large scale).

Integrating weather and geotechnical monitoring data for assessing the stability of large scale surface mining operations

Directory of Open Access Journals (Sweden)

Steiakakis Chrysanthos

2016-01-01

Full Text Available The geotechnical challenges for safe slope design in large scale surface mining operations are enormous. Sometimes one degree of slope inclination can significantly reduce the overburden to ore ratio and therefore dramatically improve the economics of the operation, while large scale slope failures may have a significant impact on human lives. Furthermore, adverse weather conditions, such as high precipitation rates, may unfavorably affect the already delicate balance between operations and safety. Geotechnical, weather and production parameters should be systematically monitored and evaluated in order to safely operate such pits. Appropriate data management, processing and storage are critical to ensure timely and informed decisions.

Status of large scale wind turbine technology development abroad?

Institute of Scientific and Technical Information of China (English)

Ye LI; Lei DUAN

2016-01-01

To facilitate the large scale (multi-megawatt) wind turbine development in China, the foreign e?orts and achievements in the area are reviewed and summarized. Not only the popular horizontal axis wind turbines on-land but also the o?shore wind turbines, vertical axis wind turbines, airborne wind turbines, and shroud wind turbines are discussed. The purpose of this review is to provide a comprehensive comment and assessment about the basic work principle, economic aspects, and environmental impacts of turbines.

Computing in Large-Scale Dynamic Systems

NARCIS (Netherlands)

Pruteanu, A.S.

2013-01-01

Software applications developed for large-scale systems have always been difficult to de- velop due to problems caused by the large number of computing devices involved. Above a certain network size (roughly one hundred), necessary services such as code updating, topol- ogy discovery and data

Vibration amplitude rule study for rotor under large time scale

International Nuclear Information System (INIS)

Yang Xuan; Zuo Jianli; Duan Changcheng

2014-01-01

The rotor is an important part of the rotating machinery; its vibration performance is one of the important factors affecting the service life. This paper presents both theoretical analyses and experimental demonstrations of the vibration rule of the rotor under large time scales. The rule can be used for the service life estimation of the rotor. (authors)

Experimental study of detonation of large-scale powder-droplet-vapor mixtures

Science.gov (United States)

Bai, C.-H.; Wang, Y.; Xue, K.; Wang, L.-F.

2018-05-01

Large-scale experiments were carried out to investigate the detonation performance of a 1600-m3 ternary cloud consisting of aluminum powder, fuel droplets, and vapor, which were dispersed by a central explosive in a cylindrically stratified configuration. High-frame-rate video cameras and pressure gauges were used to analyze the large-scale explosive dispersal of the mixture and the ensuing blast wave generated by the detonation of the cloud. Special attention was focused on the effect of the descending motion of the charge on the detonation performance of the dispersed ternary cloud. The charge was parachuted by an ensemble of apparatus from the designated height in order to achieve the required terminal velocity when the central explosive was detonated. A descending charge with a terminal velocity of 32 m/s produced a cloud with discernably increased concentration compared with that dispersed from a stationary charge, the detonation of which hence generates a significantly enhanced blast wave beyond the scaled distance of 6 m/kg^{1/3}. The results also show the influence of the descending motion of the charge on the jetting phenomenon and the distorted shock front.

Fires in large scale ventilation systems

International Nuclear Information System (INIS)

Gregory, W.S.; Martin, R.A.; White, B.W.; Nichols, B.D.; Smith, P.R.; Leslie, I.H.; Fenton, D.L.; Gunaji, M.V.; Blythe, J.P.

1991-01-01

This paper summarizes the experience gained simulating fires in large scale ventilation systems patterned after ventilation systems found in nuclear fuel cycle facilities. The series of experiments discussed included: (1) combustion aerosol loading of 0.61x0.61 m HEPA filters with the combustion products of two organic fuels, polystyrene and polymethylemethacrylate; (2) gas dynamic and heat transport through a large scale ventilation system consisting of a 0.61x0.61 m duct 90 m in length, with dampers, HEPA filters, blowers, etc.; (3) gas dynamic and simultaneous transport of heat and solid particulate (consisting of glass beads with a mean aerodynamic diameter of 10μ) through the large scale ventilation system; and (4) the transport of heat and soot, generated by kerosene pool fires, through the large scale ventilation system. The FIRAC computer code, designed to predict fire-induced transients in nuclear fuel cycle facility ventilation systems, was used to predict the results of experiments (2) through (4). In general, the results of the predictions were satisfactory. The code predictions for the gas dynamics, heat transport, and particulate transport and deposition were within 10% of the experimentally measured values. However, the code was less successful in predicting the amount of soot generation from kerosene pool fires, probably due to the fire module of the code being a one-dimensional zone model. The experiments revealed a complicated three-dimensional combustion pattern within the fire room of the ventilation system. Further refinement of the fire module within FIRAC is needed. (orig.)

Large-scale Complex IT Systems

OpenAIRE

Sommerville, Ian; Cliff, Dave; Calinescu, Radu; Keen, Justin; Kelly, Tim; Kwiatkowska, Marta; McDermid, John; Paige, Richard

2011-01-01

This paper explores the issues around the construction of large-scale complex systems which are built as 'systems of systems' and suggests that there are fundamental reasons, derived from the inherent complexity in these systems, why our current software engineering methods and techniques cannot be scaled up to cope with the engineering challenges of constructing such systems. It then goes on to propose a research and education agenda for software engineering that identifies the major challen...

Large-scale complex IT systems

OpenAIRE

Sommerville, Ian; Cliff, Dave; Calinescu, Radu; Keen, Justin; Kelly, Tim; Kwiatkowska, Marta; McDermid, John; Paige, Richard

2012-01-01

12 pages, 2 figures This paper explores the issues around the construction of large-scale complex systems which are built as 'systems of systems' and suggests that there are fundamental reasons, derived from the inherent complexity in these systems, why our current software engineering methods and techniques cannot be scaled up to cope with the engineering challenges of constructing such systems. It then goes on to propose a research and education agenda for software engineering that ident...

IP over optical multicasting for large-scale video delivery

Science.gov (United States)

Jin, Yaohui; Hu, Weisheng; Sun, Weiqiang; Guo, Wei

2007-11-01

In the IPTV systems, multicasting will play a crucial role in the delivery of high-quality video services, which can significantly improve bandwidth efficiency. However, the scalability and the signal quality of current IPTV can barely compete with the existing broadcast digital TV systems since it is difficult to implement large-scale multicasting with end-to-end guaranteed quality of service (QoS) in packet-switched IP network. China 3TNet project aimed to build a high performance broadband trial network to support large-scale concurrent streaming media and interactive multimedia services. The innovative idea of 3TNet is that an automatic switched optical networks (ASON) with the capability of dynamic point-to-multipoint (P2MP) connections replaces the conventional IP multicasting network in the transport core, while the edge remains an IP multicasting network. In this paper, we will introduce the network architecture and discuss challenges in such IP over Optical multicasting for video delivery.

First Mile Challenges for Large-Scale IoT

KAUST Repository

Bader, Ahmed; Elsawy, Hesham; Gharbieh, Mohammad; Alouini, Mohamed-Slim; Adinoyi, Abdulkareem; Alshaalan, Furaih

2017-01-01

The Internet of Things is large-scale by nature. This is not only manifested by the large number of connected devices, but also by the sheer scale of spatial traffic intensity that must be accommodated, primarily in the uplink direction. To that end

Large-scale Estimates of Leaf Area Index from Active Remote Sensing Laser Altimetry

Science.gov (United States)

Hopkinson, C.; Mahoney, C.

2016-12-01

Leaf area index (LAI) is a key parameter that describes the spatial distribution of foliage within forest canopies which in turn control numerous relationships between the ground, canopy, and atmosphere. The retrieval of LAI has demonstrated success by in-situ (digital) hemispherical photography (DHP) and airborne laser scanning (ALS) data; however, field and ALS acquisitions are often spatially limited (100's km2) and costly. Large-scale (>1000's km2) retrievals have been demonstrated by optical sensors, however, accuracies remain uncertain due to the sensor's inability to penetrate the canopy. The spaceborne Geoscience Laser Altimeter System (GLAS) provides a possible solution in retrieving large-scale derivations whilst simultaneously penetrating the canopy. LAI retrieved by multiple DHP from 6 Australian sites, representing a cross-section of Australian ecosystems, were employed to model ALS LAI, which in turn were used to infer LAI from GLAS data at 5 other sites. An optimally filtered GLAS dataset was then employed in conjunction with a host of supplementary data to build a Random Forest (RF) model to infer predictions (and uncertainties) of LAI at a 250 m resolution across the forested regions of Australia. Predictions were validated against ALS-based LAI from 20 sites (R2=0.64, RMSE=1.1 m2m-2); MODIS-based LAI were also assessed against these sites (R2=0.30, RMSE=1.78 m2m-2) to demonstrate the strength of GLAS-based predictions. The large-scale nature of current predictions was also leveraged to demonstrate large-scale relationships of LAI with other environmental characteristics, such as: canopy height, elevation, and slope. The need for such wide-scale quantification of LAI is key in the assessment and modification of forest management strategies across Australia. Such work also assists Australia's Terrestrial Ecosystem Research Network, in fulfilling their government issued mandates.

High-Performance Carbon Dioxide Electrocatalytic Reduction by Easily Fabricated Large-Scale Silver Nanowire Arrays.

Science.gov (United States)

Luan, Chuhao; Shao, Yang; Lu, Qi; Gao, Shenghan; Huang, Kai; Wu, Hui; Yao, Kefu

2018-05-17

An efficient and selective catalyst is in urgent need for carbon dioxide electroreduction and silver is one of the promising candidates with affordable costs. Here we fabricated large-scale vertically standing Ag nanowire arrays with high crystallinity and electrical conductivity as carbon dioxide electroreduction catalysts by a simple nanomolding method that was usually considered not feasible for metallic crystalline materials. A great enhancement of current densities and selectivity for CO at moderate potentials was achieved. The current density for CO ( j co ) of Ag nanowire array with 200 nm in diameter was more than 2500 times larger than that of Ag foil at an overpotential of 0.49 V with an efficiency over 90%. The origin of enhanced performances are attributed to greatly increased electrochemically active surface area (ECSA) and higher intrinsic activity compared to those of polycrystalline Ag foil. More low-coordinated sites on the nanowires which can stabilize the CO 2 intermediate better are responsible for the high intrinsic activity. In addition, the impact of surface morphology that induces limited mass transportation on reaction selectivity and efficiency of nanowire arrays with different diameters was also discussed.

Contributions to large scale and performance tests of the ATLAS online software

International Nuclear Information System (INIS)

Badescu, E.; Caprini, M.

2003-01-01

One of the sub-system of the Trigger/DAQ system of the future ATLAS experiment is the Online Software system. It encompasses the functionality needed to configure, control and monitor the DAQ. Its architecture is based on a component structure described in the ATLAS Trigger/DAQ technical proposal. Online Software is responsible for control, supervision and internal communication, excluding the event data flow. For the final ATLAS experiment in 2006 it is expected that it will have to control up to 1000 processors. The core components are the run control, process manager, configuration database, inter process communication, message reporting system and information exchange system. The auxiliary components, namely resource manager, online bookkeeper and the integrated graphical user interface were in use for tests. All the components are unit tested for functionality, fault tolerance, performance and scalability. Extended functionality tests are performed at CERN and remote institutes before each official release. The test objective was the verification of the scalability of the system to a configuration containing a large number of nodes. The aim was to study the interaction between the components, to identify critical areas and to investigate the variation and optimization of online system parameters. The timing of the data acquisition transition phases were recorded and analysed. The information on all processes and their relationships, the run control hierarchy in the online system as well as startup and shutdown dependencies are defined in the configuration database data file. Timing measurements were performed for the transitions shown in the paper and defined as follows: Setup: start online server infrastructure; Close: remove online infrastructure; Boot: start all supervised processes; Shutdown: stop all supervised processes; Cold start: start the supervised processes and go to the Running state; Cold stop: reverse of the cold start phase; Luke warm start

On the Use of Educational Numbers: Comparative Constructions of Hierarchies by Means of Large-Scale Assessments

Directory of Open Access Journals (Sweden)

Daniel Pettersson

2016-01-01

later the growing importance of transnational agencies and international, regional and national assessments. How to reference this article Pettersson, D., Popkewitz, T. S., & Lindblad, S. (2016. On the Use of Educational Numbers: Comparative Constructions of Hierarchies by Means of Large-Scale Assessments. Espacio, Tiempo y Educación, 3(1, 177-202. doi: http://dx.doi.org/10.14516/ete.2016.003.001.10

Prospects for large scale electricity storage in Denmark

DEFF Research Database (Denmark)

Krog Ekman, Claus; Jensen, Søren Højgaard

2010-01-01

In a future power systems with additional wind power capacity there will be an increased need for large scale power management as well as reliable balancing and reserve capabilities. Different technologies for large scale electricity storage provide solutions to the different challenges arising w...

Large-Scale Structure and Hyperuniformity of Amorphous Ices

Science.gov (United States)

Martelli, Fausto; Torquato, Salvatore; Giovambattista, Nicolas; Car, Roberto

2017-09-01

We investigate the large-scale structure of amorphous ices and transitions between their different forms by quantifying their large-scale density fluctuations. Specifically, we simulate the isothermal compression of low-density amorphous ice (LDA) and hexagonal ice to produce high-density amorphous ice (HDA). Both HDA and LDA are nearly hyperuniform; i.e., they are characterized by an anomalous suppression of large-scale density fluctuations. By contrast, in correspondence with the nonequilibrium phase transitions to HDA, the presence of structural heterogeneities strongly suppresses the hyperuniformity and the system becomes hyposurficial (devoid of "surface-area fluctuations"). Our investigation challenges the largely accepted "frozen-liquid" picture, which views glasses as structurally arrested liquids. Beyond implications for water, our findings enrich our understanding of pressure-induced structural transformations in glasses.

Hydrogen-combustion analyses of large-scale tests

International Nuclear Information System (INIS)

Gido, R.G.; Koestel, A.

1986-01-01

This report uses results of the large-scale tests with turbulence performed by the Electric Power Research Institute at the Nevada Test Site to evaluate hydrogen burn-analysis procedures based on lumped-parameter codes like COMPARE-H2 and associated burn-parameter models. The test results: (1) confirmed, in a general way, the procedures for application to pulsed burning, (2) increased significantly our understanding of the burn phenomenon by demonstrating that continuous burning can occur, and (3) indicated that steam can terminate continuous burning. Future actions recommended include: (1) modification of the code to perform continuous-burn analyses, which is demonstrated, (2) analyses to determine the type of burning (pulsed or continuous) that will exist in nuclear containments and the stable location if the burning is continuous, and (3) changes to the models for estimating burn parameters

Hydrogen-combustion analyses of large-scale tests

International Nuclear Information System (INIS)

Gido, R.G.; Koestel, A.

1986-01-01

This report uses results of the large-scale tests with turbulence performed by the Electric Power Research Institute at the Nevada Test Site to evaluate hydrogen burn-analysis procedures based on lumped-parameter codes like COMPARE-H2 and associated burn-parameter models. The test results (a) confirmed, in a general way, the procedures for application to pulsed burning, (b) increased significantly our understanding of the burn phenomenon by demonstrating that continuous burning can occur and (c) indicated that steam can terminate continuous burning. Future actions recommended include (a) modification of the code to perform continuous-burn analyses, which is demonstrated, (b) analyses to determine the type of burning (pulsed or continuous) that will exist in nuclear containments and the stable location if the burning is continuous, and (c) changes to the models for estimating burn parameters

Advances in compact manufacturing for shape and performance controllability of large-scale components-a review

Science.gov (United States)

Qin, Fangcheng; Li, Yongtang; Qi, Huiping; Ju, Li

2017-01-01

Research on compact manufacturing technology for shape and performance controllability of metallic components can realize the simplification and high-reliability of manufacturing process on the premise of satisfying the requirement of macro/micro-structure. It is not only the key paths in improving performance, saving material and energy, and green manufacturing of components used in major equipments, but also the challenging subjects in frontiers of advanced plastic forming. To provide a novel horizon for the manufacturing in the critical components is significant. Focused on the high-performance large-scale components such as bearing rings, flanges, railway wheels, thick-walled pipes, etc, the conventional processes and their developing situations are summarized. The existing problems including multi-pass heating, wasting material and energy, high cost and high-emission are discussed, and the present study unable to meet the manufacturing in high-quality components is also pointed out. Thus, the new techniques related to casting-rolling compound precise forming of rings, compact manufacturing for duplex-metal composite rings, compact manufacturing for railway wheels, and casting-extruding continuous forming of thick-walled pipes are introduced in detail, respectively. The corresponding research contents, such as casting ring blank, hot ring rolling, near solid-state pressure forming, hot extruding, are elaborated. Some findings in through-thickness microstructure evolution and mechanical properties are also presented. The components produced by the new techniques are mainly characterized by fine and homogeneous grains. Moreover, the possible directions for further development of those techniques are suggested. Finally, the key scientific problems are first proposed. All of these results and conclusions have reference value and guiding significance for the integrated control of shape and performance in advanced compact manufacturing.

Centrifugal fans: Similarity, scaling laws, and fan performance

Science.gov (United States)

Sardar, Asad Mohammad

Centrifugal fans are rotodynamic machines used for moving air continuously against moderate pressures through ventilation and air conditioning systems. There are five major topics presented in this thesis: (1) analysis of the fan scaling laws and consequences of dynamic similarity on modelling; (2) detailed flow visualization studies (in water) covering the flow path starting at the fan blade exit to the evaporator core of an actual HVAC fan scroll-diffuser module; (3) mean velocity and turbulence intensity measurements (flow field studies) at the inlet and outlet of large scale blower; (4) fan installation effects on overall fan performance and evaluation of fan testing methods; (5) two point coherence and spectral measurements conducted on an actual HVAC fan module for flow structure identification of possible aeroacoustic noise sources. A major objective of the study was to identity flow structures within the HVAC module that are responsible for noise and in particular "rumble noise" generation. Possible mechanisms for the generation of flow induced noise in the automotive HVAC fan module are also investigated. It is demonstrated that different modes of HVAC operation represent very different internal flow characteristics. This has implications on both fan HVAC airflow performance and noise characteristics. It is demonstrated from principles of complete dynamic similarity that fan scaling laws require that Reynolds, number matching is a necessary condition for developing scale model fans or fan test facilities. The physical basis for the fan scaling laws derived was established from both pure dimensional analysis and also from the fundamental equations of fluid motion. Fan performance was measured in a three times scale model (large scale blower) in air of an actual forward curved automotive HVAC blower. Different fan testing methods (based on AMCA fan test codes) were compared on the basis of static pressure measurements. Also, the flow through an actual HVAC

Constructing large scale SCI-based processing systems by switch elements

International Nuclear Information System (INIS)

Wu, B.; Kristiansen, E.; Skaali, B.; Bogaerts, A.; Divia, R.; Mueller, H.

1993-05-01

The goal of this paper is to study some of the design criteria for the switch elements to form the interconnection of large scale SCI-based processing systems. The approved IEEE standard 1596 makes it possible to couple up to 64K nodes together. In order to connect thousands of nodes to construct large scale SCI-based processing systems, one has to interconnect these nodes by switch elements to form different topologies. A summary of the requirements and key points of interconnection networks and switches is presented. Two models of the SCI switch elements are proposed. The authors investigate several examples of systems constructed for 4-switches with simulations and the results are analyzed. Some issues and enhancements are discussed to provide the ideas behind the switch design that can improve performance and reduce latency. 29 refs., 11 figs., 3 tabs

Large scale particle simulations in a virtual memory computer

International Nuclear Information System (INIS)

Gray, P.C.; Million, R.; Wagner, J.S.; Tajima, T.

1983-01-01

Virtual memory computers are capable of executing large-scale particle simulations even when the memory requirements exceeds the computer core size. The required address space is automatically mapped onto slow disc memory the the operating system. When the simulation size is very large, frequent random accesses to slow memory occur during the charge accumulation and particle pushing processes. Assesses to slow memory significantly reduce the excecution rate of the simulation. We demonstrate in this paper that with the proper choice of sorting algorithm, a nominal amount of sorting to keep physically adjacent particles near particles with neighboring array indices can reduce random access to slow memory, increase the efficiency of the I/O system, and hence, reduce the required computing time. (orig.)

Role of optometry school in single day large scale school vision testing

Science.gov (United States)

Anuradha, N; Ramani, Krishnakumar

2015-01-01

Background: School vision testing aims at identification and management of refractive errors. Large-scale school vision testing using conventional methods is time-consuming and demands a lot of chair time from the eye care professionals. A new strategy involving a school of optometry in single day large scale school vision testing is discussed. Aim: The aim was to describe a new approach of performing vision testing of school children on a large scale in a single day. Materials and Methods: A single day vision testing strategy was implemented wherein 123 members (20 teams comprising optometry students and headed by optometrists) conducted vision testing for children in 51 schools. School vision testing included basic vision screening, refraction, frame measurements, frame choice and referrals for other ocular problems. Results: A total of 12448 children were screened, among whom 420 (3.37%) were identified to have refractive errors. 28 (1.26%) children belonged to the primary, 163 to middle (9.80%), 129 (4.67%) to secondary and 100 (1.73%) to the higher secondary levels of education respectively. 265 (2.12%) children were referred for further evaluation. Conclusion: Single day large scale school vision testing can be adopted by schools of optometry to reach a higher number of children within a short span. PMID:25709271

Computational models of consumer confidence from large-scale online attention data: crowd-sourcing econometrics.

Science.gov (United States)

Dong, Xianlei; Bollen, Johan

2015-01-01

Economies are instances of complex socio-technical systems that are shaped by the interactions of large numbers of individuals. The individual behavior and decision-making of consumer agents is determined by complex psychological dynamics that include their own assessment of present and future economic conditions as well as those of others, potentially leading to feedback loops that affect the macroscopic state of the economic system. We propose that the large-scale interactions of a nation's citizens with its online resources can reveal the complex dynamics of their collective psychology, including their assessment of future system states. Here we introduce a behavioral index of Chinese Consumer Confidence (C3I) that computationally relates large-scale online search behavior recorded by Google Trends data to the macroscopic variable of consumer confidence. Our results indicate that such computational indices may reveal the components and complex dynamics of consumer psychology as a collective socio-economic phenomenon, potentially leading to improved and more refined economic forecasting.

Computational models of consumer confidence from large-scale online attention data: crowd-sourcing econometrics.

Directory of Open Access Journals (Sweden)

Xianlei Dong

Full Text Available Economies are instances of complex socio-technical systems that are shaped by the interactions of large numbers of individuals. The individual behavior and decision-making of consumer agents is determined by complex psychological dynamics that include their own assessment of present and future economic conditions as well as those of others, potentially leading to feedback loops that affect the macroscopic state of the economic system. We propose that the large-scale interactions of a nation's citizens with its online resources can reveal the complex dynamics of their collective psychology, including their assessment of future system states. Here we introduce a behavioral index of Chinese Consumer Confidence (C3I that computationally relates large-scale online search behavior recorded by Google Trends data to the macroscopic variable of consumer confidence. Our results indicate that such computational indices may reveal the components and complex dynamics of consumer psychology as a collective socio-economic phenomenon, potentially leading to improved and more refined economic forecasting.

Conference on Large Scale Optimization

CERN Document Server

Hearn, D; Pardalos, P

1994-01-01

On February 15-17, 1993, a conference on Large Scale Optimization, hosted by the Center for Applied Optimization, was held at the University of Florida. The con­ ference was supported by the National Science Foundation, the U. S. Army Research Office, and the University of Florida, with endorsements from SIAM, MPS, ORSA and IMACS. Forty one invited speakers presented papers on mathematical program­ ming and optimal control topics with an emphasis on algorithm development, real world applications and numerical results. Participants from Canada, Japan, Sweden, The Netherlands, Germany, Belgium, Greece, and Denmark gave the meeting an important international component. At­ tendees also included representatives from IBM, American Airlines, US Air, United Parcel Serice, AT & T Bell Labs, Thinking Machines, Army High Performance Com­ puting Research Center, and Argonne National Laboratory. In addition, the NSF sponsored attendance of thirteen graduate students from universities in the United States and abro...

Less is more: regularization perspectives on large scale machine learning

CERN Multimedia

CERN. Geneva

2017-01-01

Deep learning based techniques provide a possible solution at the expanse of theoretical guidance and, especially, of computational requirements. It is then a key challenge for large scale machine learning to devise approaches guaranteed to be accurate and yet computationally efficient. In this talk, we will consider a regularization perspectives on machine learning appealing to classical ideas in linear algebra and inverse problems to scale-up dramatically nonparametric methods such as kernel methods, often dismissed because of prohibitive costs. Our analysis derives optimal theoretical guarantees while providing experimental results at par or out-performing state of the art approaches.

Incipient multiple fault diagnosis in real time with applications to large-scale systems

International Nuclear Information System (INIS)

Chung, H.Y.; Bien, Z.; Park, J.H.; Seon, P.H.

1994-01-01

By using a modified signed directed graph (SDG) together with the distributed artificial neutral networks and a knowledge-based system, a method of incipient multi-fault diagnosis is presented for large-scale physical systems with complex pipes and instrumentations such as valves, actuators, sensors, and controllers. The proposed method is designed so as to (1) make a real-time incipient fault diagnosis possible for large-scale systems, (2) perform the fault diagnosis not only in the steady-state case but also in the transient case as well by using a concept of fault propagation time, which is newly adopted in the SDG model, (3) provide with highly reliable diagnosis results and explanation capability of faults diagnosed as in an expert system, and (4) diagnose the pipe damage such as leaking, break, or throttling. This method is applied for diagnosis of a pressurizer in the Kori Nuclear Power Plant (NPP) unit 2 in Korea under a transient condition, and its result is reported to show satisfactory performance of the method for the incipient multi-fault diagnosis of such a large-scale system in a real-time manner

PathlinesExplorer — Image-based exploration of large-scale pathline fields

KAUST Repository

Nagoor, Omniah H.

2015-10-25

PathlinesExplorer is a novel image-based tool, which has been designed to visualize large scale pathline fields on a single computer [7]. PathlinesExplorer integrates explorable images (EI) technique [4] with order-independent transparency (OIT) method [2]. What makes this method different is that it allows users to handle large data on a single workstation. Although it is a view-dependent method, PathlinesExplorer combines both exploration and modification of visual aspects without re-accessing the original huge data. Our approach is based on constructing a per-pixel linked list data structure in which each pixel contains a list of pathline segments. With this view-dependent method, it is possible to filter, color-code, and explore large-scale flow data in real-time. In addition, optimization techniques such as early-ray termination and deferred shading are applied, which further improves the performance and scalability of our approach.

Visual analysis of inter-process communication for large-scale parallel computing.

Science.gov (United States)

Muelder, Chris; Gygi, Francois; Ma, Kwan-Liu

2009-01-01

In serial computation, program profiling is often helpful for optimization of key sections of code. When moving to parallel computation, not only does the code execution need to be considered but also communication between the different processes which can induce delays that are detrimental to performance. As the number of processes increases, so does the impact of the communication delays on performance. For large-scale parallel applications, it is critical to understand how the communication impacts performance in order to make the code more efficient. There are several tools available for visualizing program execution and communications on parallel systems. These tools generally provide either views which statistically summarize the entire program execution or process-centric views. However, process-centric visualizations do not scale well as the number of processes gets very large. In particular, the most common representation of parallel processes is a Gantt char t with a row for each process. As the number of processes increases, these charts can become difficult to work with and can even exceed screen resolution. We propose a new visualization approach that affords more scalability and then demonstrate it on systems running with up to 16,384 processes.

Double inflation: A possible resolution of the large-scale structure problem

International Nuclear Information System (INIS)

Turner, M.S.; Villumsen, J.V.; Vittorio, N.; Silk, J.; Juszkiewicz, R.

1986-11-01

A model is presented for the large-scale structure of the universe in which two successive inflationary phases resulted in large small-scale and small large-scale density fluctuations. This bimodal density fluctuation spectrum in an Ω = 1 universe dominated by hot dark matter leads to large-scale structure of the galaxy distribution that is consistent with recent observational results. In particular, large, nearly empty voids and significant large-scale peculiar velocity fields are produced over scales of ∼100 Mpc, while the small-scale structure over ≤ 10 Mpc resembles that in a low density universe, as observed. Detailed analytical calculations and numerical simulations are given of the spatial and velocity correlations. 38 refs., 6 figs

Large-scale fracture mechancis testing -- requirements and possibilities

International Nuclear Information System (INIS)

Brumovsky, M.

1993-01-01

Application of fracture mechanics to very important and/or complicated structures, like reactor pressure vessels, brings also some questions about the reliability and precision of such calculations. These problems become more pronounced in cases of elastic-plastic conditions of loading and/or in parts with non-homogeneous materials (base metal and austenitic cladding, property gradient changes through material thickness) or with non-homogeneous stress fields (nozzles, bolt threads, residual stresses etc.). For such special cases some verification by large-scale testing is necessary and valuable. This paper discusses problems connected with planning of such experiments with respect to their limitations, requirements to a good transfer of received results to an actual vessel. At the same time, an analysis of possibilities of small-scale model experiments is also shown, mostly in connection with application of results between standard, small-scale and large-scale experiments. Experience from 30 years of large-scale testing in SKODA is used as an example to support this analysis. 1 fig

Ethics of large-scale change

DEFF Research Database (Denmark)

Arler, Finn

2006-01-01

, which kind of attitude is appropriate when dealing with large-scale changes like these from an ethical point of view. Three kinds of approaches are discussed: Aldo Leopold's mountain thinking, the neoclassical economists' approach, and finally the so-called Concentric Circle Theories approach...

Copy of Using Emulation and Simulation to Understand the Large-Scale Behavior of the Internet.

Energy Technology Data Exchange (ETDEWEB)

Adalsteinsson, Helgi; Armstrong, Robert C.; Chiang, Ken; Gentile, Ann C.; Lloyd, Levi; Minnich, Ronald G.; Vanderveen, Keith; Van Randwyk, Jamie A; Rudish, Don W.

2008-10-01

We report on the work done in the late-start LDRDUsing Emulation and Simulation toUnderstand the Large-Scale Behavior of the Internet. We describe the creation of a researchplatform that emulates many thousands of machines to be used for the study of large-scale inter-net behavior. We describe a proof-of-concept simple attack we performed in this environment.We describe the successful capture of a Storm bot and, from the study of the bot and furtherliterature search, establish large-scale aspects we seek to understand via emulation of Storm onour research platform in possible follow-on work. Finally, we discuss possible future work.3

Radiations: large scale monitoring in Japan

International Nuclear Information System (INIS)

Linton, M.; Khalatbari, A.

2011-01-01

As the consequences of radioactive leaks on their health are a matter of concern for Japanese people, a large scale epidemiological study has been launched by the Fukushima medical university. It concerns the two millions inhabitants of the Fukushima Prefecture. On the national level and with the support of public funds, medical care and follow-up, as well as systematic controls are foreseen, notably to check the thyroid of 360.000 young people less than 18 year old and of 20.000 pregnant women in the Fukushima Prefecture. Some measurements have already been performed on young children. Despite the sometimes rather low measures, and because they know that some parts of the area are at least as much contaminated as it was the case around Chernobyl, some people are reluctant to go back home

Internationalization Measures in Large Scale Research Projects

Science.gov (United States)

Soeding, Emanuel; Smith, Nancy

2017-04-01

Internationalization measures in Large Scale Research Projects Large scale research projects (LSRP) often serve as flagships used by universities or research institutions to demonstrate their performance and capability to stakeholders and other interested parties. As the global competition among universities for the recruitment of the brightest brains has increased, effective internationalization measures have become hot topics for universities and LSRP alike. Nevertheless, most projects and universities are challenged with little experience on how to conduct these measures and make internationalization an cost efficient and useful activity. Furthermore, those undertakings permanently have to be justified with the Project PIs as important, valuable tools to improve the capacity of the project and the research location. There are a variety of measures, suited to support universities in international recruitment. These include e.g. institutional partnerships, research marketing, a welcome culture, support for science mobility and an effective alumni strategy. These activities, although often conducted by different university entities, are interlocked and can be very powerful measures if interfaced in an effective way. On this poster we display a number of internationalization measures for various target groups, identify interfaces between project management, university administration, researchers and international partners to work together, exchange information and improve processes in order to be able to recruit, support and keep the brightest heads to your project.

A novel artificial fish swarm algorithm for solving large-scale reliability-redundancy application problem.

Science.gov (United States)

He, Qiang; Hu, Xiangtao; Ren, Hong; Zhang, Hongqi

2015-11-01

A novel artificial fish swarm algorithm (NAFSA) is proposed for solving large-scale reliability-redundancy allocation problem (RAP). In NAFSA, the social behaviors of fish swarm are classified in three ways: foraging behavior, reproductive behavior, and random behavior. The foraging behavior designs two position-updating strategies. And, the selection and crossover operators are applied to define the reproductive ability of an artificial fish. For the random behavior, which is essentially a mutation strategy, the basic cloud generator is used as the mutation operator. Finally, numerical results of four benchmark problems and a large-scale RAP are reported and compared. NAFSA shows good performance in terms of computational accuracy and computational efficiency for large scale RAP. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Gauging policy-driven large-scale vegetation restoration programmes under a changing environment: Their effectiveness and socio-economic relationships.

Science.gov (United States)

Li, Ting; Lü, Yihe; Fu, Bojie; Comber, Alexis J; Harris, Paul; Wu, Lianhai

2017-12-31

Large-scale ecological restoration has been widely accepted globally as an effective strategy for combating environmental crises and to facilitate sustainability. Assessing the effectiveness of ecological restoration is vital for researchers, practitioners, and policy-makers. However, few practical tools are available to perform such tasks, particularly for large-scale restoration programmes in complex socio-ecological systems. By taking a "before and after" design, this paper formulates a composite index (E j ) based on comparing the trends of vegetation cover and vegetation productivity to assess ecological restoration effectiveness. The index reveals the dynamic and spatially heterogenic process of vegetation restoration across different time periods, which can be informative for ecological restoration management at regional scales. Effectiveness together with its relationship to socio-economic factors is explored via structural equation modeling for three time periods. The results indicate that the temporal scale is a crucial factor in representing restoration effectiveness, and that the effects of socio-economic factors can also vary with time providing insight for improving restoration effectiveness. A dual-track strategy, which promotes the development of tertiary industry in absorbing the rural labor force together with improvements in agricultural practices, is proposed as a promising strategy for enhancing restoration effectiveness. In this process, timely and long-term ecological restoration monitoring is advocated, so that the success and sustainability of such programmes is ensured, together with more informative decision making where socio-ecological interactions at differing temporal scales are key concerns. Copyright © 2017 Elsevier B.V. All rights reserved.

Performance of large-scale scientific applications on the IBM ASCI Blue-Pacific system

International Nuclear Information System (INIS)

Mirin, A.

1998-01-01

The IBM ASCI Blue-Pacific System is a scalable, distributed/shared memory architecture designed to reach multi-teraflop performance. The IBM SP pieces together a large number of nodes, each having a modest number of processors. The system is designed to accommodate a mixed programming model as well as a pure message-passing paradigm. We examine a number of applications on this architecture and evaluate their performance and scalability

A Heuristic Approach to Author Name Disambiguation in Bibliometrics Databases for Large-scale Research Assessments

NARCIS (Netherlands)

D'Angelo, C.A.; Giuffrida, C.; Abramo, G.

2011-01-01

National exercises for the evaluation of research activity by universities are becoming regular practice in ever more countries. These exercises have mainly been conducted through the application of peer-review methods. Bibliometrics has not been able to offer a valid large-scale alternative because

Performance assessment of laboratory and field-scale multi-step passive treatment of iron-rich acid mine drainage for design improvement.

Science.gov (United States)

Rakotonimaro, Tsiverihasina V; Neculita, Carmen Mihaela; Bussière, Bruno; Genty, Thomas; Zagury, Gérald J

2018-04-17

Multi-step passive systems for the treatment of iron-rich acid mine drainage (Fe-rich AMD) perform satisfactorily at the laboratory scale. However, their field-scale application has revealed dissimilarities in performance, particularly with respect to hydraulic parameters. In this study, the assessment of factors potentially responsible for the variations in performance of laboratory and field-scale multi-step systems was undertaken. Three laboratory multi-step treatment scenarios, involving a combination of dispersed alkaline substrate (DAS) units, anoxic dolomitic drains, and passive biochemical reactors (PBRs), were set up in 10.7-L columns. The field-scale treatment consisted of two PBRs separated by a wood ash (WA) reactor. The parameters identified as possibly influencing the performances of the laboratory and field-scale experiments were the following: AMD chemistry (electrical conductivity and Fe and SO 4 2- concentrations), flow rate (Q), and saturated hydraulic conductivity (k sat ). Based on these findings, the design of an efficient passive multi-step treatment system is suggested to consider the following: (1) Fe pretreatment, using materials with high k sat and low HRT. If a PBR is to be used, the Fe load should be PBR/DAS filled with a mixture with at least 20% of neutralizing agent; (3) include Q and k sat (> 10 -3  cm/s) in the long-term prediction. Finally, mesocosm testing is strongly recommended prior to construction of full-scale systems for the treatment of Fe-rich AMD.

Simulation test of PIUS-type reactor with large scale experimental apparatus

International Nuclear Information System (INIS)

Tamaki, M.; Tsuji, Y.; Ito, T.; Tasaka, K.; Kukita, Yutaka

1995-01-01

A large scale experimental apparatus for simulating the PIUS-type reactor has been constructed keeping the volumetric scaling ratio to the realistic reactor model. Fundamental experiments such as a steady state operation and a pump trip simulation were performed. Experimental results were compared with those obtained by the small scale apparatus in JAERI. We have already reported the effectiveness of the feedback control for the primary loop pump speed (PI control) for the stable operation. In this paper this feedback system is modified and the PID control is introduced. This new system worked well for the operation of the PIUS-type reactor even in a rapid transient condition. (author)

Properties of large-scale methane/hydrogen jet fires

Energy Technology Data Exchange (ETDEWEB)

Studer, E. [CEA Saclay, DEN, LTMF Heat Transfer and Fluid Mech Lab, 91 - Gif-sur-Yvette (France); Jamois, D.; Leroy, G.; Hebrard, J. [INERIS, F-60150 Verneuil En Halatte (France); Jallais, S. [Air Liquide, F-78350 Jouy En Josas (France); Blanchetiere, V. [GDF SUEZ, 93 - La Plaine St Denis (France)

2009-12-15

A future economy based on reduction of carbon-based fuels for power generation and transportation may consider hydrogen as possible energy carrier Extensive and widespread use of hydrogen might require a pipeline network. The alternatives might be the use of the existing natural gas network or to design a dedicated network. Whatever the solution, mixing hydrogen with natural gas will modify the consequences of accidents, substantially The French National Research Agency (ANR) funded project called HYDROMEL focuses on these critical questions Within this project large-scale jet fires have been studied experimentally and numerically The main characteristics of these flames including visible length, radiation fluxes and blowout have been assessed. (authors)

A novel iron-lead redox flow battery for large-scale energy storage

Science.gov (United States)

Zeng, Y. K.; Zhao, T. S.; Zhou, X. L.; Wei, L.; Ren, Y. X.

2017-04-01

The redox flow battery (RFB) is one of the most promising large-scale energy storage technologies for the massive utilization of intermittent renewables especially wind and solar energy. This work presents a novel redox flow battery that utilizes inexpensive and abundant Fe(II)/Fe(III) and Pb/Pb(II) redox couples as redox materials. Experimental results show that both the Fe(II)/Fe(III) and Pb/Pb(II) redox couples have fast electrochemical kinetics in methanesulfonic acid, and that the coulombic efficiency and energy efficiency of the battery are, respectively, as high as 96.2% and 86.2% at 40 mA cm-2. Furthermore, the battery exhibits stable performance in terms of efficiencies and discharge capacities during the cycle test. The inexpensive redox materials, fast electrochemical kinetics and stable cycle performance make the present battery a promising candidate for large-scale energy storage applications.

A Report on Simulation-Driven Reliability and Failure Analysis of Large-Scale Storage Systems

Energy Technology Data Exchange (ETDEWEB)

Wan, Lipeng [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wang, Feiyi [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Oral, H. Sarp [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Vazhkudai, Sudharshan S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cao, Qing [Univ. of Tennessee, Knoxville, TN (United States)

2014-11-01

High-performance computing (HPC) storage systems provide data availability and reliability using various hardware and software fault tolerance techniques. Usually, reliability and availability are calculated at the subsystem or component level using limited metrics such as, mean time to failure (MTTF) or mean time to data loss (MTTDL). This often means settling on simple and disconnected failure models (such as exponential failure rate) to achieve tractable and close-formed solutions. However, such models have been shown to be insufficient in assessing end-to-end storage system reliability and availability. We propose a generic simulation framework aimed at analyzing the reliability and availability of storage systems at scale, and investigating what-if scenarios. The framework is designed for an end-to-end storage system, accommodating the various components and subsystems, their interconnections, failure patterns and propagation, and performs dependency analysis to capture a wide-range of failure cases. We evaluate the framework against a large-scale storage system that is in production and analyze its failure projections toward and beyond the end of lifecycle. We also examine the potential operational impact by studying how different types of components affect the overall system reliability and availability, and present the preliminary results

Functional Performance and Associations between Performance Tests and Neurological Assessment Differ in Men and Women with Parkinson's Disease.

Science.gov (United States)

Medijainen, Kadri; Pääsuke, Mati; Lukmann, Aet; Taba, Pille

2015-01-01

Neurological assessment of a patient with Parkinson's disease (PD) is expected to reflect upon functional performance. As women are known to report more limitations even for same observed functional performance level, present study was designed to examine whether associations between neurological assessments and functional performance differ across genders. 14 men and 14 women with PD participated. Functional performance was assessed by measuring walking speeds on 10-meter walk test (10MWT) and by performing timed-up-and-go-test (TUG). Neurological assessment included Hoehn and Yahr Scale (HY), Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Schwab and England Activities of Daily Living Scale (S-E), and Mini Mental State Examination (MMSE). In women with PD, Kendall's tau-b correlation analyses revealed significant correlations between functional performance tests and neurological assessment measures, with the exception in MMSE. No corresponding associations were found for men, although they demonstrated better functional performance, as expected. Men in similar clinical stage of the PD perform better on functional tests than women. Disease severity reflects upon functional performance differently in men and women with PD. Results indicate that when interpreting the assessment results of both functional performance and neurological assessment tests, the gender of the patient should be taken into consideration.

Large-scale runoff generation – parsimonious parameterisation using high-resolution topography

Directory of Open Access Journals (Sweden)

L. Gong

2011-08-01

Full Text Available World water resources have primarily been analysed by global-scale hydrological models in the last decades. Runoff generation in many of these models are based on process formulations developed at catchments scales. The division between slow runoff (baseflow and fast runoff is primarily governed by slope and spatial distribution of effective water storage capacity, both acting at very small scales. Many hydrological models, e.g. VIC, account for the spatial storage variability in terms of statistical distributions; such models are generally proven to perform well. The statistical approaches, however, use the same runoff-generation parameters everywhere in a basin. The TOPMODEL concept, on the other hand, links the effective maximum storage capacity with real-world topography. Recent availability of global high-quality, high-resolution topographic data makes TOPMODEL attractive as a basis for a physically-based runoff-generation algorithm at large scales, even if its assumptions are not valid in flat terrain or for deep groundwater systems. We present a new runoff-generation algorithm for large-scale hydrology based on TOPMODEL concepts intended to overcome these problems. The TRG (topography-derived runoff generation algorithm relaxes the TOPMODEL equilibrium assumption so baseflow generation is not tied to topography. TRG only uses the topographic index to distribute average storage to each topographic index class. The maximum storage capacity is proportional to the range of topographic index and is scaled by one parameter. The distribution of storage capacity within large-scale grid cells is obtained numerically through topographic analysis. The new topography-derived distribution function is then inserted into a runoff-generation framework similar VIC's. Different basin parts are parameterised by different storage capacities, and different shapes of the storage-distribution curves depend on their topographic characteristics. The TRG algorithm

Large-scale structure of the Universe

International Nuclear Information System (INIS)

Doroshkevich, A.G.

1978-01-01

The problems, discussed at the ''Large-scale Structure of the Universe'' symposium are considered on a popular level. Described are the cell structure of galaxy distribution in the Universe, principles of mathematical galaxy distribution modelling. The images of cell structures, obtained after reprocessing with the computer are given. Discussed are three hypothesis - vortical, entropic, adiabatic, suggesting various processes of galaxy and galaxy clusters origin. A considerable advantage of the adiabatic hypothesis is recognized. The relict radiation, as a method of direct studying the processes taking place in the Universe is considered. The large-scale peculiarities and small-scale fluctuations of the relict radiation temperature enable one to estimate the turbance properties at the pre-galaxy stage. The discussion of problems, pertaining to studying the hot gas, contained in galaxy clusters, the interactions within galaxy clusters and with the inter-galaxy medium, is recognized to be a notable contribution into the development of theoretical and observational cosmology

The TeraShake Computational Platform for Large-Scale Earthquake Simulations

Science.gov (United States)

Cui, Yifeng; Olsen, Kim; Chourasia, Amit; Moore, Reagan; Maechling, Philip; Jordan, Thomas

Geoscientific and computer science researchers with the Southern California Earthquake Center (SCEC) are conducting a large-scale, physics-based, computationally demanding earthquake system science research program with the goal of developing predictive models of earthquake processes. The computational demands of this program continue to increase rapidly as these researchers seek to perform physics-based numerical simulations of earthquake processes for larger meet the needs of this research program, a multiple-institution team coordinated by SCEC has integrated several scientific codes into a numerical modeling-based research tool we call the TeraShake computational platform (TSCP). A central component in the TSCP is a highly scalable earthquake wave propagation simulation program called the TeraShake anelastic wave propagation (TS-AWP) code. In this chapter, we describe how we extended an existing, stand-alone, wellvalidated, finite-difference, anelastic wave propagation modeling code into the highly scalable and widely used TS-AWP and then integrated this code into the TeraShake computational platform that provides end-to-end (initialization to analysis) research capabilities. We also describe the techniques used to enhance the TS-AWP parallel performance on TeraGrid supercomputers, as well as the TeraShake simulations phases including input preparation, run time, data archive management, and visualization. As a result of our efforts to improve its parallel efficiency, the TS-AWP has now shown highly efficient strong scaling on over 40K processors on IBM’s BlueGene/L Watson computer. In addition, the TSCP has developed into a computational system that is useful to many members of the SCEC community for performing large-scale earthquake simulations.

Large-scale demonstration of D ampersand D technologies

International Nuclear Information System (INIS)

Bhattacharyya, S.K.; Black, D.B.; Rose, R.W.

1997-01-01

It is becoming increasingly evident that new technologies will need to be utilized for decontamination and decommissioning (D ampersand D) activities in order to assure safe and cost effective operations. The magnitude of the international D ampersand D problem is sufficiently large in anticipated cost (100's of billions of dollars) and in elapsed time (decades), that the utilization of new technologies should lead to substantial improvements in cost and safety performance. Adoption of new technologies in the generally highly contaminated D ampersand D environments requires assurances that the technology will perform as advertised. Such assurances can be obtained from demonstrations of the technology in environments that are similar to the actual environments without being quite as contaminated and hazardous. The Large Scale Demonstration Project (LSDP) concept was designed to provide such a function. The first LSDP funded by the U.S. Department Of Energy's Environmental Management Office (EM) was on the Chicago Pile 5 (CP-5) Reactor at Argonne National Laboratory. The project, conducted by a Strategic Alliance for Environmental Restoration, has completed demonstrations of 10 D ampersand D technologies and is in the process of comparing the performance to baseline technologies. At the conclusion of the project, a catalog of performance comparisons of these technologies will be developed that will be suitable for use by future D ampersand D planners

Sodium-immersed self-cooled electromagnetic pump design and development of a large-scale coil for high temperature

International Nuclear Information System (INIS)

Oto, Akihiro; Naohara, Nobuyuki; Ishida, Masayoshi; Katsuki, Kenji; Kumazawa, Ryouji

1995-01-01

A sodium-immersed, self-cooled electromagnetic (EM) pump was recently studied as a prospective innovative technology to simplify a fast breeder reactor plant system. The EM pump for a primary pump, a pump type, was designed, and the structural concept and the system performance were clarified. For the flow control method, a constant voltage/frequency method was preferable from the point of view of pump performance and efficiency. The insulation life was tested on a large-scale coil at high temperature as part of the development of a large-capacity EM pump. Mechanical and electrical damage were not observed, and the insulation performance was quite good. The insulation system could also be applied to large-scale coils

Characterizing Temperature Variability and Associated Large Scale Meteorological Patterns Across South America

Science.gov (United States)

Detzer, J.; Loikith, P. C.; Mechoso, C. R.; Barkhordarian, A.; Lee, H.

2017-12-01

South America's climate varies considerably owing to its large geographic range and diverse topographical features. Spanning the tropics to the mid-latitudes and from high peaks to tropical rainforest, the continent experiences an array of climate and weather patterns. Due to this considerable spatial extent, assessing temperature variability at the continent scale is particularly challenging. It is well documented in the literature that temperatures have been increasing across portions of South America in recent decades, and while there have been many studies that have focused on precipitation variability and change, temperature has received less scientific attention. Therefore, a more thorough understanding of the drivers of temperature variability is critical for interpreting future change. First, k-means cluster analysis is used to identify four primary modes of temperature variability across the continent, stratified by season. Next, composites of large scale meteorological patterns (LSMPs) are calculated for months assigned to each cluster. Initial results suggest that LSMPs, defined using meteorological variables such as sea level pressure (SLP), geopotential height, and wind, are able to identify synoptic scale mechanisms important for driving temperature variability at the monthly scale. Some LSMPs indicate a relationship with known recurrent modes of climate variability. For example, composites of geopotential height suggest that the Southern Annular Mode is an important, but not necessarily dominant, component of temperature variability over southern South America. This work will be extended to assess the drivers of temperature extremes across South America.

Solving Large-Scale TSP Using a Fast Wedging Insertion Partitioning Approach

Directory of Open Access Journals (Sweden)

Zuoyong Xiang

2015-01-01

Full Text Available A new partitioning method, called Wedging Insertion, is proposed for solving large-scale symmetric Traveling Salesman Problem (TSP. The idea of our proposed algorithm is to cut a TSP tour into four segments by nodes’ coordinate (not by rectangle, such as Strip, FRP, and Karp. Each node is located in one of their segments, which excludes four particular nodes, and each segment does not twist with other segments. After the partitioning process, this algorithm utilizes traditional construction method, that is, the insertion method, for each segment to improve the quality of tour, and then connects the starting node and the ending node of each segment to obtain the complete tour. In order to test the performance of our proposed algorithm, we conduct the experiments on various TSPLIB instances. The experimental results show that our proposed algorithm in this paper is more efficient for solving large-scale TSPs. Specifically, our approach is able to obviously reduce the time complexity for running the algorithm; meanwhile, it will lose only about 10% of the algorithm’s performance.

Unified Tractable Model for Large-Scale Networks Using Stochastic Geometry: Analysis and Design

KAUST Repository

Afify, Laila H.

2016-12-01

The ever-growing demands for wireless technologies necessitate the evolution of next generation wireless networks that fulfill the diverse wireless users requirements. However, upscaling existing wireless networks implies upscaling an intrinsic component in the wireless domain; the aggregate network interference. Being the main performance limiting factor, it becomes crucial to develop a rigorous analytical framework to accurately characterize the out-of-cell interference, to reap the benefits of emerging networks. Due to the different network setups and key performance indicators, it is essential to conduct a comprehensive study that unifies the various network configurations together with the different tangible performance metrics. In that regard, the focus of this thesis is to present a unified mathematical paradigm, based on Stochastic Geometry, for large-scale networks with different antenna/network configurations. By exploiting such a unified study, we propose an efficient automated network design strategy to satisfy the desired network objectives. First, this thesis studies the exact aggregate network interference characterization, by accounting for each of the interferers signals in the large-scale network. Second, we show that the information about the interferers symbols can be approximated via the Gaussian signaling approach. The developed mathematical model presents twofold analysis unification for uplink and downlink cellular networks literature. It aligns the tangible decoding error probability analysis with the abstract outage probability and ergodic rate analysis. Furthermore, it unifies the analysis for different antenna configurations, i.e., various multiple-input multiple-output (MIMO) systems. Accordingly, we propose a novel reliable network design strategy that is capable of appropriately adjusting the network parameters to meet desired design criteria. In addition, we discuss the diversity-multiplexing tradeoffs imposed by differently favored

LAMMPS strong scaling performance optimization on Blue Gene/Q

Energy Technology Data Exchange (ETDEWEB)

Coffman, Paul; Jiang, Wei; Romero, Nichols A.

2014-11-12

LAMMPS "Large-scale Atomic/Molecular Massively Parallel Simulator" is an open-source molecular dynamics package from Sandia National Laboratories. Significant performance improvements in strong-scaling and time-to-solution for this application on IBM's Blue Gene/Q have been achieved through computational optimizations of the OpenMP versions of the short-range Lennard-Jones term of the CHARMM force field and the long-range Coulombic interaction implemented with the PPPM (particle-particle-particle mesh) algorithm, enhanced by runtime parameter settings controlling thread utilization. Additionally, MPI communication performance improvements were made to the PPPM calculation by re-engineering the parallel 3D FFT to use MPICH collectives instead of point-to-point. Performance testing was done using an 8.4-million atom simulation scaling up to 16 racks on the Mira system at Argonne Leadership Computing Facility (ALCF). Speedups resulting from this effort were in some cases over 2x.

The use of soil moisture - remote sensing products for large-scale groundwater modeling and assessment

NARCIS (Netherlands)

Sutanudjaja, E.H.

2012-01-01

In this thesis, the possibilities of using spaceborne remote sensing for large-scale groundwater modeling are explored. We focus on a soil moisture product called European Remote Sensing Soil Water Index (ERS SWI, Wagner et al., 1999) - representing the upper profile soil moisture. As a test-bed, we

Homogenization of Large-Scale Movement Models in Ecology

Science.gov (United States)

Garlick, M.J.; Powell, J.A.; Hooten, M.B.; McFarlane, L.R.

2011-01-01

A difficulty in using diffusion models to predict large scale animal population dispersal is that individuals move differently based on local information (as opposed to gradients) in differing habitat types. This can be accommodated by using ecological diffusion. However, real environments are often spatially complex, limiting application of a direct approach. Homogenization for partial differential equations has long been applied to Fickian diffusion (in which average individual movement is organized along gradients of habitat and population density). We derive a homogenization procedure for ecological diffusion and apply it to a simple model for chronic wasting disease in mule deer. Homogenization allows us to determine the impact of small scale (10-100 m) habitat variability on large scale (10-100 km) movement. The procedure generates asymptotic equations for solutions on the large scale with parameters defined by small-scale variation. The simplicity of this homogenization procedure is striking when compared to the multi-dimensional homogenization procedure for Fickian diffusion,and the method will be equally straightforward for more complex models. ?? 2010 Society for Mathematical Biology.

The role of large-scale, extratropical dynamics in climate change

Energy Technology Data Exchange (ETDEWEB)

Shepherd, T.G. [ed.

1994-02-01

The climate modeling community has focused recently on improving our understanding of certain processes, such as cloud feedbacks and ocean circulation, that are deemed critical to climate-change prediction. Although attention to such processes is warranted, emphasis on these areas has diminished a general appreciation of the role played by the large-scale dynamics of the extratropical atmosphere. Lack of interest in extratropical dynamics may reflect the assumption that these dynamical processes are a non-problem as far as climate modeling is concerned, since general circulation models (GCMs) calculate motions on this scale from first principles. Nevertheless, serious shortcomings in our ability to understand and simulate large-scale dynamics exist. Partly due to a paucity of standard GCM diagnostic calculations of large-scale motions and their transports of heat, momentum, potential vorticity, and moisture, a comprehensive understanding of the role of large-scale dynamics in GCM climate simulations has not been developed. Uncertainties remain in our understanding and simulation of large-scale extratropical dynamics and their interaction with other climatic processes, such as cloud feedbacks, large-scale ocean circulation, moist convection, air-sea interaction and land-surface processes. To address some of these issues, the 17th Stanstead Seminar was convened at Bishop`s University in Lennoxville, Quebec. The purpose of the Seminar was to promote discussion of the role of large-scale extratropical dynamics in global climate change. Abstracts of the talks are included in this volume. On the basis of these talks, several key issues emerged concerning large-scale extratropical dynamics and their climatic role. Individual records are indexed separately for the database.

The role of large-scale, extratropical dynamics in climate change

International Nuclear Information System (INIS)

Shepherd, T.G.

1994-02-01

The climate modeling community has focused recently on improving our understanding of certain processes, such as cloud feedbacks and ocean circulation, that are deemed critical to climate-change prediction. Although attention to such processes is warranted, emphasis on these areas has diminished a general appreciation of the role played by the large-scale dynamics of the extratropical atmosphere. Lack of interest in extratropical dynamics may reflect the assumption that these dynamical processes are a non-problem as far as climate modeling is concerned, since general circulation models (GCMs) calculate motions on this scale from first principles. Nevertheless, serious shortcomings in our ability to understand and simulate large-scale dynamics exist. Partly due to a paucity of standard GCM diagnostic calculations of large-scale motions and their transports of heat, momentum, potential vorticity, and moisture, a comprehensive understanding of the role of large-scale dynamics in GCM climate simulations has not been developed. Uncertainties remain in our understanding and simulation of large-scale extratropical dynamics and their interaction with other climatic processes, such as cloud feedbacks, large-scale ocean circulation, moist convection, air-sea interaction and land-surface processes. To address some of these issues, the 17th Stanstead Seminar was convened at Bishop's University in Lennoxville, Quebec. The purpose of the Seminar was to promote discussion of the role of large-scale extratropical dynamics in global climate change. Abstracts of the talks are included in this volume. On the basis of these talks, several key issues emerged concerning large-scale extratropical dynamics and their climatic role. Individual records are indexed separately for the database

AUSERA: Large-Scale Automated Security Risk Assessment of Global Mobile Banking Apps

OpenAIRE

Chen, Sen; Meng, Guozhu; Su, Ting; Fan, Lingling; Xue, Yinxing; Liu, Yang; Xu, Lihua; Xue, Minhui; Li, Bo; Hao, Shuang

2018-01-01

Contemporary financial technology (FinTech) that enables cashless mobile payment has been widely adopted by financial institutions, such as banks, due to its convenience and efficiency. However, FinTech has also made massive and dynamic transactions susceptible to security risks. Given large financial losses caused by such vulnerabilities, regulatory technology (RegTech) has been developed, but more comprehensive security risk assessment is specifically desired to develop robust, scalable, an...

Scaling up: Assessing social impacts at the macro-scale

International Nuclear Information System (INIS)

Schirmer, Jacki

2011-01-01

Social impacts occur at various scales, from the micro-scale of the individual to the macro-scale of the community. Identifying the macro-scale social changes that results from an impacting event is a common goal of social impact assessment (SIA), but is challenging as multiple factors simultaneously influence social trends at any given time, and there are usually only a small number of cases available for examination. While some methods have been proposed for establishing the contribution of an impacting event to macro-scale social change, they remain relatively untested. This paper critically reviews methods recommended to assess macro-scale social impacts, and proposes and demonstrates a new approach. The 'scaling up' method involves developing a chain of logic linking change at the individual/site scale to the community scale. It enables a more problematised assessment of the likely contribution of an impacting event to macro-scale social change than previous approaches. The use of this approach in a recent study of change in dairy farming in south east Australia is described.

Status: Large-scale subatmospheric cryogenic systems

International Nuclear Information System (INIS)

Peterson, T.

1989-01-01

In the late 1960's and early 1970's an interest in testing and operating RF cavities at 1.8K motivated the development and construction of four large (300 Watt) 1.8K refrigeration systems. in the past decade, development of successful superconducting RF cavities and interest in obtaining higher magnetic fields with the improved Niobium-Titanium superconductors has once again created interest in large-scale 1.8K refrigeration systems. The L'Air Liquide plant for Tore Supra is a recently commissioned 300 Watt 1.8K system which incorporates new technology, cold compressors, to obtain the low vapor pressure for low temperature cooling. CEBAF proposes to use cold compressors to obtain 5KW at 2.0K. Magnetic refrigerators of 10 Watt capacity or higher at 1.8K are now being developed. The state of the art of large-scale refrigeration in the range under 4K will be reviewed. 28 refs., 4 figs., 7 tabs

HiQuant: Rapid Postquantification Analysis of Large-Scale MS-Generated Proteomics Data.

Science.gov (United States)

Bryan, Kenneth; Jarboui, Mohamed-Ali; Raso, Cinzia; Bernal-Llinares, Manuel; McCann, Brendan; Rauch, Jens; Boldt, Karsten; Lynn, David J

2016-06-03

Recent advances in mass-spectrometry-based proteomics are now facilitating ambitious large-scale investigations of the spatial and temporal dynamics of the proteome; however, the increasing size and complexity of these data sets is overwhelming current downstream computational methods, specifically those that support the postquantification analysis pipeline. Here we present HiQuant, a novel application that enables the design and execution of a postquantification workflow, including common data-processing steps, such as assay normalization and grouping, and experimental replicate quality control and statistical analysis. HiQuant also enables the interpretation of results generated from large-scale data sets by supporting interactive heatmap analysis and also the direct export to Cytoscape and Gephi, two leading network analysis platforms. HiQuant may be run via a user-friendly graphical interface and also supports complete one-touch automation via a command-line mode. We evaluate HiQuant's performance by analyzing a large-scale, complex interactome mapping data set and demonstrate a 200-fold improvement in the execution time over current methods. We also demonstrate HiQuant's general utility by analyzing proteome-wide quantification data generated from both a large-scale public tyrosine kinase siRNA knock-down study and an in-house investigation into the temporal dynamics of the KSR1 and KSR2 interactomes. Download HiQuant, sample data sets, and supporting documentation at http://hiquant.primesdb.eu .

Large-scale weakly supervised object localization via latent category learning.

Science.gov (United States)

Chong Wang; Kaiqi Huang; Weiqiang Ren; Junge Zhang; Maybank, Steve

2015-04-01

Localizing objects in cluttered backgrounds is challenging under large-scale weakly supervised conditions. Due to the cluttered image condition, objects usually have large ambiguity with backgrounds. Besides, there is also a lack of effective algorithm for large-scale weakly supervised localization in cluttered backgrounds. However, backgrounds contain useful latent information, e.g., the sky in the aeroplane class. If this latent information can be learned, object-background ambiguity can be largely reduced and background can be suppressed effectively. In this paper, we propose the latent category learning (LCL) in large-scale cluttered conditions. LCL is an unsupervised learning method which requires only image-level class labels. First, we use the latent semantic analysis with semantic object representation to learn the latent categories, which represent objects, object parts or backgrounds. Second, to determine which category contains the target object, we propose a category selection strategy by evaluating each category's discrimination. Finally, we propose the online LCL for use in large-scale conditions. Evaluation on the challenging PASCAL Visual Object Class (VOC) 2007 and the large-scale imagenet large-scale visual recognition challenge 2013 detection data sets shows that the method can improve the annotation precision by 10% over previous methods. More importantly, we achieve the detection precision which outperforms previous results by a large margin and can be competitive to the supervised deformable part model 5.0 baseline on both data sets.