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Efficient modelling of natural gas pipeline on electromagnetic transient simulation programs

IET RENEWABLE POWER GENERATION 2023年第1期17卷 186-198页

作者： Song, Ruikai Xia, Yue Chen, Ying Du, Songhuai Strunz, Kai Song, Yankan Fang, Wang China Agr Univ Coll Informat & Elect Engn Beijing 100089 Peoples R China Tsinghua Univ Dept Elect Engn Beijing Peoples R China Tech Univ Berlin Dept Elect Engn & Comp Sci Berlin Germany Tsinghua Univ Sichuan Energy Internet Res Inst Chengdu Peoples R China

Electromagnetic transient programs (EMTPs) are widely used for simulating electromagnetic transient in power systems. With the increasing interest in integrated energy system (IES), it would be beneficial to extend the scope of EMTP-type application to multi-physics transients in integrated electrical and gas networks. An efficient and accurate model of gas pipeline is proposed in EMTP for the simulation of pneumatic transients. The pipeline is split into a number of segments using spatial discretization. Analogies between pneumatic and electric quantities, such as flow and pressure, current, and voltage, are used to create a circuit representation of pipe segment. The pipeline is represented by a distributed-element model. In order to enhance the computational efficiency, the nodal equation for pipeline model is reformulated. The pipeline model appears as a two-port Norton equivalent with constant admittances. Case studies are performed to demonstrate the accuracy and efficiency of the proposed pipeline model. The implementation of the proposed pipeline model in the EMTP-type program power systems computer aided design (PSCAD) enables the analysis of diverse transients in integrated electrical and gas systems (IEGSs).

关键词： EMTP-type program power system computer Power system management, operation and economics power system transients integrated energy system pipeline model pneumatic quantities computational efficiency natural gas diverse transients electric quantities pipes integrated electrical gas systems pneumatic transients power system simulation distributed-element model Power engineering computing natural gas pipeline electromagnetic transient programs integrated electrical gas networks multiphysics transients electromagnetic transient simulation programs pipelines EMTP

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The illegal trade in European eels: outsourcing, funding, and complex symbiotic-antithetical relationships

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TRENDS IN ORGANIZED CRIME 2023年第3期26卷 293-307页

作者： Alonso, Aitor Ibanez van Uhm, Daan P. Univ Utrecht Willem Pompe Inst Utrecht Netherlands

Whilst traditionally, the study of the illegal wildlife trade has been focused on species that consider the role of the Western world as a consumer or transit hub, the study of the illegal trade in European eels is a landmark opportunity to deem the role of Europe as a source area for wildlife trafficking. Based on a qualitative methods research design, this case study delves into the nature of the illegal trade in European eels. In the context of globalization, a global eel market developed at the same time as stocks decreased sharply. The process of criminalization of the trade and fishing of eels, in combination with criminogenic asymmetries, has been facilitating opportunities for crime groups. In the legal-illegal continuum, upper- and underworld actors interact along the chain from rivers to worldwide consumers. This constant interaction fuels the illegal trade by providing the underworld with vital elements for its continuity, such as protection, finance, or laundering. In particular, this research focusses on the different legal-illegal interactions by looking at outsourcing, funding and complex symbiotic-antithetical relationships.

关键词： Green Criminology European eel Wildlife Crime pipeline model Legal-illegal interface

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FACILE: Fast, Accurate, and Interpretable Basic-Block Throughput Prediction 26

FACILE: Fast, Accurate, and Interpretable Basic-Block Throug...

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26th IEEE International Symposium on Workload Characterization (IISWC)

作者： Abel, Andreas Sharma, Shrey Reineke, Jan Saarland Univ Saarland Informat Campus Saarbrucken Germany

ISBN: (纸本)9798350303179

Basic-block throughput models such as uiCA, IACA, GRANITE, Ithemal, llvm-mca, OSACA, or CQA guide optimizing compilers and help performance engineers identify and eliminate bottlenecks. For this purpose, basic-block throughput models should ideally be fast, accurate, and interpretable. Recent advances have significantly improved accuracy: uiCA, the state-of-the-art model, achieves an error of about 1% relative to measurements across a wide range of microarchitectures. The computational efficiency of throughput models, which is equally important for widespread adoption, especially in compilers, has so far received little attention. In this paper, we introduce FACILE, an analytical throughput model that is fast, accurate, and interpretable. FACILE analyzes different potential bottlenecks independently and analytically. Due to its compositional nature, FACILE's predictions directly pinpoint the bottlenecks. We evaluate FACILE on a wide range of microarchitectures and show that it is almost two orders of magnitude faster than existing models while achieving state-of-the-art accuracy.

关键词： basic block performance pipeline model throughput prediction

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uiCA: Accurate Throughput Prediction of Basic Blocks on Recent Intel Microarchitectures 22

uiCA: Accurate Throughput Prediction of Basic Blocks on Rece...

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36th ACM International Conference on Supercomputing (ICS)

作者： Abel, Andreas Reineke, Jan Saarland Univ Saarland Informat Campus Saarbrucken Germany

ISBN: (纸本)9781450392815

Performance models that statically predict the steady-state throughput of basic blocks on particular microarchitectures, such as IACA, Ithemal, llvm-mca, OSACA, or CQA, can guide optimizing compilers and aid manual software optimization. However, their utility heavily depends on the accuracy of their predictions. The average error of existing models compared to measurements on the actual hardware has been shown to lie between 9% and 36%. But how good is this? To answer this question, we propose an extremely simple analytical throughput model that may serve as a baseline. Surprisingly, this model is already competitive with the state of the art, indicating that there is significant potential for improvement. To explore this potential, we develop a simulation-based throughput predictor. To this end, we propose a detailed parametric pipeline model that supports all Intel Core microarchitecture generations released between 2011 and 2021. We evaluate our predictor on an improved version of the BHive benchmark suite and show that its predictions are usually within 1% of measurement results, improving upon prior models by roughly an order of magnitude. The experimental evaluation also demonstrates that several microarchitectural details considered to be rather insignificant in previous work, are in fact essential for accurate prediction. Our throughput predictor is available as open source.

关键词： performance throughput prediction simulation pipeline model benchmarking optimization

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GroPipe: A Grouped pipeline Hybrid Parallel Method for Accelerating DCNNs Training

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IEEE Transactions on Computers 2025年第7期74卷 2487-2500页

作者： Liu, Bin Ma, Yongyao Hu, Zijian Ji, Zeyu He, Zhenli Li, Keqin Northwest A&F University College of Information Engineering Shaanxi Yangling712100 China Shaanxi Engineering Research Center of Agricultural Information Intelligent Perception and Analysis Shaanxi Key Laboratory of Agricultural Information Perception and Intelligent Service Key Laboratory of Agricultural Internet of Things Ministry of Agriculture and Rural Affairs China Yunnan University Yunnan Key Laboratory of Software Engineering Kunming650091 China Yunnan University School of Software Kunming650091 China State University of New York Department of Computer Science New PaltzNY12561 United States

Training large Deep Convolutional Neural Networks (DCNNs) with increasingly large datasets to improve model accuracy has become extremely time-consuming. Distributed training methods, such as data parallelism (DP) and pipeline model parallelism (PMP), offer potential solutions but face challenges like load imbalance and significant communication overhead. This paper introduces GroPipe, a novel architecture that synergistically integrates PMP and DP, markedly improving training speeds. GroPipe employs an automatic model partitioning algorithm based on a performance projection technique, ensuring load balance and facilitating quantitative performance evaluation in PMP. Additionally, it adopts a group-based delayed asynchronous communication strategy to efficiently reduce communication overhead in DP. Using the ResNet and VGG models with the ImageNet dataset, extensive experiments are performed on an 8-GPU server and demonstrate GroPipe’s effectiveness. GroPipe achieves substantial improvements in time to accuracy, showing an average improvement of 42.2% and 14.0% on the ResNet series, and 79.2% and 43.9% on the VGG series, without compromising Top-1 accuracy. © 1968-2012 IEEE.

关键词： Training Computational modeling Parallel Processing Load modeling pipelines Data models Computers Memory Management Asynchronous Communication Resource Management Delayed Asynchronous Communication Deep Convolutional Neural Networks Hybrid Parallelism pipelined model Parallelism Deep Convolutional Neural Network Training Methods Training Speed Load Balancing Image Net Dataset Parallel Data Communication Overhead Partition model Partitioning Algorithm Top 1 Accuracy pipeline model Load Imbalance Learning Rate Training Time Resource Utilization Parallelization model Convergence Memory Usage Training Efficiency Balanced Distribution Backward Pass Multiple GP Us Forward Pass Multiple Partitions Vertical Dimension Parallel Efficiency VGG 19 model Throughput Experiments Parallel Training Idle Time

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IAP-SpTV: An input-aware adaptive pipeline SpTV via GCN on CPU-GPU

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JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING 2023年第1期181卷

作者： Wang, Haotian Yang, Wangdong Hu, Rong Ouyang, Renqiu Li, Kenli Li, Keqin Hunan Univ Coll Comp Sci & Elect Engn Changsha 410082 Hunan Peoples R China Natl Supercomp Ctr Changsha Changsha 410082 Hunan Peoples R China SUNY Coll New Paltz Dept Comp Sci New Paltz NY 12561 USA

Sparse tensor-times-vector (SpTV) is the core computation of tensor decomposition. Optimizing the computational performance of SpTV on CPU-GPU becomes a challenge due to the complexity of the non-zero element sparse distribution of the tensor. To solve this problem, we propose IAP-SpTV, an input aware adaptive pipeline SpTV via Graph Convolutional Network (GCN) on CPU-GPU. We first design the hybrid tensor format (HTF) and explore the challenges of the HTF-based pipeline SpTV algorithm. Second, we construct Slice-GCN to overcome the challenge of selecting a suitable format for each slice of HTF. Third, we construct an IAP-SpTV performance model for pipelining to achieve the maximum overlap between transfer and computation time during pipelining. Finally, we conduct experiments on two CPU-GPU platforms of different architectures to verify the correctness, effectiveness, and portability of IAP-SpTV. Overall, IAP-SpTV provides a significant performance improvement of about 24.85% to 58.42% compared to the state-of-the-art method.& COPY;2023 Elsevier Inc. All rights reserved.

关键词： Format selection GCN Hybrid format pipeline model SpTV

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A pipeline model to Discover Frequent Itemsets in an Hierarchical Systems

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INTERNATIONAL JOURNAL OF GRID AND DISTRIBUTED COMPUTING 2013年第4期6卷 19-38页

作者： Arour, Khedija Natl Inst Appl Sci & Technol Tunisia Dept Comp Sci & Math Tunis 1080 Tunisia

Like all the other fields of data processing, the modern information systems have integrated the results of the advanced technologies of the last decades. These systems contain implicit data which it will be necessary to extract and exploit, by using data Mining techniques. Mining association rules which trends to find interesting association or correlation relationships among large amounts of data is one of these techniques. It is a two-steps process, the first step finds all frequent itemsets and the second step constructs association rules from these frequent sets. The overall performance of mining association rules is determined by the first step which becomes the focus problem. This step is expensive with high demands for computation and data access. Parallel computing seems to have a natural role to play since parallel computers provides scalability. In this paper, we examine the issue of mining association rules among items in large databases transactions using the algorithm Apriori proposed by Agrawal. In this context, we propose a new parallel version of the Apriori algorithm of Agrawal, that is the main algorithm of each data mining technique. Parallel computing seems to have a natural role to play since parallel computers provides scalability. In fact, our objective of our work is to have an efficient parallel execution time that requires a delicate balance between program granularity and communication latency (synchronization overhead) between the different granules. Unlike previous work on parallelization of specific data mining algorithms, our approaches consist to discover the different granularity levels of parallelism and their impact on the performance. In this paper we focus on task and data parallelism (hybrid approach) under distributed memory. In particular, if communication latency is minimal then fine grain partitioning will yield the best performance. This is the case when data parallelism is used. If communication latency is large (as in a

关键词： Datamining Task parallelism Data parallelism pipeline model

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Unifying Fixed Code and Fixed Data Mapping of Load-Imbalanced pipelined Loops 16

Unifying Fixed Code and Fixed Data Mapping of Load-Imbalance...

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21st ACM SIGPLAN Symposium on Principles and Practice of Parallel Programming (PPoPP)

作者： Mastoras, Aristeidis Gross, Thomas R. ETH Dept Comp Sci CH-8092 Zurich Switzerland

ISBN: (纸本)9781450340922

Some loops with cross-iteration dependences can execute in parallel by pipelining. The loop body is partitioned into stages such that the data dependences are not violated and then the stages are mapped onto threads. Two well-known mapping techniques are fixed code and fixed data;they achieve high performance for load-balanced loops, but they fail to perform well for load-imbalanced loops. In this article, we present a novel hybrid mapping that eliminates drawbacks of both prior mapping techniques and enables dynamic scheduling of stages.

关键词： pipeline model mapping multi-threading: dynamic scheduling

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Tracing and identifying the impact of evidence - Use of a modified pipeline model

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WORLDVIEWS ON EVIDENCE-BASED NURSING 2008年第1期5卷 3-12页

作者： Wimpenny, Peter Johnson, Neil Walter, Isabel Wilkinson, Joyce E. Robert Gordon Univ Fac Hlth & Social Care Joanna Briggs Colaborating Ctr Aberdeen AB10 7QG Scotland Robert Gordon Univ Sch Nursing & Midwifery Aberdeen AB10 7QG Scotland Univ St Andrews Ctr Publ Policy & Management St Andrews KY16 9AJ Fife Scotland

Aim: This paper opens up a discussion about effective ways of tracing and identifying impact of evidence implementation in the field of nursing, through the use of Nutley et al.'s concept of an impact continuum, and Glasziou's pipeline model. Approach: Work to date on improving and evaluating the use of evidence in health care settings has tended to focus on evidence implementation as an endpoint or entity, often seen and measured in terms of change in practice. However, the direct application of evidence to practice is not straightforward. Glasziou's pipeline model of the different stages through which evidence flows, in the process of implementation, is critically reviewed in relation to five key issues: the type of evidence entering the pipeline;the linearity of the model;leakages and blockages in the pipeline;levels of impact;and impact measurement. The pipeline model is then combined with Nutley et al.'s continuum of impacts in order to present a Modified pipeline model. Discussion and Conclusions: The Modified pipeline model enables evidence implementation to be viewed as a process rather than an entity in itself, which in turn enables longitudinal assessment of barriers and facilitators to evidence "flow." By flow we mean the way in which evidence is transferred from reporting or publication stages to patient outcomes. It also allows identification of the multiple impacts that can occur through the process of evidence implementation, which may be impact on the way the nurse thinks about practice to the healing rate of a leg ulcer. Finally, the Modified model raises the issue of impacts beyond the pipeline, that is, those outcomes for patients that result from adherence to evidence-based care. This Modified pipeline model thus has the potential to support individuals and organizations in enhanced implementation planning, evaluation and management.

关键词： evidence-based practice pipeline model conceptual impact instrumental impact measurement research use

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modeling Wyoming's carbon dioxide pipeline network

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ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS 2008年第3期30卷 259-270页

作者： Towler, B. F. Agarwal, D. Mokhatab, S. Univ Wyoming Dept Chem & Petr Engn Laramie WY 82071 USA

A model of Wyoming's carbon dioxide pipeline network has been developed and used to analyze its capacity. The inlet to this pipeline is at Exxon Mobil's Shute Creek gas processing plant, and supercritical gas is then sent to Rangeley (Colorado), Rock Springs, Monell, Baroil and Salt Creek (all in Wyoming) fields. Along the way, the supercritical gas is cooled to a liquid. Here it is shown that the pipeline could easily accommodate a rate increase from the current 250 MMSCFD to 325 MMSCFD, utilizing the gas that is currently being vented from the Shute Creek intermediate separator, while maintaining the current inlet temperature and pressure. If new CO2 supplies became available it would be possible to increase the carbon dioxide throughput from 250 MMSCFD to 600 MMSCFD while extending the pipeline to other oilfields such as Beaver Creek and Hartzog Draw. In certain circumstances, this high rate may produce output pressures below the required miscibility pressures and also produce phase changes in the pipeline. However, this could be easily remedied by adding relatively modest horsepower pumps at intermediate pipeline locations.

关键词： CO2 enhanced oil recovery CO2 transport pipeline model Wyoming CO2 distribution

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